diff options
Diffstat (limited to 'poky/bitbake/doc')
20 files changed, 6638 insertions, 8 deletions
diff --git a/poky/bitbake/doc/.gitignore b/poky/bitbake/doc/.gitignore new file mode 100644 index 000000000..69fa449dd --- /dev/null +++ b/poky/bitbake/doc/.gitignore @@ -0,0 +1 @@ +_build/ diff --git a/poky/bitbake/doc/Makefile.sphinx b/poky/bitbake/doc/Makefile.sphinx new file mode 100644 index 000000000..c663c2954 --- /dev/null +++ b/poky/bitbake/doc/Makefile.sphinx @@ -0,0 +1,31 @@ +# Minimal makefile for Sphinx documentation +# + +# You can set these variables from the command line, and also +# from the environment for the first two. +SPHINXOPTS ?= +SPHINXBUILD ?= sphinx-build +SOURCEDIR = . +BUILDDIR = _build +DESTDIR = final + +# Put it first so that "make" without argument is like "make help". +help: + @$(SPHINXBUILD) -M help "$(SOURCEDIR)" "$(BUILDDIR)" $(SPHINXOPTS) $(O) + +.PHONY: help Makefile.sphinx clean publish + +publish: Makefile.sphinx html singlehtml + rm -rf $(BUILDDIR)/$(DESTDIR)/ + mkdir -p $(BUILDDIR)/$(DESTDIR)/ + cp -r $(BUILDDIR)/html/* $(BUILDDIR)/$(DESTDIR)/ + cp $(BUILDDIR)/singlehtml/index.html $(BUILDDIR)/$(DESTDIR)/singleindex.html + sed -i -e 's@index.html#@singleindex.html#@g' $(BUILDDIR)/$(DESTDIR)/singleindex.html + +clean: + @rm -rf $(BUILDDIR) + +# Catch-all target: route all unknown targets to Sphinx using the new +# "make mode" option. $(O) is meant as a shortcut for $(SPHINXOPTS). +%: Makefile.sphinx + @$(SPHINXBUILD) -M $@ "$(SOURCEDIR)" "$(BUILDDIR)" $(SPHINXOPTS) $(O) diff --git a/poky/bitbake/doc/_templates/breadcrumbs.html b/poky/bitbake/doc/_templates/breadcrumbs.html new file mode 100644 index 000000000..eb6244b74 --- /dev/null +++ b/poky/bitbake/doc/_templates/breadcrumbs.html @@ -0,0 +1,14 @@ +{% extends "!breadcrumbs.html" %} + +{% block breadcrumbs %} + <li> + <span class="doctype_switcher_placeholder">{{ doctype or 'single' }}</span> + <span class="version_switcher_placeholder">{{ release }}</span> + </li> + <li> »</li> + {% for doc in parents %} + <li><a href="{{ doc.link|e }}">{{ doc.title }}</a> »</li> + {% endfor %} + <li>{{ title }}</li> +{% endblock %} + diff --git a/poky/bitbake/doc/_templates/layout.html b/poky/bitbake/doc/_templates/layout.html new file mode 100644 index 000000000..308d5c7a2 --- /dev/null +++ b/poky/bitbake/doc/_templates/layout.html @@ -0,0 +1,7 @@ +{% extends "!layout.html" %} + +{% block extrabody %} +<div id="outdated-warning" style="text-align: center; background-color: #FFBABA; color: #6A0E0E;"> +</div> +{% endblock %} + diff --git a/poky/bitbake/doc/bitbake-user-manual/bitbake-user-manual-execution.rst b/poky/bitbake/doc/bitbake-user-manual/bitbake-user-manual-execution.rst new file mode 100644 index 000000000..019afd22f --- /dev/null +++ b/poky/bitbake/doc/bitbake-user-manual/bitbake-user-manual-execution.rst @@ -0,0 +1,733 @@ +.. SPDX-License-Identifier: CC-BY-2.5 + +========= +Execution +========= + +| + +The primary purpose for running BitBake is to produce some kind of +output such as a single installable package, a kernel, a software +development kit, or even a full, board-specific bootable Linux image, +complete with bootloader, kernel, and root filesystem. Of course, you +can execute the ``bitbake`` command with options that cause it to +execute single tasks, compile single recipe files, capture or clear +data, or simply return information about the execution environment. + +This chapter describes BitBake's execution process from start to finish +when you use it to create an image. The execution process is launched +using the following command form: :: + + $ bitbake target + +For information on +the BitBake command and its options, see ":ref:`The BitBake Command +<bitbake-user-manual-command>`" section. + +.. note:: + + Prior to executing BitBake, you should take advantage of available + parallel thread execution on your build host by setting the + :term:`BB_NUMBER_THREADS` variable in + your project's ``local.conf`` configuration file. + + A common method to determine this value for your build host is to run + the following: :: + + $ grep processor /proc/cpuinfo + + This command returns + the number of processors, which takes into account hyper-threading. + Thus, a quad-core build host with hyper-threading most likely shows + eight processors, which is the value you would then assign to + ``BB_NUMBER_THREADS``. + + A possibly simpler solution is that some Linux distributions (e.g. + Debian and Ubuntu) provide the ``ncpus`` command. + +Parsing the Base Configuration Metadata +======================================= + +The first thing BitBake does is parse base configuration metadata. Base +configuration metadata consists of your project's ``bblayers.conf`` file +to determine what layers BitBake needs to recognize, all necessary +``layer.conf`` files (one from each layer), and ``bitbake.conf``. The +data itself is of various types: + +- **Recipes:** Details about particular pieces of software. + +- **Class Data:** An abstraction of common build information (e.g. how to + build a Linux kernel). + +- **Configuration Data:** Machine-specific settings, policy decisions, + and so forth. Configuration data acts as the glue to bind everything + together. + +The ``layer.conf`` files are used to construct key variables such as +:term:`BBPATH` and :term:`BBFILES`. +``BBPATH`` is used to search for configuration and class files under the +``conf`` and ``classes`` directories, respectively. ``BBFILES`` is used +to locate both recipe and recipe append files (``.bb`` and +``.bbappend``). If there is no ``bblayers.conf`` file, it is assumed the +user has set the ``BBPATH`` and ``BBFILES`` directly in the environment. + +Next, the ``bitbake.conf`` file is located using the ``BBPATH`` variable +that was just constructed. The ``bitbake.conf`` file may also include +other configuration files using the ``include`` or ``require`` +directives. + +Prior to parsing configuration files, BitBake looks at certain +variables, including: + +- :term:`BB_ENV_WHITELIST` +- :term:`BB_ENV_EXTRAWHITE` +- :term:`BB_PRESERVE_ENV` +- :term:`BB_ORIGENV` +- :term:`BITBAKE_UI` + +The first four variables in this list relate to how BitBake treats shell +environment variables during task execution. By default, BitBake cleans +the environment variables and provides tight control over the shell +execution environment. However, through the use of these first four +variables, you can apply your control regarding the environment +variables allowed to be used by BitBake in the shell during execution of +tasks. See the +":ref:`bitbake-user-manual/bitbake-user-manual-metadata:Passing Information Into the Build Task Environment`" +section and the information about these variables in the variable +glossary for more information on how they work and on how to use them. + +The base configuration metadata is global and therefore affects all +recipes and tasks that are executed. + +BitBake first searches the current working directory for an optional +``conf/bblayers.conf`` configuration file. This file is expected to +contain a :term:`BBLAYERS` variable that is a +space-delimited list of 'layer' directories. Recall that if BitBake +cannot find a ``bblayers.conf`` file, then it is assumed the user has +set the ``BBPATH`` and ``BBFILES`` variables directly in the +environment. + +For each directory (layer) in this list, a ``conf/layer.conf`` file is +located and parsed with the :term:`LAYERDIR` variable +being set to the directory where the layer was found. The idea is these +files automatically set up :term:`BBPATH` and other +variables correctly for a given build directory. + +BitBake then expects to find the ``conf/bitbake.conf`` file somewhere in +the user-specified ``BBPATH``. That configuration file generally has +include directives to pull in any other metadata such as files specific +to the architecture, the machine, the local environment, and so forth. + +Only variable definitions and include directives are allowed in BitBake +``.conf`` files. Some variables directly influence BitBake's behavior. +These variables might have been set from the environment depending on +the environment variables previously mentioned or set in the +configuration files. The ":ref:`bitbake-user-manual/bitbake-user-manual-ref-variables:Variables Glossary`" +chapter presents a full list of +variables. + +After parsing configuration files, BitBake uses its rudimentary +inheritance mechanism, which is through class files, to inherit some +standard classes. BitBake parses a class when the inherit directive +responsible for getting that class is encountered. + +The ``base.bbclass`` file is always included. Other classes that are +specified in the configuration using the +:term:`INHERIT` variable are also included. BitBake +searches for class files in a ``classes`` subdirectory under the paths +in ``BBPATH`` in the same way as configuration files. + +A good way to get an idea of the configuration files and the class files +used in your execution environment is to run the following BitBake +command: :: + + $ bitbake -e > mybb.log + +Examining the top of the ``mybb.log`` +shows you the many configuration files and class files used in your +execution environment. + +.. note:: + + You need to be aware of how BitBake parses curly braces. If a recipe + uses a closing curly brace within the function and the character has + no leading spaces, BitBake produces a parsing error. If you use a + pair of curly braces in a shell function, the closing curly brace + must not be located at the start of the line without leading spaces. + + Here is an example that causes BitBake to produce a parsing error: :: + + fakeroot create_shar() { + cat << "EOF" > ${SDK_DEPLOY}/${TOOLCHAIN_OUTPUTNAME}.sh + usage() + { + echo "test" + ###### The following "}" at the start of the line causes a parsing error ###### + } + EOF + } + + Writing the recipe this way avoids the error: + fakeroot create_shar() { + cat << "EOF" > ${SDK_DEPLOY}/${TOOLCHAIN_OUTPUTNAME}.sh + usage() + { + echo "test" + ###### The following "}" with a leading space at the start of the line avoids the error ###### + } + EOF + } + +Locating and Parsing Recipes +============================ + +During the configuration phase, BitBake will have set +:term:`BBFILES`. BitBake now uses it to construct a +list of recipes to parse, along with any append files (``.bbappend``) to +apply. ``BBFILES`` is a space-separated list of available files and +supports wildcards. An example would be: :: + + BBFILES = "/path/to/bbfiles/*.bb /path/to/appends/*.bbappend" + +BitBake parses each +recipe and append file located with ``BBFILES`` and stores the values of +various variables into the datastore. + +.. note:: + + Append files are applied in the order they are encountered in BBFILES. + +For each file, a fresh copy of the base configuration is made, then the +recipe is parsed line by line. Any inherit statements cause BitBake to +find and then parse class files (``.bbclass``) using +:term:`BBPATH` as the search path. Finally, BitBake +parses in order any append files found in ``BBFILES``. + +One common convention is to use the recipe filename to define pieces of +metadata. For example, in ``bitbake.conf`` the recipe name and version +are used to set the variables :term:`PN` and +:term:`PV`: :: + + PN = "${@bb.parse.BBHandler.vars_from_file(d.getVar('FILE', False),d)[0] or 'defaultpkgname'}" + PV = "${@bb.parse.BBHandler.vars_from_file(d.getVar('FILE', False),d)[1] or '1.0'}" + +In this example, a recipe called "something_1.2.3.bb" would set +``PN`` to "something" and ``PV`` to "1.2.3". + +By the time parsing is complete for a recipe, BitBake has a list of +tasks that the recipe defines and a set of data consisting of keys and +values as well as dependency information about the tasks. + +BitBake does not need all of this information. It only needs a small +subset of the information to make decisions about the recipe. +Consequently, BitBake caches the values in which it is interested and +does not store the rest of the information. Experience has shown it is +faster to re-parse the metadata than to try and write it out to the disk +and then reload it. + +Where possible, subsequent BitBake commands reuse this cache of recipe +information. The validity of this cache is determined by first computing +a checksum of the base configuration data (see +:term:`BB_HASHCONFIG_WHITELIST`) and +then checking if the checksum matches. If that checksum matches what is +in the cache and the recipe and class files have not changed, BitBake is +able to use the cache. BitBake then reloads the cached information about +the recipe instead of reparsing it from scratch. + +Recipe file collections exist to allow the user to have multiple +repositories of ``.bb`` files that contain the same exact package. For +example, one could easily use them to make one's own local copy of an +upstream repository, but with custom modifications that one does not +want upstream. Here is an example: :: + + BBFILES = "/stuff/openembedded/*/*.bb /stuff/openembedded.modified/*/*.bb" + BBFILE_COLLECTIONS = "upstream local" + BBFILE_PATTERN_upstream = "^/stuff/openembedded/" + BBFILE_PATTERN_local = "^/stuff/openembedded.modified/" + BBFILE_PRIORITY_upstream = "5" BBFILE_PRIORITY_local = "10" + +.. note:: + + The layers mechanism is now the preferred method of collecting code. + While the collections code remains, its main use is to set layer + priorities and to deal with overlap (conflicts) between layers. + +.. _bb-bitbake-providers: + +Providers +========= + +Assuming BitBake has been instructed to execute a target and that all +the recipe files have been parsed, BitBake starts to figure out how to +build the target. BitBake looks through the ``PROVIDES`` list for each +of the recipes. A ``PROVIDES`` list is the list of names by which the +recipe can be known. Each recipe's ``PROVIDES`` list is created +implicitly through the recipe's :term:`PN` variable and +explicitly through the recipe's :term:`PROVIDES` +variable, which is optional. + +When a recipe uses ``PROVIDES``, that recipe's functionality can be +found under an alternative name or names other than the implicit ``PN`` +name. As an example, suppose a recipe named ``keyboard_1.0.bb`` +contained the following: :: + + PROVIDES += "fullkeyboard" + +The ``PROVIDES`` +list for this recipe becomes "keyboard", which is implicit, and +"fullkeyboard", which is explicit. Consequently, the functionality found +in ``keyboard_1.0.bb`` can be found under two different names. + +.. _bb-bitbake-preferences: + +Preferences +=========== + +The ``PROVIDES`` list is only part of the solution for figuring out a +target's recipes. Because targets might have multiple providers, BitBake +needs to prioritize providers by determining provider preferences. + +A common example in which a target has multiple providers is +"virtual/kernel", which is on the ``PROVIDES`` list for each kernel +recipe. Each machine often selects the best kernel provider by using a +line similar to the following in the machine configuration file: :: + + PREFERRED_PROVIDER_virtual/kernel = "linux-yocto" + +The default :term:`PREFERRED_PROVIDER` is the provider +with the same name as the target. BitBake iterates through each target +it needs to build and resolves them and their dependencies using this +process. + +Understanding how providers are chosen is made complicated by the fact +that multiple versions might exist for a given provider. BitBake +defaults to the highest version of a provider. Version comparisons are +made using the same method as Debian. You can use the +:term:`PREFERRED_VERSION` variable to +specify a particular version. You can influence the order by using the +:term:`DEFAULT_PREFERENCE` variable. + +By default, files have a preference of "0". Setting +``DEFAULT_PREFERENCE`` to "-1" makes the recipe unlikely to be used +unless it is explicitly referenced. Setting ``DEFAULT_PREFERENCE`` to +"1" makes it likely the recipe is used. ``PREFERRED_VERSION`` overrides +any ``DEFAULT_PREFERENCE`` setting. ``DEFAULT_PREFERENCE`` is often used +to mark newer and more experimental recipe versions until they have +undergone sufficient testing to be considered stable. + +When there are multiple “versions” of a given recipe, BitBake defaults +to selecting the most recent version, unless otherwise specified. If the +recipe in question has a +:term:`DEFAULT_PREFERENCE` set lower than +the other recipes (default is 0), then it will not be selected. This +allows the person or persons maintaining the repository of recipe files +to specify their preference for the default selected version. +Additionally, the user can specify their preferred version. + +If the first recipe is named ``a_1.1.bb``, then the +:term:`PN` variable will be set to “a”, and the +:term:`PV` variable will be set to 1.1. + +Thus, if a recipe named ``a_1.2.bb`` exists, BitBake will choose 1.2 by +default. However, if you define the following variable in a ``.conf`` +file that BitBake parses, you can change that preference: :: + + PREFERRED_VERSION_a = "1.1" + +.. note:: + + It is common for a recipe to provide two versions -- a stable, + numbered (and preferred) version, and a version that is automatically + checked out from a source code repository that is considered more + "bleeding edge" but can be selected only explicitly. + + For example, in the OpenEmbedded codebase, there is a standard, + versioned recipe file for BusyBox, ``busybox_1.22.1.bb``, but there + is also a Git-based version, ``busybox_git.bb``, which explicitly + contains the line :: + + DEFAULT_PREFERENCE = "-1" + + to ensure that the + numbered, stable version is always preferred unless the developer + selects otherwise. + +.. _bb-bitbake-dependencies: + +Dependencies +============ + +Each target BitBake builds consists of multiple tasks such as ``fetch``, +``unpack``, ``patch``, ``configure``, and ``compile``. For best +performance on multi-core systems, BitBake considers each task as an +independent entity with its own set of dependencies. + +Dependencies are defined through several variables. You can find +information about variables BitBake uses in the +:doc:`bitbake-user-manual-ref-variables` near the end of this manual. At a +basic level, it is sufficient to know that BitBake uses the +:term:`DEPENDS` and +:term:`RDEPENDS` variables when calculating +dependencies. + +For more information on how BitBake handles dependencies, see the +:ref:`bitbake-user-manual/bitbake-user-manual-metadata:Dependencies` +section. + +.. _ref-bitbake-tasklist: + +The Task List +============= + +Based on the generated list of providers and the dependency information, +BitBake can now calculate exactly what tasks it needs to run and in what +order it needs to run them. The +:ref:`bitbake-user-manual/bitbake-user-manual-execution:executing tasks` +section has more information on how BitBake chooses which task to +execute next. + +The build now starts with BitBake forking off threads up to the limit +set in the :term:`BB_NUMBER_THREADS` +variable. BitBake continues to fork threads as long as there are tasks +ready to run, those tasks have all their dependencies met, and the +thread threshold has not been exceeded. + +It is worth noting that you can greatly speed up the build time by +properly setting the ``BB_NUMBER_THREADS`` variable. + +As each task completes, a timestamp is written to the directory +specified by the :term:`STAMP` variable. On subsequent +runs, BitBake looks in the build directory within ``tmp/stamps`` and +does not rerun tasks that are already completed unless a timestamp is +found to be invalid. Currently, invalid timestamps are only considered +on a per recipe file basis. So, for example, if the configure stamp has +a timestamp greater than the compile timestamp for a given target, then +the compile task would rerun. Running the compile task again, however, +has no effect on other providers that depend on that target. + +The exact format of the stamps is partly configurable. In modern +versions of BitBake, a hash is appended to the stamp so that if the +configuration changes, the stamp becomes invalid and the task is +automatically rerun. This hash, or signature used, is governed by the +signature policy that is configured (see the +:ref:`bitbake-user-manual/bitbake-user-manual-execution:checksums (signatures)` +section for information). It is also +possible to append extra metadata to the stamp using the +``[stamp-extra-info]`` task flag. For example, OpenEmbedded uses this +flag to make some tasks machine-specific. + +.. note:: + + Some tasks are marked as "nostamp" tasks. No timestamp file is + created when these tasks are run. Consequently, "nostamp" tasks are + always rerun. + +For more information on tasks, see the +:ref:`bitbake-user-manual/bitbake-user-manual-metadata:tasks` section. + +Executing Tasks +=============== + +Tasks can be either a shell task or a Python task. For shell tasks, +BitBake writes a shell script to +``${``\ :term:`T`\ ``}/run.do_taskname.pid`` and then +executes the script. The generated shell script contains all the +exported variables, and the shell functions with all variables expanded. +Output from the shell script goes to the file +``${T}/log.do_taskname.pid``. Looking at the expanded shell functions in +the run file and the output in the log files is a useful debugging +technique. + +For Python tasks, BitBake executes the task internally and logs +information to the controlling terminal. Future versions of BitBake will +write the functions to files similar to the way shell tasks are handled. +Logging will be handled in a way similar to shell tasks as well. + +The order in which BitBake runs the tasks is controlled by its task +scheduler. It is possible to configure the scheduler and define custom +implementations for specific use cases. For more information, see these +variables that control the behavior: + +- :term:`BB_SCHEDULER` + +- :term:`BB_SCHEDULERS` + +It is possible to have functions run before and after a task's main +function. This is done using the ``[prefuncs]`` and ``[postfuncs]`` +flags of the task that lists the functions to run. + +.. _checksums: + +Checksums (Signatures) +====================== + +A checksum is a unique signature of a task's inputs. The signature of a +task can be used to determine if a task needs to be run. Because it is a +change in a task's inputs that triggers running the task, BitBake needs +to detect all the inputs to a given task. For shell tasks, this turns +out to be fairly easy because BitBake generates a "run" shell script for +each task and it is possible to create a checksum that gives you a good +idea of when the task's data changes. + +To complicate the problem, some things should not be included in the +checksum. First, there is the actual specific build path of a given task +- the working directory. It does not matter if the working directory +changes because it should not affect the output for target packages. The +simplistic approach for excluding the working directory is to set it to +some fixed value and create the checksum for the "run" script. BitBake +goes one step better and uses the +:term:`BB_HASHBASE_WHITELIST` variable +to define a list of variables that should never be included when +generating the signatures. + +Another problem results from the "run" scripts containing functions that +might or might not get called. The incremental build solution contains +code that figures out dependencies between shell functions. This code is +used to prune the "run" scripts down to the minimum set, thereby +alleviating this problem and making the "run" scripts much more readable +as a bonus. + +So far we have solutions for shell scripts. What about Python tasks? The +same approach applies even though these tasks are more difficult. The +process needs to figure out what variables a Python function accesses +and what functions it calls. Again, the incremental build solution +contains code that first figures out the variable and function +dependencies, and then creates a checksum for the data used as the input +to the task. + +Like the working directory case, situations exist where dependencies +should be ignored. For these cases, you can instruct the build process +to ignore a dependency by using a line like the following: :: + + PACKAGE_ARCHS[vardepsexclude] = "MACHINE" + +This example ensures that the +``PACKAGE_ARCHS`` variable does not depend on the value of ``MACHINE``, +even if it does reference it. + +Equally, there are cases where we need to add dependencies BitBake is +not able to find. You can accomplish this by using a line like the +following: :: + + PACKAGE_ARCHS[vardeps] = "MACHINE" + +This example explicitly +adds the ``MACHINE`` variable as a dependency for ``PACKAGE_ARCHS``. + +Consider a case with in-line Python, for example, where BitBake is not +able to figure out dependencies. When running in debug mode (i.e. using +``-DDD``), BitBake produces output when it discovers something for which +it cannot figure out dependencies. + +Thus far, this section has limited discussion to the direct inputs into +a task. Information based on direct inputs is referred to as the +"basehash" in the code. However, there is still the question of a task's +indirect inputs - the things that were already built and present in the +build directory. The checksum (or signature) for a particular task needs +to add the hashes of all the tasks on which the particular task depends. +Choosing which dependencies to add is a policy decision. However, the +effect is to generate a master checksum that combines the basehash and +the hashes of the task's dependencies. + +At the code level, there are a variety of ways both the basehash and the +dependent task hashes can be influenced. Within the BitBake +configuration file, we can give BitBake some extra information to help +it construct the basehash. The following statement effectively results +in a list of global variable dependency excludes - variables never +included in any checksum. This example uses variables from OpenEmbedded +to help illustrate the concept: :: + + BB_HASHBASE_WHITELIST ?= "TMPDIR FILE PATH PWD BB_TASKHASH BBPATH DL_DIR \ + SSTATE_DIR THISDIR FILESEXTRAPATHS FILE_DIRNAME HOME LOGNAME SHELL \ + USER FILESPATH STAGING_DIR_HOST STAGING_DIR_TARGET COREBASE PRSERV_HOST \ + PRSERV_DUMPDIR PRSERV_DUMPFILE PRSERV_LOCKDOWN PARALLEL_MAKE \ + CCACHE_DIR EXTERNAL_TOOLCHAIN CCACHE CCACHE_DISABLE LICENSE_PATH SDKPKGSUFFIX" + +The previous example excludes the work directory, which is part of +``TMPDIR``. + +The rules for deciding which hashes of dependent tasks to include +through dependency chains are more complex and are generally +accomplished with a Python function. The code in +``meta/lib/oe/sstatesig.py`` shows two examples of this and also +illustrates how you can insert your own policy into the system if so +desired. This file defines the two basic signature generators +OpenEmbedded-Core uses: "OEBasic" and "OEBasicHash". By default, there +is a dummy "noop" signature handler enabled in BitBake. This means that +behavior is unchanged from previous versions. ``OE-Core`` uses the +"OEBasicHash" signature handler by default through this setting in the +``bitbake.conf`` file: :: + + BB_SIGNATURE_HANDLER ?= "OEBasicHash" + +The "OEBasicHash" ``BB_SIGNATURE_HANDLER`` is the same as the "OEBasic" +version but adds the task hash to the stamp files. This results in any +metadata change that changes the task hash, automatically causing the +task to be run again. This removes the need to bump +:term:`PR` values, and changes to metadata automatically +ripple across the build. + +It is also worth noting that the end result of these signature +generators is to make some dependency and hash information available to +the build. This information includes: + +- ``BB_BASEHASH_task-``\ *taskname*: The base hashes for each task in the + recipe. + +- ``BB_BASEHASH_``\ *filename:taskname*: The base hashes for each + dependent task. + +- ``BBHASHDEPS_``\ *filename:taskname*: The task dependencies for + each task. + +- ``BB_TASKHASH``: The hash of the currently running task. + +It is worth noting that BitBake's "-S" option lets you debug BitBake's +processing of signatures. The options passed to -S allow different +debugging modes to be used, either using BitBake's own debug functions +or possibly those defined in the metadata/signature handler itself. The +simplest parameter to pass is "none", which causes a set of signature +information to be written out into ``STAMPS_DIR`` corresponding to the +targets specified. The other currently available parameter is +"printdiff", which causes BitBake to try to establish the closest +signature match it can (e.g. in the sstate cache) and then run +``bitbake-diffsigs`` over the matches to determine the stamps and delta +where these two stamp trees diverge. + +.. note:: + + It is likely that future versions of BitBake will provide other + signature handlers triggered through additional "-S" parameters. + +You can find more information on checksum metadata in the +:ref:`bitbake-user-manual/bitbake-user-manual-metadata:task checksums and setscene` +section. + +Setscene +======== + +The setscene process enables BitBake to handle "pre-built" artifacts. +The ability to handle and reuse these artifacts allows BitBake the +luxury of not having to build something from scratch every time. +Instead, BitBake can use, when possible, existing build artifacts. + +BitBake needs to have reliable data indicating whether or not an +artifact is compatible. Signatures, described in the previous section, +provide an ideal way of representing whether an artifact is compatible. +If a signature is the same, an object can be reused. + +If an object can be reused, the problem then becomes how to replace a +given task or set of tasks with the pre-built artifact. BitBake solves +the problem with the "setscene" process. + +When BitBake is asked to build a given target, before building anything, +it first asks whether cached information is available for any of the +targets it's building, or any of the intermediate targets. If cached +information is available, BitBake uses this information instead of +running the main tasks. + +BitBake first calls the function defined by the +:term:`BB_HASHCHECK_FUNCTION` variable +with a list of tasks and corresponding hashes it wants to build. This +function is designed to be fast and returns a list of the tasks for +which it believes in can obtain artifacts. + +Next, for each of the tasks that were returned as possibilities, BitBake +executes a setscene version of the task that the possible artifact +covers. Setscene versions of a task have the string "_setscene" appended +to the task name. So, for example, the task with the name ``xxx`` has a +setscene task named ``xxx_setscene``. The setscene version of the task +executes and provides the necessary artifacts returning either success +or failure. + +As previously mentioned, an artifact can cover more than one task. For +example, it is pointless to obtain a compiler if you already have the +compiled binary. To handle this, BitBake calls the +:term:`BB_SETSCENE_DEPVALID` function for +each successful setscene task to know whether or not it needs to obtain +the dependencies of that task. + +Finally, after all the setscene tasks have executed, BitBake calls the +function listed in +:term:`BB_SETSCENE_VERIFY_FUNCTION2` +with the list of tasks BitBake thinks has been "covered". The metadata +can then ensure that this list is correct and can inform BitBake that it +wants specific tasks to be run regardless of the setscene result. + +You can find more information on setscene metadata in the +:ref:`bitbake-user-manual/bitbake-user-manual-metadata:task checksums and setscene` +section. + +Logging +======= + +In addition to the standard command line option to control how verbose +builds are when execute, bitbake also supports user defined +configuration of the `Python +logging <https://docs.python.org/3/library/logging.html>`__ facilities +through the :term:`BB_LOGCONFIG` variable. This +variable defines a json or yaml `logging +configuration <https://docs.python.org/3/library/logging.config.html>`__ +that will be intelligently merged into the default configuration. The +logging configuration is merged using the following rules: + +- The user defined configuration will completely replace the default + configuration if top level key ``bitbake_merge`` is set to the value + ``False``. In this case, all other rules are ignored. + +- The user configuration must have a top level ``version`` which must + match the value of the default configuration. + +- Any keys defined in the ``handlers``, ``formatters``, or ``filters``, + will be merged into the same section in the default configuration, + with the user specified keys taking replacing a default one if there + is a conflict. In practice, this means that if both the default + configuration and user configuration specify a handler named + ``myhandler``, the user defined one will replace the default. To + prevent the user from inadvertently replacing a default handler, + formatter, or filter, all of the default ones are named with a prefix + of "``BitBake.``" + +- If a logger is defined by the user with the key ``bitbake_merge`` set + to ``False``, that logger will be completely replaced by user + configuration. In this case, no other rules will apply to that + logger. + +- All user defined ``filter`` and ``handlers`` properties for a given + logger will be merged with corresponding properties from the default + logger. For example, if the user configuration adds a filter called + ``myFilter`` to the ``BitBake.SigGen``, and the default configuration + adds a filter called ``BitBake.defaultFilter``, both filters will be + applied to the logger + +As an example, consider the following user logging configuration file +which logs all Hash Equivalence related messages of VERBOSE or higher to +a file called ``hashequiv.log`` :: + + { + "version": 1, + "handlers": { + "autobuilderlog": { + "class": "logging.FileHandler", + "formatter": "logfileFormatter", + "level": "DEBUG", + "filename": "hashequiv.log", + "mode": "w" + } + }, + "formatters": { + "logfileFormatter": { + "format": "%(name)s: %(levelname)s: %(message)s" + } + }, + "loggers": { + "BitBake.SigGen.HashEquiv": { + "level": "VERBOSE", + "handlers": ["autobuilderlog"] + }, + "BitBake.RunQueue.HashEquiv": { + "level": "VERBOSE", + "handlers": ["autobuilderlog"] + } + } + } diff --git a/poky/bitbake/doc/bitbake-user-manual/bitbake-user-manual-execution.xml b/poky/bitbake/doc/bitbake-user-manual/bitbake-user-manual-execution.xml index e4251dff5..04c5a26b9 100644 --- a/poky/bitbake/doc/bitbake-user-manual/bitbake-user-manual-execution.xml +++ b/poky/bitbake/doc/bitbake-user-manual/bitbake-user-manual-execution.xml @@ -765,7 +765,7 @@ the concept: <literallayout class='monospaced'> BB_HASHBASE_WHITELIST ?= "TMPDIR FILE PATH PWD BB_TASKHASH BBPATH DL_DIR \ - SSTATE_DIR THISDIR FILESEXTRAPATHS FILE_DIRNAME HOME LOGNAME SHELL TERM \ + SSTATE_DIR THISDIR FILESEXTRAPATHS FILE_DIRNAME HOME LOGNAME SHELL \ USER FILESPATH STAGING_DIR_HOST STAGING_DIR_TARGET COREBASE PRSERV_HOST \ PRSERV_DUMPDIR PRSERV_DUMPFILE PRSERV_LOCKDOWN PARALLEL_MAKE \ CCACHE_DIR EXTERNAL_TOOLCHAIN CCACHE CCACHE_DISABLE LICENSE_PATH SDKPKGSUFFIX" diff --git a/poky/bitbake/doc/bitbake-user-manual/bitbake-user-manual-fetching.rst b/poky/bitbake/doc/bitbake-user-manual/bitbake-user-manual-fetching.rst new file mode 100644 index 000000000..f62ddffe8 --- /dev/null +++ b/poky/bitbake/doc/bitbake-user-manual/bitbake-user-manual-fetching.rst @@ -0,0 +1,652 @@ +.. SPDX-License-Identifier: CC-BY-2.5 + +===================== +File Download Support +===================== + +| + +BitBake's fetch module is a standalone piece of library code that deals +with the intricacies of downloading source code and files from remote +systems. Fetching source code is one of the cornerstones of building +software. As such, this module forms an important part of BitBake. + +The current fetch module is called "fetch2" and refers to the fact that +it is the second major version of the API. The original version is +obsolete and has been removed from the codebase. Thus, in all cases, +"fetch" refers to "fetch2" in this manual. + +The Download (Fetch) +==================== + +BitBake takes several steps when fetching source code or files. The +fetcher codebase deals with two distinct processes in order: obtaining +the files from somewhere (cached or otherwise) and then unpacking those +files into a specific location and perhaps in a specific way. Getting +and unpacking the files is often optionally followed by patching. +Patching, however, is not covered by this module. + +The code to execute the first part of this process, a fetch, looks +something like the following: :: + + src_uri = (d.getVar('SRC_URI') or "").split() + fetcher = bb.fetch2.Fetch(src_uri, d) + fetcher.download() + +This code sets up an instance of the fetch class. The instance uses a +space-separated list of URLs from the :term:`SRC_URI` +variable and then calls the ``download`` method to download the files. + +The instantiation of the fetch class is usually followed by: :: + + rootdir = l.getVar('WORKDIR') + fetcher.unpack(rootdir) + +This code unpacks the downloaded files to the specified by ``WORKDIR``. + +.. note:: + + For convenience, the naming in these examples matches the variables + used by OpenEmbedded. If you want to see the above code in action, + examine the OpenEmbedded class file ``base.bbclass`` + . + +The ``SRC_URI`` and ``WORKDIR`` variables are not hardcoded into the +fetcher, since those fetcher methods can be (and are) called with +different variable names. In OpenEmbedded for example, the shared state +(sstate) code uses the fetch module to fetch the sstate files. + +When the ``download()`` method is called, BitBake tries to resolve the +URLs by looking for source files in a specific search order: + +- *Pre-mirror Sites:* BitBake first uses pre-mirrors to try and find + source files. These locations are defined using the + :term:`PREMIRRORS` variable. + +- *Source URI:* If pre-mirrors fail, BitBake uses the original URL (e.g + from ``SRC_URI``). + +- *Mirror Sites:* If fetch failures occur, BitBake next uses mirror + locations as defined by the :term:`MIRRORS` variable. + +For each URL passed to the fetcher, the fetcher calls the submodule that +handles that particular URL type. This behavior can be the source of +some confusion when you are providing URLs for the ``SRC_URI`` variable. +Consider the following two URLs: :: + + http://git.yoctoproject.org/git/poky;protocol=git + git://git.yoctoproject.org/git/poky;protocol=http + +In the former case, the URL is passed to the ``wget`` fetcher, which does not +understand "git". Therefore, the latter case is the correct form since the Git +fetcher does know how to use HTTP as a transport. + +Here are some examples that show commonly used mirror definitions: :: + + PREMIRRORS ?= "\ + bzr://.*/.\* http://somemirror.org/sources/ \\n \ + cvs://.*/.\* http://somemirror.org/sources/ \\n \ + git://.*/.\* http://somemirror.org/sources/ \\n \ + hg://.*/.\* http://somemirror.org/sources/ \\n \ + osc://.*/.\* http://somemirror.org/sources/ \\n \ + p4://.*/.\* http://somemirror.org/sources/ \\n \ + svn://.*/.\* http://somemirror.org/sources/ \\n" + + MIRRORS =+ "\ + ftp://.*/.\* http://somemirror.org/sources/ \\n \ + http://.*/.\* http://somemirror.org/sources/ \\n \ + https://.*/.\* http://somemirror.org/sources/ \\n" + +It is useful to note that BitBake +supports cross-URLs. It is possible to mirror a Git repository on an +HTTP server as a tarball. This is what the ``git://`` mapping in the +previous example does. + +Since network accesses are slow, BitBake maintains a cache of files +downloaded from the network. Any source files that are not local (i.e. +downloaded from the Internet) are placed into the download directory, +which is specified by the :term:`DL_DIR` variable. + +File integrity is of key importance for reproducing builds. For +non-local archive downloads, the fetcher code can verify SHA-256 and MD5 +checksums to ensure the archives have been downloaded correctly. You can +specify these checksums by using the ``SRC_URI`` variable with the +appropriate varflags as follows: :: + + SRC_URI[md5sum] = "value" + SRC_URI[sha256sum] = "value" + +You can also specify the checksums as +parameters on the ``SRC_URI`` as shown below: :: + + SRC_URI = "http://example.com/foobar.tar.bz2;md5sum=4a8e0f237e961fd7785d19d07fdb994d" + +If multiple URIs exist, you can specify the checksums either directly as +in the previous example, or you can name the URLs. The following syntax +shows how you name the URIs: :: + + SRC_URI = "http://example.com/foobar.tar.bz2;name=foo" + SRC_URI[foo.md5sum] = 4a8e0f237e961fd7785d19d07fdb994d + +After a file has been downloaded and +has had its checksum checked, a ".done" stamp is placed in ``DL_DIR``. +BitBake uses this stamp during subsequent builds to avoid downloading or +comparing a checksum for the file again. + +.. note:: + + It is assumed that local storage is safe from data corruption. If + this were not the case, there would be bigger issues to worry about. + +If :term:`BB_STRICT_CHECKSUM` is set, any +download without a checksum triggers an error message. The +:term:`BB_NO_NETWORK` variable can be used to +make any attempted network access a fatal error, which is useful for +checking that mirrors are complete as well as other things. + +.. _bb-the-unpack: + +The Unpack +========== + +The unpack process usually immediately follows the download. For all +URLs except Git URLs, BitBake uses the common ``unpack`` method. + +A number of parameters exist that you can specify within the URL to +govern the behavior of the unpack stage: + +- *unpack:* Controls whether the URL components are unpacked. If set to + "1", which is the default, the components are unpacked. If set to + "0", the unpack stage leaves the file alone. This parameter is useful + when you want an archive to be copied in and not be unpacked. + +- *dos:* Applies to ``.zip`` and ``.jar`` files and specifies whether + to use DOS line ending conversion on text files. + +- *basepath:* Instructs the unpack stage to strip the specified + directories from the source path when unpacking. + +- *subdir:* Unpacks the specific URL to the specified subdirectory + within the root directory. + +The unpack call automatically decompresses and extracts files with ".Z", +".z", ".gz", ".xz", ".zip", ".jar", ".ipk", ".rpm". ".srpm", ".deb" and +".bz2" extensions as well as various combinations of tarball extensions. + +As mentioned, the Git fetcher has its own unpack method that is +optimized to work with Git trees. Basically, this method works by +cloning the tree into the final directory. The process is completed +using references so that there is only one central copy of the Git +metadata needed. + +.. _bb-fetchers: + +Fetchers +======== + +As mentioned earlier, the URL prefix determines which fetcher submodule +BitBake uses. Each submodule can support different URL parameters, which +are described in the following sections. + +.. _local-file-fetcher: + +Local file fetcher (``file://``) +-------------------------------- + +This submodule handles URLs that begin with ``file://``. The filename +you specify within the URL can be either an absolute or relative path to +a file. If the filename is relative, the contents of the +:term:`FILESPATH` variable is used in the same way +``PATH`` is used to find executables. If the file cannot be found, it is +assumed that it is available in :term:`DL_DIR` by the +time the ``download()`` method is called. + +If you specify a directory, the entire directory is unpacked. + +Here are a couple of example URLs, the first relative and the second +absolute: :: + + SRC_URI = "file://relativefile.patch" + SRC_URI = "file:///Users/ich/very_important_software" + +.. _http-ftp-fetcher: + +HTTP/FTP wget fetcher (``http://``, ``ftp://``, ``https://``) +------------------------------------------------------------- + +This fetcher obtains files from web and FTP servers. Internally, the +fetcher uses the wget utility. + +The executable and parameters used are specified by the +``FETCHCMD_wget`` variable, which defaults to sensible values. The +fetcher supports a parameter "downloadfilename" that allows the name of +the downloaded file to be specified. Specifying the name of the +downloaded file is useful for avoiding collisions in +:term:`DL_DIR` when dealing with multiple files that +have the same name. + +Some example URLs are as follows: :: + + SRC_URI = "http://oe.handhelds.org/not_there.aac" + SRC_URI = "ftp://oe.handhelds.org/not_there_as_well.aac" + SRC_URI = "ftp://you@oe.handhelds.org/home/you/secret.plan" + +.. note:: + + Because URL parameters are delimited by semi-colons, this can + introduce ambiguity when parsing URLs that also contain semi-colons, + for example: + :: + + SRC_URI = "http://abc123.org/git/?p=gcc/gcc.git;a=snapshot;h=a5dd47" + + + Such URLs should should be modified by replacing semi-colons with '&' + characters: + :: + + SRC_URI = "http://abc123.org/git/?p=gcc/gcc.git&a=snapshot&h=a5dd47" + + + In most cases this should work. Treating semi-colons and '&' in + queries identically is recommended by the World Wide Web Consortium + (W3C). Note that due to the nature of the URL, you may have to + specify the name of the downloaded file as well: + :: + + SRC_URI = "http://abc123.org/git/?p=gcc/gcc.git&a=snapshot&h=a5dd47;downloadfilename=myfile.bz2" + + +.. _cvs-fetcher: + +CVS fetcher (``(cvs://``) +------------------------- + +This submodule handles checking out files from the CVS version control +system. You can configure it using a number of different variables: + +- :term:`FETCHCMD_cvs <FETCHCMD>`: The name of the executable to use when running + the ``cvs`` command. This name is usually "cvs". + +- :term:`SRCDATE`: The date to use when fetching the CVS source code. A + special value of "now" causes the checkout to be updated on every + build. + +- :term:`CVSDIR`: Specifies where a temporary + checkout is saved. The location is often ``DL_DIR/cvs``. + +- CVS_PROXY_HOST: The name to use as a "proxy=" parameter to the + ``cvs`` command. + +- CVS_PROXY_PORT: The port number to use as a "proxyport=" + parameter to the ``cvs`` command. + +As well as the standard username and password URL syntax, you can also +configure the fetcher with various URL parameters: + +The supported parameters are as follows: + +- *"method":* The protocol over which to communicate with the CVS + server. By default, this protocol is "pserver". If "method" is set to + "ext", BitBake examines the "rsh" parameter and sets ``CVS_RSH``. You + can use "dir" for local directories. + +- *"module":* Specifies the module to check out. You must supply this + parameter. + +- *"tag":* Describes which CVS TAG should be used for the checkout. By + default, the TAG is empty. + +- *"date":* Specifies a date. If no "date" is specified, the + :term:`SRCDATE` of the configuration is used to + checkout a specific date. The special value of "now" causes the + checkout to be updated on every build. + +- *"localdir":* Used to rename the module. Effectively, you are + renaming the output directory to which the module is unpacked. You + are forcing the module into a special directory relative to + :term:`CVSDIR`. + +- *"rsh":* Used in conjunction with the "method" parameter. + +- *"scmdata":* Causes the CVS metadata to be maintained in the tarball + the fetcher creates when set to "keep". The tarball is expanded into + the work directory. By default, the CVS metadata is removed. + +- *"fullpath":* Controls whether the resulting checkout is at the + module level, which is the default, or is at deeper paths. + +- *"norecurse":* Causes the fetcher to only checkout the specified + directory with no recurse into any subdirectories. + +- *"port":* The port to which the CVS server connects. + +Some example URLs are as follows: :: + + SRC_URI = "cvs://CVSROOT;module=mymodule;tag=some-version;method=ext" + SRC_URI = "cvs://CVSROOT;module=mymodule;date=20060126;localdir=usethat" + +.. _svn-fetcher: + +Subversion (SVN) Fetcher (``svn://``) +------------------------------------- + +This fetcher submodule fetches code from the Subversion source control +system. The executable used is specified by ``FETCHCMD_svn``, which +defaults to "svn". The fetcher's temporary working directory is set by +:term:`SVNDIR`, which is usually ``DL_DIR/svn``. + +The supported parameters are as follows: + +- *"module":* The name of the svn module to checkout. You must provide + this parameter. You can think of this parameter as the top-level + directory of the repository data you want. + +- *"path_spec":* A specific directory in which to checkout the + specified svn module. + +- *"protocol":* The protocol to use, which defaults to "svn". If + "protocol" is set to "svn+ssh", the "ssh" parameter is also used. + +- *"rev":* The revision of the source code to checkout. + +- *"scmdata":* Causes the “.svn” directories to be available during + compile-time when set to "keep". By default, these directories are + removed. + +- *"ssh":* An optional parameter used when "protocol" is set to + "svn+ssh". You can use this parameter to specify the ssh program used + by svn. + +- *"transportuser":* When required, sets the username for the + transport. By default, this parameter is empty. The transport + username is different than the username used in the main URL, which + is passed to the subversion command. + +Following are three examples using svn: :: + + SRC_URI = "svn://myrepos/proj1;module=vip;protocol=http;rev=667" + SRC_URI = "svn://myrepos/proj1;module=opie;protocol=svn+ssh" + SRC_URI = "svn://myrepos/proj1;module=trunk;protocol=http;path_spec=${MY_DIR}/proj1" + +.. _git-fetcher: + +Git Fetcher (``git://``) +------------------------ + +This fetcher submodule fetches code from the Git source control system. +The fetcher works by creating a bare clone of the remote into +:term:`GITDIR`, which is usually ``DL_DIR/git2``. This +bare clone is then cloned into the work directory during the unpack +stage when a specific tree is checked out. This is done using alternates +and by reference to minimize the amount of duplicate data on the disk +and make the unpack process fast. The executable used can be set with +``FETCHCMD_git``. + +This fetcher supports the following parameters: + +- *"protocol":* The protocol used to fetch the files. The default is + "git" when a hostname is set. If a hostname is not set, the Git + protocol is "file". You can also use "http", "https", "ssh" and + "rsync". + +- *"nocheckout":* Tells the fetcher to not checkout source code when + unpacking when set to "1". Set this option for the URL where there is + a custom routine to checkout code. The default is "0". + +- *"rebaseable":* Indicates that the upstream Git repository can be + rebased. You should set this parameter to "1" if revisions can become + detached from branches. In this case, the source mirror tarball is + done per revision, which has a loss of efficiency. Rebasing the + upstream Git repository could cause the current revision to disappear + from the upstream repository. This option reminds the fetcher to + preserve the local cache carefully for future use. The default value + for this parameter is "0". + +- *"nobranch":* Tells the fetcher to not check the SHA validation for + the branch when set to "1". The default is "0". Set this option for + the recipe that refers to the commit that is valid for a tag instead + of the branch. + +- *"bareclone":* Tells the fetcher to clone a bare clone into the + destination directory without checking out a working tree. Only the + raw Git metadata is provided. This parameter implies the "nocheckout" + parameter as well. + +- *"branch":* The branch(es) of the Git tree to clone. If unset, this + is assumed to be "master". The number of branch parameters much match + the number of name parameters. + +- *"rev":* The revision to use for the checkout. The default is + "master". + +- *"tag":* Specifies a tag to use for the checkout. To correctly + resolve tags, BitBake must access the network. For that reason, tags + are often not used. As far as Git is concerned, the "tag" parameter + behaves effectively the same as the "rev" parameter. + +- *"subpath":* Limits the checkout to a specific subpath of the tree. + By default, the whole tree is checked out. + +- *"destsuffix":* The name of the path in which to place the checkout. + By default, the path is ``git/``. + +- *"usehead":* Enables local ``git://`` URLs to use the current branch + HEAD as the revision for use with ``AUTOREV``. The "usehead" + parameter implies no branch and only works when the transfer protocol + is ``file://``. + +Here are some example URLs: :: + + SRC_URI = "git://git.oe.handhelds.org/git/vip.git;tag=version-1" + SRC_URI = "git://git.oe.handhelds.org/git/vip.git;protocol=http" + +.. _gitsm-fetcher: + +Git Submodule Fetcher (``gitsm://``) +------------------------------------ + +This fetcher submodule inherits from the :ref:`Git +fetcher<bitbake-user-manual/bitbake-user-manual-fetching:git fetcher +(\`\`git://\`\`)>` and extends that fetcher's behavior by fetching a +repository's submodules. :term:`SRC_URI` is passed to the Git fetcher as +described in the :ref:`bitbake-user-manual/bitbake-user-manual-fetching:git +fetcher (\`\`git://\`\`)` section. + +.. note:: + + You must clean a recipe when switching between '``git://``' and + '``gitsm://``' URLs. + + The Git Submodules fetcher is not a complete fetcher implementation. + The fetcher has known issues where it does not use the normal source + mirroring infrastructure properly. Further, the submodule sources it + fetches are not visible to the licensing and source archiving + infrastructures. + +.. _clearcase-fetcher: + +ClearCase Fetcher (``ccrc://``) +------------------------------- + +This fetcher submodule fetches code from a +`ClearCase <http://en.wikipedia.org/wiki/Rational_ClearCase>`__ +repository. + +To use this fetcher, make sure your recipe has proper +:term:`SRC_URI`, :term:`SRCREV`, and +:term:`PV` settings. Here is an example: :: + + SRC_URI = "ccrc://cc.example.org/ccrc;vob=/example_vob;module=/example_module" + SRCREV = "EXAMPLE_CLEARCASE_TAG" + PV = "${@d.getVar("SRCREV", False).replace("/", "+")}" + +The fetcher uses the ``rcleartool`` or +``cleartool`` remote client, depending on which one is available. + +Following are options for the ``SRC_URI`` statement: + +- *vob*: The name, which must include the prepending "/" character, + of the ClearCase VOB. This option is required. + +- *module*: The module, which must include the prepending "/" + character, in the selected VOB. + + .. note:: + + The module and vob options are combined to create the load rule in the + view config spec. As an example, consider the vob and module values from + the SRC_URI statement at the start of this section. Combining those values + results in the following: :: + + load /example_vob/example_module + +- *proto*: The protocol, which can be either ``http`` or ``https``. + +By default, the fetcher creates a configuration specification. If you +want this specification written to an area other than the default, use +the ``CCASE_CUSTOM_CONFIG_SPEC`` variable in your recipe to define where +the specification is written. + +.. note:: + + the SRCREV loses its functionality if you specify this variable. However, + SRCREV is still used to label the archive after a fetch even though it does + not define what is fetched. + +Here are a couple of other behaviors worth mentioning: + +- When using ``cleartool``, the login of ``cleartool`` is handled by + the system. The login require no special steps. + +- In order to use ``rcleartool`` with authenticated users, an + "rcleartool login" is necessary before using the fetcher. + +.. _perforce-fetcher: + +Perforce Fetcher (``p4://``) +---------------------------- + +This fetcher submodule fetches code from the +`Perforce <https://www.perforce.com/>`__ source control system. The +executable used is specified by ``FETCHCMD_p4``, which defaults to "p4". +The fetcher's temporary working directory is set by +:term:`P4DIR`, which defaults to "DL_DIR/p4". +The fetcher does not make use of a perforce client, instead it +relies on ``p4 files`` to retrieve a list of +files and ``p4 print`` to transfer the content +of those files locally. + +To use this fetcher, make sure your recipe has proper +:term:`SRC_URI`, :term:`SRCREV`, and +:term:`PV` values. The p4 executable is able to use the +config file defined by your system's ``P4CONFIG`` environment variable +in order to define the Perforce server URL and port, username, and +password if you do not wish to keep those values in a recipe itself. If +you choose not to use ``P4CONFIG``, or to explicitly set variables that +``P4CONFIG`` can contain, you can specify the ``P4PORT`` value, which is +the server's URL and port number, and you can specify a username and +password directly in your recipe within ``SRC_URI``. + +Here is an example that relies on ``P4CONFIG`` to specify the server URL +and port, username, and password, and fetches the Head Revision: :: + + SRC_URI = "p4://example-depot/main/source/..." + SRCREV = "${AUTOREV}" + PV = "p4-${SRCPV}" + S = "${WORKDIR}/p4" + +Here is an example that specifies the server URL and port, username, and +password, and fetches a Revision based on a Label: :: + + P4PORT = "tcp:p4server.example.net:1666" + SRC_URI = "p4://user:passwd@example-depot/main/source/..." + SRCREV = "release-1.0" + PV = "p4-${SRCPV}" + S = "${WORKDIR}/p4" + +.. note:: + + You should always set S to "${WORKDIR}/p4" in your recipe. + +By default, the fetcher strips the depot location from the local file paths. In +the above example, the content of ``example-depot/main/source/`` will be placed +in ``${WORKDIR}/p4``. For situations where preserving parts of the remote depot +paths locally is desirable, the fetcher supports two parameters: + +- *"module":* + The top-level depot location or directory to fetch. The value of this + parameter can also point to a single file within the depot, in which case + the local file path will include the module path. +- *"remotepath":* + When used with the value "``keep``", the fetcher will mirror the full depot + paths locally for the specified location, even in combination with the + ``module`` parameter. + +Here is an example use of the the ``module`` parameter: :: + + SRC_URI = "p4://user:passwd@example-depot/main;module=source/..." + +In this case, the content of the top-level directory ``source/`` will be fetched +to ``${P4DIR}``, including the directory itself. The top-level directory will +be accesible at ``${P4DIR}/source/``. + +Here is an example use of the the ``remotepath`` parameter: :: + + SRC_URI = "p4://user:passwd@example-depot/main;module=source/...;remotepath=keep" + +In this case, the content of the top-level directory ``source/`` will be fetched +to ``${P4DIR}``, but the complete depot paths will be mirrored locally. The +top-level directory will be accessible at +``${P4DIR}/example-depot/main/source/``. + +.. _repo-fetcher: + +Repo Fetcher (``repo://``) +-------------------------- + +This fetcher submodule fetches code from ``google-repo`` source control +system. The fetcher works by initiating and syncing sources of the +repository into :term:`REPODIR`, which is usually +``${DL_DIR}/repo``. + +This fetcher supports the following parameters: + +- *"protocol":* Protocol to fetch the repository manifest (default: + git). + +- *"branch":* Branch or tag of repository to get (default: master). + +- *"manifest":* Name of the manifest file (default: ``default.xml``). + +Here are some example URLs: :: + + SRC_URI = "repo://REPOROOT;protocol=git;branch=some_branch;manifest=my_manifest.xml" + SRC_URI = "repo://REPOROOT;protocol=file;branch=some_branch;manifest=my_manifest.xml" + +Other Fetchers +-------------- + +Fetch submodules also exist for the following: + +- Bazaar (``bzr://``) + +- Mercurial (``hg://``) + +- npm (``npm://``) + +- OSC (``osc://``) + +- Secure FTP (``sftp://``) + +- Secure Shell (``ssh://``) + +- Trees using Git Annex (``gitannex://``) + +No documentation currently exists for these lesser used fetcher +submodules. However, you might find the code helpful and readable. + +Auto Revisions +============== + +We need to document ``AUTOREV`` and ``SRCREV_FORMAT`` here. diff --git a/poky/bitbake/doc/bitbake-user-manual/bitbake-user-manual-fetching.xml b/poky/bitbake/doc/bitbake-user-manual/bitbake-user-manual-fetching.xml index d1bfc2336..fe4372ade 100644 --- a/poky/bitbake/doc/bitbake-user-manual/bitbake-user-manual-fetching.xml +++ b/poky/bitbake/doc/bitbake-user-manual/bitbake-user-manual-fetching.xml @@ -736,6 +736,10 @@ The fetcher's temporary working directory is set by <link linkend='var-bb-P4DIR'><filename>P4DIR</filename></link>, which defaults to "DL_DIR/p4". + The fetcher does not make use of a perforce client, instead it + relies on <filename>p4 files</filename> to retrieve a list of + files and <filename>p4 print</filename> to transfer the content + of those files locally. </para> <para> @@ -783,6 +787,62 @@ to <filename>"${WORKDIR}/p4"</filename> in your recipe. </note> </para> + + <para> + By default, the fetcher strips the depot location from the + local file paths. In the above example, the content of + <filename>example-depot/main/source/</filename> + will be placed in <filename>${WORKDIR}/p4</filename>. + For situations where preserving parts of the remote depot paths + locally is desirable, the fetcher supports two parameters: + + <itemizedlist> + <listitem><para> + <emphasis>"module":</emphasis> + The top-level depot location or directory to fetch. The + value of this parameter can also point to a single file + within the depot, in which case the local file path will + include the module path. + </para></listitem> + <listitem><para> + <emphasis>"remotepath":</emphasis> + When used with the value "<filename>keep</filename>", + the fetcher will mirror the full depot paths locally + for the specified location, even in combination with + the <filename>module</filename> parameter. + </para></listitem> + </itemizedlist> + </para> + + <para> + Here is an example use of the the <filename>module</filename> + parameter: + + <literallayout class='monospaced'> + SRC_URI = "p4://user:passwd@example-depot/main;module=source/..." + </literallayout> + + In this case, the content of the top-level directory + <filename>source/</filename> will be fetched to + <filename>${P4DIR}</filename>, including the directory itself. + The top-level directory will be accesible at + <filename>${P4DIR}/source/</filename>. + </para> + + <para> + Here is an example use of the the <filename>remotepath</filename> + parameter: + + <literallayout class='monospaced'> + SRC_URI = "p4://user:passwd@example-depot/main;module=source/...;remotepath=keep" + </literallayout> + + In this case, the content of the top-level directory + <filename>source/</filename> will be fetched to + <filename>${P4DIR}</filename>, but the complete depot paths will + be mirrored locally. The top-level directory will be accessible + at <filename>${P4DIR}/example-depot/main/source/</filename>. + </para> </section> <section id='repo-fetcher'> diff --git a/poky/bitbake/doc/bitbake-user-manual/bitbake-user-manual-hello.rst b/poky/bitbake/doc/bitbake-user-manual/bitbake-user-manual-hello.rst new file mode 100644 index 000000000..e3fd32158 --- /dev/null +++ b/poky/bitbake/doc/bitbake-user-manual/bitbake-user-manual-hello.rst @@ -0,0 +1,415 @@ +.. SPDX-License-Identifier: CC-BY-2.5 + +=================== +Hello World Example +=================== + +BitBake Hello World +=================== + +The simplest example commonly used to demonstrate any new programming +language or tool is the "`Hello +World <http://en.wikipedia.org/wiki/Hello_world_program>`__" example. +This appendix demonstrates, in tutorial form, Hello World within the +context of BitBake. The tutorial describes how to create a new project +and the applicable metadata files necessary to allow BitBake to build +it. + +Obtaining BitBake +================= + +See the :ref:`bitbake-user-manual/bitbake-user-manual-hello:obtaining bitbake` section for +information on how to obtain BitBake. Once you have the source code on +your machine, the BitBake directory appears as follows: :: + + $ ls -al + total 100 + drwxrwxr-x. 9 wmat wmat 4096 Jan 31 13:44 . + drwxrwxr-x. 3 wmat wmat 4096 Feb 4 10:45 .. + -rw-rw-r--. 1 wmat wmat 365 Nov 26 04:55 AUTHORS + drwxrwxr-x. 2 wmat wmat 4096 Nov 26 04:55 bin + drwxrwxr-x. 4 wmat wmat 4096 Jan 31 13:44 build + -rw-rw-r--. 1 wmat wmat 16501 Nov 26 04:55 ChangeLog + drwxrwxr-x. 2 wmat wmat 4096 Nov 26 04:55 classes + drwxrwxr-x. 2 wmat wmat 4096 Nov 26 04:55 conf + drwxrwxr-x. 3 wmat wmat 4096 Nov 26 04:55 contrib + -rw-rw-r--. 1 wmat wmat 17987 Nov 26 04:55 COPYING + drwxrwxr-x. 3 wmat wmat 4096 Nov 26 04:55 doc + -rw-rw-r--. 1 wmat wmat 69 Nov 26 04:55 .gitignore + -rw-rw-r--. 1 wmat wmat 849 Nov 26 04:55 HEADER + drwxrwxr-x. 5 wmat wmat 4096 Jan 31 13:44 lib + -rw-rw-r--. 1 wmat wmat 195 Nov 26 04:55 MANIFEST.in + -rw-rw-r--. 1 wmat wmat 2887 Nov 26 04:55 TODO + +At this point, you should have BitBake cloned to a directory that +matches the previous listing except for dates and user names. + +Setting Up the BitBake Environment +================================== + +First, you need to be sure that you can run BitBake. Set your working +directory to where your local BitBake files are and run the following +command: :: + + $ ./bin/bitbake --version + BitBake Build Tool Core version 1.23.0, bitbake version 1.23.0 + +The console output tells you what version +you are running. + +The recommended method to run BitBake is from a directory of your +choice. To be able to run BitBake from any directory, you need to add +the executable binary to your binary to your shell's environment +``PATH`` variable. First, look at your current ``PATH`` variable by +entering the following: :: + + $ echo $PATH + +Next, add the directory location +for the BitBake binary to the ``PATH``. Here is an example that adds the +``/home/scott-lenovo/bitbake/bin`` directory to the front of the +``PATH`` variable: :: + + $ export PATH=/home/scott-lenovo/bitbake/bin:$PATH + +You should now be able to enter the ``bitbake`` command from the command +line while working from any directory. + +The Hello World Example +======================= + +The overall goal of this exercise is to build a complete "Hello World" +example utilizing task and layer concepts. Because this is how modern +projects such as OpenEmbedded and the Yocto Project utilize BitBake, the +example provides an excellent starting point for understanding BitBake. + +To help you understand how to use BitBake to build targets, the example +starts with nothing but the ``bitbake`` command, which causes BitBake to +fail and report problems. The example progresses by adding pieces to the +build to eventually conclude with a working, minimal "Hello World" +example. + +While every attempt is made to explain what is happening during the +example, the descriptions cannot cover everything. You can find further +information throughout this manual. Also, you can actively participate +in the :oe_lists:`/g/bitbake-devel` +discussion mailing list about the BitBake build tool. + +.. note:: + + This example was inspired by and drew heavily from + `Mailing List post - The BitBake equivalent of "Hello, World!" + <http://www.mail-archive.com/yocto@yoctoproject.org/msg09379.html>`_. + +As stated earlier, the goal of this example is to eventually compile +"Hello World". However, it is unknown what BitBake needs and what you +have to provide in order to achieve that goal. Recall that BitBake +utilizes three types of metadata files: +:ref:`bitbake-user-manual/bitbake-user-manual-intro:configuration files`, +:ref:`bitbake-user-manual/bitbake-user-manual-intro:classes`, and +:ref:`bitbake-user-manual/bitbake-user-manual-intro:recipes`. +But where do they go? How does BitBake find +them? BitBake's error messaging helps you answer these types of +questions and helps you better understand exactly what is going on. + +Following is the complete "Hello World" example. + +#. **Create a Project Directory:** First, set up a directory for the + "Hello World" project. Here is how you can do so in your home + directory: :: + + $ mkdir ~/hello + $ cd ~/hello + + This is the directory that + BitBake will use to do all of its work. You can use this directory + to keep all the metafiles needed by BitBake. Having a project + directory is a good way to isolate your project. + +#. **Run BitBake:** At this point, you have nothing but a project + directory. Run the ``bitbake`` command and see what it does: :: + + $ bitbake + The BBPATH variable is not set and bitbake did not + find a conf/bblayers.conf file in the expected location. + Maybe you accidentally invoked bitbake from the wrong directory? + DEBUG: Removed the following variables from the environment: + GNOME_DESKTOP_SESSION_ID, XDG_CURRENT_DESKTOP, + GNOME_KEYRING_CONTROL, DISPLAY, SSH_AGENT_PID, LANG, no_proxy, + XDG_SESSION_PATH, XAUTHORITY, SESSION_MANAGER, SHLVL, + MANDATORY_PATH, COMPIZ_CONFIG_PROFILE, WINDOWID, EDITOR, + GPG_AGENT_INFO, SSH_AUTH_SOCK, GDMSESSION, GNOME_KEYRING_PID, + XDG_SEAT_PATH, XDG_CONFIG_DIRS, LESSOPEN, DBUS_SESSION_BUS_ADDRESS, + _, XDG_SESSION_COOKIE, DESKTOP_SESSION, LESSCLOSE, DEFAULTS_PATH, + UBUNTU_MENUPROXY, OLDPWD, XDG_DATA_DIRS, COLORTERM, LS_COLORS + + The majority of this output is specific to environment variables that + are not directly relevant to BitBake. However, the very first + message regarding the ``BBPATH`` variable and the + ``conf/bblayers.conf`` file is relevant. + + When you run BitBake, it begins looking for metadata files. The + :term:`BBPATH` variable is what tells BitBake where + to look for those files. ``BBPATH`` is not set and you need to set + it. Without ``BBPATH``, BitBake cannot find any configuration files + (``.conf``) or recipe files (``.bb``) at all. BitBake also cannot + find the ``bitbake.conf`` file. + +#. **Setting BBPATH:** For this example, you can set ``BBPATH`` in + the same manner that you set ``PATH`` earlier in the appendix. You + should realize, though, that it is much more flexible to set the + ``BBPATH`` variable up in a configuration file for each project. + + From your shell, enter the following commands to set and export the + ``BBPATH`` variable: :: + + $ BBPATH="projectdirectory" + $ export BBPATH + + Use your actual project directory in the command. BitBake uses that + directory to find the metadata it needs for your project. + + .. note:: + + When specifying your project directory, do not use the tilde + ("~") character as BitBake does not expand that character as the + shell would. + +#. **Run BitBake:** Now that you have ``BBPATH`` defined, run the + ``bitbake`` command again: :: + + $ bitbake + ERROR: Traceback (most recent call last): + File "/home/scott-lenovo/bitbake/lib/bb/cookerdata.py", line 163, in wrapped + return func(fn, *args) + File "/home/scott-lenovo/bitbake/lib/bb/cookerdata.py", line 173, in parse_config_file + return bb.parse.handle(fn, data, include) + File "/home/scott-lenovo/bitbake/lib/bb/parse/__init__.py", line 99, in handle + return h['handle'](fn, data, include) + File "/home/scott-lenovo/bitbake/lib/bb/parse/parse_py/ConfHandler.py", line 120, in handle + abs_fn = resolve_file(fn, data) + File "/home/scott-lenovo/bitbake/lib/bb/parse/__init__.py", line 117, in resolve_file + raise IOError("file %s not found in %s" % (fn, bbpath)) + IOError: file conf/bitbake.conf not found in /home/scott-lenovo/hello + + ERROR: Unable to parse conf/bitbake.conf: file conf/bitbake.conf not found in /home/scott-lenovo/hello + + This sample output shows that BitBake could not find the + ``conf/bitbake.conf`` file in the project directory. This file is + the first thing BitBake must find in order to build a target. And, + since the project directory for this example is empty, you need to + provide a ``conf/bitbake.conf`` file. + +#. **Creating conf/bitbake.conf:** The ``conf/bitbake.conf`` includes + a number of configuration variables BitBake uses for metadata and + recipe files. For this example, you need to create the file in your + project directory and define some key BitBake variables. For more + information on the ``bitbake.conf`` file, see + http://git.openembedded.org/bitbake/tree/conf/bitbake.conf. + + Use the following commands to create the ``conf`` directory in the + project directory: :: + + $ mkdir conf + + From within the ``conf`` directory, + use some editor to create the ``bitbake.conf`` so that it contains + the following: :: + + PN = "${@bb.parse.BBHandler.vars_from_file(d.getVar('FILE', False),d)[0] or 'defaultpkgname'}" + + TMPDIR = "${TOPDIR}/tmp" + CACHE = "${TMPDIR}/cache" + STAMP = "${TMPDIR}/${PN}/stamps" + T = "${TMPDIR}/${PN}/work" + B = "${TMPDIR}/${PN}" + + .. note:: + + Without a value for PN , the variables STAMP , T , and B , prevent more + than one recipe from working. You can fix this by either setting PN to + have a value similar to what OpenEmbedded and BitBake use in the default + bitbake.conf file (see previous example). Or, by manually updating each + recipe to set PN . You will also need to include PN as part of the STAMP + , T , and B variable definitions in the local.conf file. + + The ``TMPDIR`` variable establishes a directory that BitBake uses + for build output and intermediate files other than the cached + information used by the + :ref:`bitbake-user-manual/bitbake-user-manual-execution:setscene` + process. Here, the ``TMPDIR`` directory is set to ``hello/tmp``. + + .. tip:: + + You can always safely delete the tmp directory in order to rebuild a + BitBake target. The build process creates the directory for you when you + run BitBake. + + For information about each of the other variables defined in this + example, check :term:`PN`, :term:`TOPDIR`, :term:`CACHE`, :term:`STAMP`, + :term:`T` or :term:`B` to take you to the definitions in the + glossary. + +#. **Run BitBake:** After making sure that the ``conf/bitbake.conf`` file + exists, you can run the ``bitbake`` command again: :: + + $ bitbake + ERROR: Traceback (most recent call last): + File "/home/scott-lenovo/bitbake/lib/bb/cookerdata.py", line 163, in wrapped + return func(fn, *args) + File "/home/scott-lenovo/bitbake/lib/bb/cookerdata.py", line 177, in _inherit + bb.parse.BBHandler.inherit(bbclass, "configuration INHERITs", 0, data) + File "/home/scott-lenovo/bitbake/lib/bb/parse/parse_py/BBHandler.py", line 92, in inherit + include(fn, file, lineno, d, "inherit") + File "/home/scott-lenovo/bitbake/lib/bb/parse/parse_py/ConfHandler.py", line 100, in include + raise ParseError("Could not %(error_out)s file %(fn)s" % vars(), oldfn, lineno) + ParseError: ParseError in configuration INHERITs: Could not inherit file classes/base.bbclass + + ERROR: Unable to parse base: ParseError in configuration INHERITs: Could not inherit file classes/base.bbclass + + In the sample output, + BitBake could not find the ``classes/base.bbclass`` file. You need + to create that file next. + +#. **Creating classes/base.bbclass:** BitBake uses class files to + provide common code and functionality. The minimally required class + for BitBake is the ``classes/base.bbclass`` file. The ``base`` class + is implicitly inherited by every recipe. BitBake looks for the class + in the ``classes`` directory of the project (i.e ``hello/classes`` + in this example). + + Create the ``classes`` directory as follows: :: + + $ cd $HOME/hello + $ mkdir classes + + Move to the ``classes`` directory and then create the + ``base.bbclass`` file by inserting this single line: addtask build + The minimal task that BitBake runs is the ``do_build`` task. This is + all the example needs in order to build the project. Of course, the + ``base.bbclass`` can have much more depending on which build + environments BitBake is supporting. + +#. **Run BitBake:** After making sure that the ``classes/base.bbclass`` + file exists, you can run the ``bitbake`` command again: :: + + $ bitbake + Nothing to do. Use 'bitbake world' to build everything, or run 'bitbake --help' for usage information. + + BitBake is finally reporting + no errors. However, you can see that it really does not have + anything to do. You need to create a recipe that gives BitBake + something to do. + +#. **Creating a Layer:** While it is not really necessary for such a + small example, it is good practice to create a layer in which to + keep your code separate from the general metadata used by BitBake. + Thus, this example creates and uses a layer called "mylayer". + + .. note:: + + You can find additional information on layers in the + ":ref:`bitbake-user-manual/bitbake-user-manual-intro:Layers`" section. + + Minimally, you need a recipe file and a layer configuration file in + your layer. The configuration file needs to be in the ``conf`` + directory inside the layer. Use these commands to set up the layer + and the ``conf`` directory: :: + + $ cd $HOME + $ mkdir mylayer + $ cd mylayer + $ mkdir conf + + Move to the ``conf`` directory and create a ``layer.conf`` file that has the + following: :: + + BBPATH .= ":${LAYERDIR}" + BBFILES += "${LAYERDIR}/\*.bb" + BBFILE_COLLECTIONS += "mylayer" + `BBFILE_PATTERN_mylayer := "^${LAYERDIR_RE}/" + + For information on these variables, click on :term:`BBFILES`, + :term:`LAYERDIR`, :term:`BBFILE_COLLECTIONS` or :term:`BBFILE_PATTERN_mylayer <BBFILE_PATTERN>` + to go to the definitions in the glossary. + + You need to create the recipe file next. Inside your layer at the + top-level, use an editor and create a recipe file named + ``printhello.bb`` that has the following: :: + + DESCRIPTION = "Prints Hello World" + PN = 'printhello' + PV = '1' + + python do_build() { + bb.plain("********************"); + bb.plain("* *"); + bb.plain("* Hello, World! *"); + bb.plain("* *"); + bb.plain("********************"); + } + + The recipe file simply provides + a description of the recipe, the name, version, and the ``do_build`` + task, which prints out "Hello World" to the console. For more + information on :term:`DESCRIPTION`, :term:`PN` or :term:`PV` + follow the links to the glossary. + +#. **Run BitBake With a Target:** Now that a BitBake target exists, run + the command and provide that target: :: + + $ cd $HOME/hello + $ bitbake printhello + ERROR: no recipe files to build, check your BBPATH and BBFILES? + + Summary: There was 1 ERROR message shown, returning a non-zero exit code. + + We have created the layer with the recipe and + the layer configuration file but it still seems that BitBake cannot + find the recipe. BitBake needs a ``conf/bblayers.conf`` that lists + the layers for the project. Without this file, BitBake cannot find + the recipe. + +#. **Creating conf/bblayers.conf:** BitBake uses the + ``conf/bblayers.conf`` file to locate layers needed for the project. + This file must reside in the ``conf`` directory of the project (i.e. + ``hello/conf`` for this example). + + Set your working directory to the ``hello/conf`` directory and then + create the ``bblayers.conf`` file so that it contains the following: :: + + BBLAYERS ?= " \ + /home/<you>/mylayer \ + " + + You need to provide your own information for ``you`` in the file. + +#. **Run BitBake With a Target:** Now that you have supplied the + ``bblayers.conf`` file, run the ``bitbake`` command and provide the + target: :: + + $ bitbake printhello + Parsing recipes: 100% |##################################################################################| + Time: 00:00:00 + Parsing of 1 .bb files complete (0 cached, 1 parsed). 1 targets, 0 skipped, 0 masked, 0 errors. + NOTE: Resolving any missing task queue dependencies + NOTE: Preparing RunQueue + NOTE: Executing RunQueue Tasks + ******************** + * * + * Hello, World! * + * * + ******************** + NOTE: Tasks Summary: Attempted 1 tasks of which 0 didn't need to be rerun and all succeeded. + + .. note:: + + After the first execution, re-running bitbake printhello again will not + result in a BitBake run that prints the same console output. The reason + for this is that the first time the printhello.bb recipe's do_build task + executes successfully, BitBake writes a stamp file for the task. Thus, + the next time you attempt to run the task using that same bitbake + command, BitBake notices the stamp and therefore determines that the task + does not need to be re-run. If you delete the tmp directory or run + bitbake -c clean printhello and then re-run the build, the "Hello, + World!" message will be printed again. diff --git a/poky/bitbake/doc/bitbake-user-manual/bitbake-user-manual-intro.rst b/poky/bitbake/doc/bitbake-user-manual/bitbake-user-manual-intro.rst new file mode 100644 index 000000000..77dc9668a --- /dev/null +++ b/poky/bitbake/doc/bitbake-user-manual/bitbake-user-manual-intro.rst @@ -0,0 +1,651 @@ +.. SPDX-License-Identifier: CC-BY-2.5 + +======== +Overview +======== + +| + +Welcome to the BitBake User Manual. This manual provides information on +the BitBake tool. The information attempts to be as independent as +possible regarding systems that use BitBake, such as OpenEmbedded and +the Yocto Project. In some cases, scenarios or examples within the +context of a build system are used in the manual to help with +understanding. For these cases, the manual clearly states the context. + +.. _intro: + +Introduction +============ + +Fundamentally, BitBake is a generic task execution engine that allows +shell and Python tasks to be run efficiently and in parallel while +working within complex inter-task dependency constraints. One of +BitBake's main users, OpenEmbedded, takes this core and builds embedded +Linux software stacks using a task-oriented approach. + +Conceptually, BitBake is similar to GNU Make in some regards but has +significant differences: + +- BitBake executes tasks according to provided metadata that builds up + the tasks. Metadata is stored in recipe (``.bb``) and related recipe + "append" (``.bbappend``) files, configuration (``.conf``) and + underlying include (``.inc``) files, and in class (``.bbclass``) + files. The metadata provides BitBake with instructions on what tasks + to run and the dependencies between those tasks. + +- BitBake includes a fetcher library for obtaining source code from + various places such as local files, source control systems, or + websites. + +- The instructions for each unit to be built (e.g. a piece of software) + are known as "recipe" files and contain all the information about the + unit (dependencies, source file locations, checksums, description and + so on). + +- BitBake includes a client/server abstraction and can be used from a + command line or used as a service over XML-RPC and has several + different user interfaces. + +History and Goals +================= + +BitBake was originally a part of the OpenEmbedded project. It was +inspired by the Portage package management system used by the Gentoo +Linux distribution. On December 7, 2004, OpenEmbedded project team +member Chris Larson split the project into two distinct pieces: + +- BitBake, a generic task executor + +- OpenEmbedded, a metadata set utilized by BitBake + +Today, BitBake is the primary basis of the +`OpenEmbedded <http://www.openembedded.org/>`__ project, which is being +used to build and maintain Linux distributions such as the `Angstrom +Distribution <http://www.angstrom-distribution.org/>`__, and which is +also being used as the build tool for Linux projects such as the `Yocto +Project <http://www.yoctoproject.org>`__. + +Prior to BitBake, no other build tool adequately met the needs of an +aspiring embedded Linux distribution. All of the build systems used by +traditional desktop Linux distributions lacked important functionality, +and none of the ad hoc Buildroot-based systems, prevalent in the +embedded space, were scalable or maintainable. + +Some important original goals for BitBake were: + +- Handle cross-compilation. + +- Handle inter-package dependencies (build time on target architecture, + build time on native architecture, and runtime). + +- Support running any number of tasks within a given package, + including, but not limited to, fetching upstream sources, unpacking + them, patching them, configuring them, and so forth. + +- Be Linux distribution agnostic for both build and target systems. + +- Be architecture agnostic. + +- Support multiple build and target operating systems (e.g. Cygwin, the + BSDs, and so forth). + +- Be self-contained, rather than tightly integrated into the build + machine's root filesystem. + +- Handle conditional metadata on the target architecture, operating + system, distribution, and machine. + +- Be easy to use the tools to supply local metadata and packages + against which to operate. + +- Be easy to use BitBake to collaborate between multiple projects for + their builds. + +- Provide an inheritance mechanism to share common metadata between + many packages. + +Over time it became apparent that some further requirements were +necessary: + +- Handle variants of a base recipe (e.g. native, sdk, and multilib). + +- Split metadata into layers and allow layers to enhance or override + other layers. + +- Allow representation of a given set of input variables to a task as a + checksum. Based on that checksum, allow acceleration of builds with + prebuilt components. + +BitBake satisfies all the original requirements and many more with +extensions being made to the basic functionality to reflect the +additional requirements. Flexibility and power have always been the +priorities. BitBake is highly extensible and supports embedded Python +code and execution of any arbitrary tasks. + +.. _Concepts: + +Concepts +======== + +BitBake is a program written in the Python language. At the highest +level, BitBake interprets metadata, decides what tasks are required to +run, and executes those tasks. Similar to GNU Make, BitBake controls how +software is built. GNU Make achieves its control through "makefiles", +while BitBake uses "recipes". + +BitBake extends the capabilities of a simple tool like GNU Make by +allowing for the definition of much more complex tasks, such as +assembling entire embedded Linux distributions. + +The remainder of this section introduces several concepts that should be +understood in order to better leverage the power of BitBake. + +Recipes +------- + +BitBake Recipes, which are denoted by the file extension ``.bb``, are +the most basic metadata files. These recipe files provide BitBake with +the following: + +- Descriptive information about the package (author, homepage, license, + and so on) + +- The version of the recipe + +- Existing dependencies (both build and runtime dependencies) + +- Where the source code resides and how to fetch it + +- Whether the source code requires any patches, where to find them, and + how to apply them + +- How to configure and compile the source code + +- How to assemble the generated artifacts into one or more installable + packages + +- Where on the target machine to install the package or packages + created + +Within the context of BitBake, or any project utilizing BitBake as its +build system, files with the ``.bb`` extension are referred to as +recipes. + +.. note:: + + The term "package" is also commonly used to describe recipes. + However, since the same word is used to describe packaged output from + a project, it is best to maintain a single descriptive term - + "recipes". Put another way, a single "recipe" file is quite capable + of generating a number of related but separately installable + "packages". In fact, that ability is fairly common. + +Configuration Files +------------------- + +Configuration files, which are denoted by the ``.conf`` extension, +define various configuration variables that govern the project's build +process. These files fall into several areas that define machine +configuration, distribution configuration, possible compiler tuning, +general common configuration, and user configuration. The main +configuration file is the sample ``bitbake.conf`` file, which is located +within the BitBake source tree ``conf`` directory. + +Classes +------- + +Class files, which are denoted by the ``.bbclass`` extension, contain +information that is useful to share between metadata files. The BitBake +source tree currently comes with one class metadata file called +``base.bbclass``. You can find this file in the ``classes`` directory. +The ``base.bbclass`` class files is special since it is always included +automatically for all recipes and classes. This class contains +definitions for standard basic tasks such as fetching, unpacking, +configuring (empty by default), compiling (runs any Makefile present), +installing (empty by default) and packaging (empty by default). These +tasks are often overridden or extended by other classes added during the +project development process. + +Layers +------ + +Layers allow you to isolate different types of customizations from each +other. While you might find it tempting to keep everything in one layer +when working on a single project, the more modular your metadata, the +easier it is to cope with future changes. + +To illustrate how you can use layers to keep things modular, consider +customizations you might make to support a specific target machine. +These types of customizations typically reside in a special layer, +rather than a general layer, called a Board Support Package (BSP) layer. +Furthermore, the machine customizations should be isolated from recipes +and metadata that support a new GUI environment, for example. This +situation gives you a couple of layers: one for the machine +configurations and one for the GUI environment. It is important to +understand, however, that the BSP layer can still make machine-specific +additions to recipes within the GUI environment layer without polluting +the GUI layer itself with those machine-specific changes. You can +accomplish this through a recipe that is a BitBake append +(``.bbappend``) file. + +.. _append-bbappend-files: + +Append Files +------------ + +Append files, which are files that have the ``.bbappend`` file +extension, extend or override information in an existing recipe file. + +BitBake expects every append file to have a corresponding recipe file. +Furthermore, the append file and corresponding recipe file must use the +same root filename. The filenames can differ only in the file type +suffix used (e.g. ``formfactor_0.0.bb`` and +``formfactor_0.0.bbappend``). + +Information in append files extends or overrides the information in the +underlying, similarly-named recipe files. + +When you name an append file, you can use the "``%``" wildcard character +to allow for matching recipe names. For example, suppose you have an +append file named as follows: :: + + busybox_1.21.%.bbappend + +That append file +would match any ``busybox_1.21.``\ x\ ``.bb`` version of the recipe. So, +the append file would match the following recipe names: :: + + busybox_1.21.1.bb + busybox_1.21.2.bb + busybox_1.21.3.bb + +.. note:: + + The use of the " % " character is limited in that it only works directly in + front of the .bbappend portion of the append file's name. You cannot use the + wildcard character in any other location of the name. + +If the ``busybox`` recipe was updated to ``busybox_1.3.0.bb``, the +append name would not match. However, if you named the append file +``busybox_1.%.bbappend``, then you would have a match. + +In the most general case, you could name the append file something as +simple as ``busybox_%.bbappend`` to be entirely version independent. + +Obtaining BitBake +================= + +You can obtain BitBake several different ways: + +- **Cloning BitBake:** Using Git to clone the BitBake source code + repository is the recommended method for obtaining BitBake. Cloning + the repository makes it easy to get bug fixes and have access to + stable branches and the master branch. Once you have cloned BitBake, + you should use the latest stable branch for development since the + master branch is for BitBake development and might contain less + stable changes. + + You usually need a version of BitBake that matches the metadata you + are using. The metadata is generally backwards compatible but not + forward compatible. + + Here is an example that clones the BitBake repository: :: + + $ git clone git://git.openembedded.org/bitbake + + This command clones the BitBake + Git repository into a directory called ``bitbake``. Alternatively, + you can designate a directory after the ``git clone`` command if you + want to call the new directory something other than ``bitbake``. Here + is an example that names the directory ``bbdev``: :: + + $ git clone git://git.openembedded.org/bitbake bbdev + +- **Installation using your Distribution Package Management System:** + This method is not recommended because the BitBake version that is + provided by your distribution, in most cases, is several releases + behind a snapshot of the BitBake repository. + +- **Taking a snapshot of BitBake:** Downloading a snapshot of BitBake + from the source code repository gives you access to a known branch or + release of BitBake. + + .. note:: + + Cloning the Git repository, as described earlier, is the preferred + method for getting BitBake. Cloning the repository makes it easier + to update as patches are added to the stable branches. + + The following example downloads a snapshot of BitBake version 1.17.0: :: + + $ wget http://git.openembedded.org/bitbake/snapshot/bitbake-1.17.0.tar.gz + $ tar zxpvf bitbake-1.17.0.tar.gz + + After extraction of the tarball using + the tar utility, you have a directory entitled ``bitbake-1.17.0``. + +- **Using the BitBake that Comes With Your Build Checkout:** A final + possibility for getting a copy of BitBake is that it already comes + with your checkout of a larger BitBake-based build system, such as + Poky. Rather than manually checking out individual layers and gluing + them together yourself, you can check out an entire build system. The + checkout will already include a version of BitBake that has been + thoroughly tested for compatibility with the other components. For + information on how to check out a particular BitBake-based build + system, consult that build system's supporting documentation. + +.. _bitbake-user-manual-command: + +The BitBake Command +=================== + +The ``bitbake`` command is the primary interface to the BitBake tool. +This section presents the BitBake command syntax and provides several +execution examples. + +Usage and syntax +---------------- + +Following is the usage and syntax for BitBake: :: + + $ bitbake -h + Usage: bitbake [options] [recipename/target recipe:do_task ...] + + Executes the specified task (default is 'build') for a given set of target recipes (.bb files). + It is assumed there is a conf/bblayers.conf available in cwd or in BBPATH which + will provide the layer, BBFILES and other configuration information. + + Options: + --version show program's version number and exit + -h, --help show this help message and exit + -b BUILDFILE, --buildfile=BUILDFILE + Execute tasks from a specific .bb recipe directly. + WARNING: Does not handle any dependencies from other + recipes. + -k, --continue Continue as much as possible after an error. While the + target that failed and anything depending on it cannot + be built, as much as possible will be built before + stopping. + -f, --force Force the specified targets/task to run (invalidating + any existing stamp file). + -c CMD, --cmd=CMD Specify the task to execute. The exact options + available depend on the metadata. Some examples might + be 'compile' or 'populate_sysroot' or 'listtasks' may + give a list of the tasks available. + -C INVALIDATE_STAMP, --clear-stamp=INVALIDATE_STAMP + Invalidate the stamp for the specified task such as + 'compile' and then run the default task for the + specified target(s). + -r PREFILE, --read=PREFILE + Read the specified file before bitbake.conf. + -R POSTFILE, --postread=POSTFILE + Read the specified file after bitbake.conf. + -v, --verbose Enable tracing of shell tasks (with 'set -x'). Also + print bb.note(...) messages to stdout (in addition to + writing them to ${T}/log.do_<task>). + -D, --debug Increase the debug level. You can specify this more + than once. -D sets the debug level to 1, where only + bb.debug(1, ...) messages are printed to stdout; -DD + sets the debug level to 2, where both bb.debug(1, ...) + and bb.debug(2, ...) messages are printed; etc. + Without -D, no debug messages are printed. Note that + -D only affects output to stdout. All debug messages + are written to ${T}/log.do_taskname, regardless of the + debug level. + -q, --quiet Output less log message data to the terminal. You can + specify this more than once. + -n, --dry-run Don't execute, just go through the motions. + -S SIGNATURE_HANDLER, --dump-signatures=SIGNATURE_HANDLER + Dump out the signature construction information, with + no task execution. The SIGNATURE_HANDLER parameter is + passed to the handler. Two common values are none and + printdiff but the handler may define more/less. none + means only dump the signature, printdiff means compare + the dumped signature with the cached one. + -p, --parse-only Quit after parsing the BB recipes. + -s, --show-versions Show current and preferred versions of all recipes. + -e, --environment Show the global or per-recipe environment complete + with information about where variables were + set/changed. + -g, --graphviz Save dependency tree information for the specified + targets in the dot syntax. + -I EXTRA_ASSUME_PROVIDED, --ignore-deps=EXTRA_ASSUME_PROVIDED + Assume these dependencies don't exist and are already + provided (equivalent to ASSUME_PROVIDED). Useful to + make dependency graphs more appealing + -l DEBUG_DOMAINS, --log-domains=DEBUG_DOMAINS + Show debug logging for the specified logging domains + -P, --profile Profile the command and save reports. + -u UI, --ui=UI The user interface to use (knotty, ncurses or taskexp + - default knotty). + --token=XMLRPCTOKEN Specify the connection token to be used when + connecting to a remote server. + --revisions-changed Set the exit code depending on whether upstream + floating revisions have changed or not. + --server-only Run bitbake without a UI, only starting a server + (cooker) process. + -B BIND, --bind=BIND The name/address for the bitbake xmlrpc server to bind + to. + -T SERVER_TIMEOUT, --idle-timeout=SERVER_TIMEOUT + Set timeout to unload bitbake server due to + inactivity, set to -1 means no unload, default: + Environment variable BB_SERVER_TIMEOUT. + --no-setscene Do not run any setscene tasks. sstate will be ignored + and everything needed, built. + --setscene-only Only run setscene tasks, don't run any real tasks. + --remote-server=REMOTE_SERVER + Connect to the specified server. + -m, --kill-server Terminate any running bitbake server. + --observe-only Connect to a server as an observing-only client. + --status-only Check the status of the remote bitbake server. + -w WRITEEVENTLOG, --write-log=WRITEEVENTLOG + Writes the event log of the build to a bitbake event + json file. Use '' (empty string) to assign the name + automatically. + --runall=RUNALL Run the specified task for any recipe in the taskgraph + of the specified target (even if it wouldn't otherwise + have run). + --runonly=RUNONLY Run only the specified task within the taskgraph of + the specified targets (and any task dependencies those + tasks may have). + +.. _bitbake-examples: + +Examples +-------- + +This section presents some examples showing how to use BitBake. + +.. _example-executing-a-task-against-a-single-recipe: + +Executing a Task Against a Single Recipe +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Executing tasks for a single recipe file is relatively simple. You +specify the file in question, and BitBake parses it and executes the +specified task. If you do not specify a task, BitBake executes the +default task, which is "build”. BitBake obeys inter-task dependencies +when doing so. + +The following command runs the build task, which is the default task, on +the ``foo_1.0.bb`` recipe file: :: + + $ bitbake -b foo_1.0.bb + +The following command runs the clean task on the ``foo.bb`` recipe file: :: + + $ bitbake -b foo.bb -c clean + +.. note:: + + The "-b" option explicitly does not handle recipe dependencies. Other + than for debugging purposes, it is instead recommended that you use + the syntax presented in the next section. + +Executing Tasks Against a Set of Recipe Files +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +There are a number of additional complexities introduced when one wants +to manage multiple ``.bb`` files. Clearly there needs to be a way to +tell BitBake what files are available and, of those, which you want to +execute. There also needs to be a way for each recipe to express its +dependencies, both for build-time and runtime. There must be a way for +you to express recipe preferences when multiple recipes provide the same +functionality, or when there are multiple versions of a recipe. + +The ``bitbake`` command, when not using "--buildfile" or "-b" only +accepts a "PROVIDES". You cannot provide anything else. By default, a +recipe file generally "PROVIDES" its "packagename" as shown in the +following example: :: + + $ bitbake foo + +This next example "PROVIDES" the +package name and also uses the "-c" option to tell BitBake to just +execute the ``do_clean`` task: :: + + $ bitbake -c clean foo + +Executing a List of Task and Recipe Combinations +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +The BitBake command line supports specifying different tasks for +individual targets when you specify multiple targets. For example, +suppose you had two targets (or recipes) ``myfirstrecipe`` and +``mysecondrecipe`` and you needed BitBake to run ``taskA`` for the first +recipe and ``taskB`` for the second recipe: :: + + $ bitbake myfirstrecipe:do_taskA mysecondrecipe:do_taskB + +Generating Dependency Graphs +~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +BitBake is able to generate dependency graphs using the ``dot`` syntax. +You can convert these graphs into images using the ``dot`` tool from +`Graphviz <http://www.graphviz.org>`__. + +When you generate a dependency graph, BitBake writes two files to the +current working directory: + +- ``task-depends.dot``: Shows dependencies between tasks. These + dependencies match BitBake's internal task execution list. + +- ``pn-buildlist``: Shows a simple list of targets that are to be + built. + +To stop depending on common depends, use the "-I" depend option and +BitBake omits them from the graph. Leaving this information out can +produce more readable graphs. This way, you can remove from the graph +``DEPENDS`` from inherited classes such as ``base.bbclass``. + +Here are two examples that create dependency graphs. The second example +omits depends common in OpenEmbedded from the graph: :: + + $ bitbake -g foo + + $ bitbake -g -I virtual/kernel -I eglibc foo + +Executing a Multiple Configuration Build +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +BitBake is able to build multiple images or packages using a single +command where the different targets require different configurations +(multiple configuration builds). Each target, in this scenario, is +referred to as a "multiconfig". + +To accomplish a multiple configuration build, you must define each +target's configuration separately using a parallel configuration file in +the build directory. The location for these multiconfig configuration +files is specific. They must reside in the current build directory in a +sub-directory of ``conf`` named ``multiconfig``. Following is an example +for two separate targets: + +.. image:: figures/bb_multiconfig_files.png + :align: center + +The reason for this required file hierarchy is because the ``BBPATH`` +variable is not constructed until the layers are parsed. Consequently, +using the configuration file as a pre-configuration file is not possible +unless it is located in the current working directory. + +Minimally, each configuration file must define the machine and the +temporary directory BitBake uses for the build. Suggested practice +dictates that you do not overlap the temporary directories used during +the builds. + +Aside from separate configuration files for each target, you must also +enable BitBake to perform multiple configuration builds. Enabling is +accomplished by setting the +:term:`BBMULTICONFIG` variable in the +``local.conf`` configuration file. As an example, suppose you had +configuration files for ``target1`` and ``target2`` defined in the build +directory. The following statement in the ``local.conf`` file both +enables BitBake to perform multiple configuration builds and specifies +the two extra multiconfigs: :: + + BBMULTICONFIG = "target1 target2" + +Once the target configuration files are in place and BitBake has been +enabled to perform multiple configuration builds, use the following +command form to start the builds: :: + + $ bitbake [mc:multiconfigname:]target [[[mc:multiconfigname:]target] ... ] + +Here is an example for two extra multiconfigs: ``target1`` and ``target2``: :: + + $ bitbake mc::target mc:target1:target mc:target2:target + +.. _bb-enabling-multiple-configuration-build-dependencies: + +Enabling Multiple Configuration Build Dependencies +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Sometimes dependencies can exist between targets (multiconfigs) in a +multiple configuration build. For example, suppose that in order to +build an image for a particular architecture, the root filesystem of +another build for a different architecture needs to exist. In other +words, the image for the first multiconfig depends on the root +filesystem of the second multiconfig. This dependency is essentially +that the task in the recipe that builds one multiconfig is dependent on +the completion of the task in the recipe that builds another +multiconfig. + +To enable dependencies in a multiple configuration build, you must +declare the dependencies in the recipe using the following statement +form: :: + + task_or_package[mcdepends] = "mc:from_multiconfig:to_multiconfig:recipe_name:task_on_which_to_depend" + +To better show how to use this statement, consider an example with two +multiconfigs: ``target1`` and ``target2``: :: + + image_task[mcdepends] = "mc:target1:target2:image2:rootfs_task" + +In this example, the +``from_multiconfig`` is "target1" and the ``to_multiconfig`` is "target2". The +task on which the image whose recipe contains image_task depends on the +completion of the rootfs_task used to build out image2, which is +associated with the "target2" multiconfig. + +Once you set up this dependency, you can build the "target1" multiconfig +using a BitBake command as follows: :: + + $ bitbake mc:target1:image1 + +This command executes all the tasks needed to create ``image1`` for the "target1" +multiconfig. Because of the dependency, BitBake also executes through +the ``rootfs_task`` for the "target2" multiconfig build. + +Having a recipe depend on the root filesystem of another build might not +seem that useful. Consider this change to the statement in the image1 +recipe: :: + + image_task[mcdepends] = "mc:target1:target2:image2:image_task" + +In this case, BitBake must create ``image2`` for the "target2" build since +the "target1" build depends on it. + +Because "target1" and "target2" are enabled for multiple configuration +builds and have separate configuration files, BitBake places the +artifacts for each build in the respective temporary build directories. diff --git a/poky/bitbake/doc/bitbake-user-manual/bitbake-user-manual-metadata.rst b/poky/bitbake/doc/bitbake-user-manual/bitbake-user-manual-metadata.rst new file mode 100644 index 000000000..ec5d08590 --- /dev/null +++ b/poky/bitbake/doc/bitbake-user-manual/bitbake-user-manual-metadata.rst @@ -0,0 +1,1969 @@ +.. SPDX-License-Identifier: CC-BY-2.5 + +==================== +Syntax and Operators +==================== + +| + +BitBake files have their own syntax. The syntax has similarities to +several other languages but also has some unique features. This section +describes the available syntax and operators as well as provides +examples. + +Basic Syntax +============ + +This section provides some basic syntax examples. + +Basic Variable Setting +---------------------- + +The following example sets ``VARIABLE`` to "value". This assignment +occurs immediately as the statement is parsed. It is a "hard" +assignment. :: + + VARIABLE = "value" + +As expected, if you include leading or +trailing spaces as part of an assignment, the spaces are retained: :: + + VARIABLE = " value" + VARIABLE = "value " + +Setting ``VARIABLE`` to "" sets +it to an empty string, while setting the variable to " " sets it to a +blank space (i.e. these are not the same values). :: + + VARIABLE = "" + VARIABLE = " " + +You can use single quotes instead of double quotes when setting a +variable's value. Doing so allows you to use values that contain the +double quote character: :: + + VARIABLE = 'I have a " in my value' + +.. note:: + + Unlike in Bourne shells, single quotes work identically to double + quotes in all other ways. They do not suppress variable expansions. + +Modifying Existing Variables +---------------------------- + +Sometimes you need to modify existing variables. Following are some +cases where you might find you want to modify an existing variable: + +- Customize a recipe that uses the variable. + +- Change a variable's default value used in a ``*.bbclass`` file. + +- Change the variable in a ``*.bbappend`` file to override the variable + in the original recipe. + +- Change the variable in a configuration file so that the value + overrides an existing configuration. + +Changing a variable value can sometimes depend on how the value was +originally assigned and also on the desired intent of the change. In +particular, when you append a value to a variable that has a default +value, the resulting value might not be what you expect. In this case, +the value you provide might replace the value rather than append to the +default value. + +If after you have changed a variable's value and something unexplained +occurs, you can use BitBake to check the actual value of the suspect +variable. You can make these checks for both configuration and recipe +level changes: + +- For configuration changes, use the following: :: + + $ bitbake -e + + This + command displays variable values after the configuration files (i.e. + ``local.conf``, ``bblayers.conf``, ``bitbake.conf`` and so forth) + have been parsed. + + .. note:: + + Variables that are exported to the environment are preceded by the + string "export" in the command's output. + +- For recipe changes, use the following: :: + + $ bitbake recipe -e \| grep VARIABLE=" + + This command checks to see if the variable actually makes + it into a specific recipe. + +Line Joining +------------ + +Outside of :ref:`functions <bitbake-user-manual/bitbake-user-manual-metadata:functions>`, +BitBake joins any line ending in +a backslash character ("\") with the following line before parsing +statements. The most common use for the "\" character is to split +variable assignments over multiple lines, as in the following example: :: + + FOO = "bar \ + baz \ + qaz" + +Both the "\" character and the newline +character that follow it are removed when joining lines. Thus, no +newline characters end up in the value of ``FOO``. + +Consider this additional example where the two assignments both assign +"barbaz" to ``FOO``: :: + + FOO = "barbaz" + FOO = "bar\ + baz" + +.. note:: + + BitBake does not interpret escape sequences like "\n" in variable + values. For these to have an effect, the value must be passed to some + utility that interprets escape sequences, such as + ``printf`` or ``echo -n``. + +Variable Expansion +------------------ + +Variables can reference the contents of other variables using a syntax +that is similar to variable expansion in Bourne shells. The following +assignments result in A containing "aval" and B evaluating to +"preavalpost". :: + + A = "aval" + B = "pre${A}post" + +.. note:: + + Unlike in Bourne shells, the curly braces are mandatory: Only ``${FOO}`` and not + ``$FOO`` is recognized as an expansion of ``FOO``. + +The "=" operator does not immediately expand variable references in the +right-hand side. Instead, expansion is deferred until the variable +assigned to is actually used. The result depends on the current values +of the referenced variables. The following example should clarify this +behavior: :: + + A = "${B} baz" + B = "${C} bar" + C = "foo" + *At this point, ${A} equals "foo bar baz"* + C = "qux" + *At this point, ${A} equals "qux bar baz"* + B = "norf" + *At this point, ${A} equals "norf baz"\* + +Contrast this behavior with the +:ref:`bitbake-user-manual/bitbake-user-manual-metadata:immediate variable +expansion (:=)` operator. + +If the variable expansion syntax is used on a variable that does not +exist, the string is kept as is. For example, given the following +assignment, ``BAR`` expands to the literal string "${FOO}" as long as +``FOO`` does not exist. :: + + BAR = "${FOO}" + +Setting a default value (?=) +---------------------------- + +You can use the "?=" operator to achieve a "softer" assignment for a +variable. This type of assignment allows you to define a variable if it +is undefined when the statement is parsed, but to leave the value alone +if the variable has a value. Here is an example: :: + + A ?= "aval" + +If ``A`` is +set at the time this statement is parsed, the variable retains its +value. However, if ``A`` is not set, the variable is set to "aval". + +.. note:: + + This assignment is immediate. Consequently, if multiple "?=" + assignments to a single variable exist, the first of those ends up + getting used. + +Setting a weak default value (??=) +---------------------------------- + +It is possible to use a "weaker" assignment than in the previous section +by using the "??=" operator. This assignment behaves identical to "?=" +except that the assignment is made at the end of the parsing process +rather than immediately. Consequently, when multiple "??=" assignments +exist, the last one is used. Also, any "=" or "?=" assignment will +override the value set with "??=". Here is an example: :: + + A ??= "somevalue" + A ??= "someothervalue" + +If ``A`` is set before the above statements are +parsed, the variable retains its value. If ``A`` is not set, the +variable is set to "someothervalue". + +Again, this assignment is a "lazy" or "weak" assignment because it does +not occur until the end of the parsing process. + +Immediate variable expansion (:=) +--------------------------------- + +The ":=" operator results in a variable's contents being expanded +immediately, rather than when the variable is actually used: :: + + T = "123" + A := "test ${T}" + T = "456" + B := "${T} ${C}" + C = "cval" + C := "${C}append" + +In this example, ``A`` contains "test 123", even though the final value +of ``T`` is "456". The variable ``B`` will end up containing "456 +cvalappend". This is because references to undefined variables are +preserved as is during (immediate)expansion. This is in contrast to GNU +Make, where undefined variables expand to nothing. The variable ``C`` +contains "cvalappend" since ``${C}`` immediately expands to "cval". + +.. _appending-and-prepending: + +Appending (+=) and prepending (=+) With Spaces +---------------------------------------------- + +Appending and prepending values is common and can be accomplished using +the "+=" and "=+" operators. These operators insert a space between the +current value and prepended or appended value. + +These operators take immediate effect during parsing. Here are some +examples: :: + + B = "bval" + B += "additionaldata" + C = "cval" + C =+ "test" + +The variable ``B`` contains "bval additionaldata" and ``C`` contains "test +cval". + +.. _appending-and-prepending-without-spaces: + +Appending (.=) and Prepending (=.) Without Spaces +------------------------------------------------- + +If you want to append or prepend values without an inserted space, use +the ".=" and "=." operators. + +These operators take immediate effect during parsing. Here are some +examples: :: + + B = "bval" + B .= "additionaldata" + C = "cval" + C =. "test" + +The variable ``B`` contains "bvaladditionaldata" and ``C`` contains +"testcval". + +Appending and Prepending (Override Style Syntax) +------------------------------------------------ + +You can also append and prepend a variable's value using an override +style syntax. When you use this syntax, no spaces are inserted. + +These operators differ from the ":=", ".=", "=.", "+=", and "=+" +operators in that their effects are applied at variable expansion time +rather than being immediately applied. Here are some examples: :: + + B = "bval" + B_append = " additional data" + C = "cval" + C_prepend = "additional data " + D = "dval" + D_append = "additional data" + +The variable ``B`` +becomes "bval additional data" and ``C`` becomes "additional data cval". +The variable ``D`` becomes "dvaladditional data". + +.. note:: + + You must control all spacing when you use the override syntax. + +It is also possible to append and prepend to shell functions and +BitBake-style Python functions. See the ":ref:`bitbake-user-manual/bitbake-user-manual-metadata:shell functions`" and ":ref:`bitbake-user-manual/bitbake-user-manual-metadata:bitbake-style python functions`" +sections for examples. + +.. _removing-override-style-syntax: + +Removal (Override Style Syntax) +------------------------------- + +You can remove values from lists using the removal override style +syntax. Specifying a value for removal causes all occurrences of that +value to be removed from the variable. + +When you use this syntax, BitBake expects one or more strings. +Surrounding spaces and spacing are preserved. Here is an example: :: + + FOO = "123 456 789 123456 123 456 123 456" + FOO_remove = "123" + FOO_remove = "456" + FOO2 = " abc def ghi abcdef abc def abc def def" + FOO2_remove = "\ + def \ + abc \ + ghi \ + " + +The variable ``FOO`` becomes +" 789 123456 " and ``FOO2`` becomes " abcdef ". + +Like "_append" and "_prepend", "_remove" is applied at variable +expansion time. + +Override Style Operation Advantages +----------------------------------- + +An advantage of the override style operations "_append", "_prepend", and +"_remove" as compared to the "+=" and "=+" operators is that the +override style operators provide guaranteed operations. For example, +consider a class ``foo.bbclass`` that needs to add the value "val" to +the variable ``FOO``, and a recipe that uses ``foo.bbclass`` as follows: :: + + inherit foo + FOO = "initial" + +If ``foo.bbclass`` uses the "+=" operator, +as follows, then the final value of ``FOO`` will be "initial", which is +not what is desired: :: + + FOO += "val" + +If, on the other hand, ``foo.bbclass`` +uses the "_append" operator, then the final value of ``FOO`` will be +"initial val", as intended: :: + + FOO_append = " val" + +.. note:: + + It is never necessary to use "+=" together with "_append". The following + sequence of assignments appends "barbaz" to FOO: :: + + FOO_append = "bar" + FOO_append = "baz" + + + The only effect of changing the second assignment in the previous + example to use "+=" would be to add a space before "baz" in the + appended value (due to how the "+=" operator works). + +Another advantage of the override style operations is that you can +combine them with other overrides as described in the +":ref:`bitbake-user-manual/bitbake-user-manual-metadata:conditional syntax (overrides)`" section. + +Variable Flag Syntax +-------------------- + +Variable flags are BitBake's implementation of variable properties or +attributes. It is a way of tagging extra information onto a variable. +You can find more out about variable flags in general in the +":ref:`bitbake-user-manual/bitbake-user-manual-metadata:variable flags`" section. + +You can define, append, and prepend values to variable flags. All the +standard syntax operations previously mentioned work for variable flags +except for override style syntax (i.e. "_prepend", "_append", and +"_remove"). + +Here are some examples showing how to set variable flags: :: + + FOO[a] = "abc" + FOO[b] = "123" + FOO[a] += "456" + +The variable ``FOO`` has two flags: +``[a]`` and ``[b]``. The flags are immediately set to "abc" and "123", +respectively. The ``[a]`` flag becomes "abc 456". + +No need exists to pre-define variable flags. You can simply start using +them. One extremely common application is to attach some brief +documentation to a BitBake variable as follows: :: + + CACHE[doc] = "The directory holding the cache of the metadata." + +Inline Python Variable Expansion +-------------------------------- + +You can use inline Python variable expansion to set variables. Here is +an example: :: + + DATE = "${@time.strftime('%Y%m%d',time.gmtime())}" + +This example results in the ``DATE`` variable being set to the current date. + +Probably the most common use of this feature is to extract the value of +variables from BitBake's internal data dictionary, ``d``. The following +lines select the values of a package name and its version number, +respectively: :: + + PN = "${@bb.parse.BBHandler.vars_from_file(d.getVar('FILE', False),d)[0] or 'defaultpkgname'}" + PV = "${@bb.parse.BBHandler.vars_from_file(d.getVar('FILE', False),d)[1] or '1.0'}" + +.. note:: + + Inline Python expressions work just like variable expansions insofar as the + "=" and ":=" operators are concerned. Given the following assignment, foo() + is called each time FOO is expanded: :: + + FOO = "${@foo()}" + + Contrast this with the following immediate assignment, where foo() is only + called once, while the assignment is parsed: :: + + FOO := "${@foo()}" + +For a different way to set variables with Python code during parsing, +see the +":ref:`bitbake-user-manual/bitbake-user-manual-metadata:anonymous python functions`" section. + +Unsetting variables +------------------- + +It is possible to completely remove a variable or a variable flag from +BitBake's internal data dictionary by using the "unset" keyword. Here is +an example: :: + + unset DATE + unset do_fetch[noexec] + +These two statements remove the ``DATE`` and the ``do_fetch[noexec]`` flag. + +Providing Pathnames +------------------- + +When specifying pathnames for use with BitBake, do not use the tilde +("~") character as a shortcut for your home directory. Doing so might +cause BitBake to not recognize the path since BitBake does not expand +this character in the same way a shell would. + +Instead, provide a fuller path as the following example illustrates: :: + + BBLAYERS ?= " \ + /home/scott-lenovo/LayerA \ + " + +Exporting Variables to the Environment +====================================== + +You can export variables to the environment of running tasks by using +the ``export`` keyword. For example, in the following example, the +``do_foo`` task prints "value from the environment" when run: :: + + export ENV_VARIABLE + ENV_VARIABLE = "value from the environment" + + do_foo() { + bbplain "$ENV_VARIABLE" + } + +.. note:: + + BitBake does not expand ``$ENV_VARIABLE`` in this case because it lacks the + obligatory ``{}`` . Rather, ``$ENV_VARIABLE`` is expanded by the shell. + +It does not matter whether ``export ENV_VARIABLE`` appears before or +after assignments to ``ENV_VARIABLE``. + +It is also possible to combine ``export`` with setting a value for the +variable. Here is an example: :: + + export ENV_VARIABLE = "variable-value" + +In the output of ``bitbake -e``, variables that are exported to the +environment are preceded by "export". + +Among the variables commonly exported to the environment are ``CC`` and +``CFLAGS``, which are picked up by many build systems. + +Conditional Syntax (Overrides) +============================== + +BitBake uses :term:`OVERRIDES` to control what +variables are overridden after BitBake parses recipes and configuration +files. This section describes how you can use ``OVERRIDES`` as +conditional metadata, talks about key expansion in relationship to +``OVERRIDES``, and provides some examples to help with understanding. + +Conditional Metadata +-------------------- + +You can use ``OVERRIDES`` to conditionally select a specific version of +a variable and to conditionally append or prepend the value of a +variable. + +.. note:: + + Overrides can only use lower-case characters. Additionally, + underscores are not permitted in override names as they are used to + separate overrides from each other and from the variable name. + +- *Selecting a Variable:* The ``OVERRIDES`` variable is a + colon-character-separated list that contains items for which you want + to satisfy conditions. Thus, if you have a variable that is + conditional on “arm”, and “arm” is in ``OVERRIDES``, then the + “arm”-specific version of the variable is used rather than the + non-conditional version. Here is an example: :: + + OVERRIDES = "architecture:os:machine" + TEST = "default" + TEST_os = "osspecific" + TEST_nooverride = "othercondvalue" + + In this example, the ``OVERRIDES`` + variable lists three overrides: "architecture", "os", and "machine". + The variable ``TEST`` by itself has a default value of "default". You + select the os-specific version of the ``TEST`` variable by appending + the "os" override to the variable (i.e. ``TEST_os``). + + To better understand this, consider a practical example that assumes + an OpenEmbedded metadata-based Linux kernel recipe file. The + following lines from the recipe file first set the kernel branch + variable ``KBRANCH`` to a default value, then conditionally override + that value based on the architecture of the build: :: + + KBRANCH = "standard/base" + KBRANCH_qemuarm = "standard/arm-versatile-926ejs" + KBRANCH_qemumips = "standard/mti-malta32" + KBRANCH_qemuppc = "standard/qemuppc" + KBRANCH_qemux86 = "standard/common-pc/base" + KBRANCH_qemux86-64 = "standard/common-pc-64/base" + KBRANCH_qemumips64 = "standard/mti-malta64" + +- *Appending and Prepending:* BitBake also supports append and prepend + operations to variable values based on whether a specific item is + listed in ``OVERRIDES``. Here is an example: :: + + DEPENDS = "glibc ncurses" + OVERRIDES = "machine:local" + DEPENDS_append_machine = "libmad" + + In this example, ``DEPENDS`` becomes "glibc ncurses libmad". + + Again, using an OpenEmbedded metadata-based kernel recipe file as an + example, the following lines will conditionally append to the + ``KERNEL_FEATURES`` variable based on the architecture: :: + + KERNEL_FEATURES_append = " ${KERNEL_EXTRA_FEATURES}" + KERNEL_FEATURES_append_qemux86=" cfg/sound.scc cfg/paravirt_kvm.scc" + KERNEL_FEATURES_append_qemux86-64=" cfg/sound.scc cfg/paravirt_kvm.scc" + +- *Setting a Variable for a Single Task:* BitBake supports setting a + variable just for the duration of a single task. Here is an example: :: + + FOO_task-configure = "val 1" + FOO_task-compile = "val 2" + + In the + previous example, ``FOO`` has the value "val 1" while the + ``do_configure`` task is executed, and the value "val 2" while the + ``do_compile`` task is executed. + + Internally, this is implemented by prepending the task (e.g. + "task-compile:") to the value of + :term:`OVERRIDES` for the local datastore of the + ``do_compile`` task. + + You can also use this syntax with other combinations (e.g. + "``_prepend``") as shown in the following example: :: + + EXTRA_OEMAKE_prepend_task-compile = "${PARALLEL_MAKE} " + +Key Expansion +------------- + +Key expansion happens when the BitBake datastore is finalized. To better +understand this, consider the following example: :: + + A${B} = "X" + B = "2" + A2 = "Y" + +In this case, after all the parsing is complete, BitBake expands +``${B}`` into "2". This expansion causes ``A2``, which was set to "Y" +before the expansion, to become "X". + +.. _variable-interaction-worked-examples: + +Examples +-------- + +Despite the previous explanations that show the different forms of +variable definitions, it can be hard to work out exactly what happens +when variable operators, conditional overrides, and unconditional +overrides are combined. This section presents some common scenarios +along with explanations for variable interactions that typically confuse +users. + +There is often confusion concerning the order in which overrides and +various "append" operators take effect. Recall that an append or prepend +operation using "_append" and "_prepend" does not result in an immediate +assignment as would "+=", ".=", "=+", or "=.". Consider the following +example: :: + + OVERRIDES = "foo" + A = "Z" + A_foo_append = "X" + +For this case, +``A`` is unconditionally set to "Z" and "X" is unconditionally and +immediately appended to the variable ``A_foo``. Because overrides have +not been applied yet, ``A_foo`` is set to "X" due to the append and +``A`` simply equals "Z". + +Applying overrides, however, changes things. Since "foo" is listed in +``OVERRIDES``, the conditional variable ``A`` is replaced with the "foo" +version, which is equal to "X". So effectively, ``A_foo`` replaces +``A``. + +This next example changes the order of the override and the append: :: + + OVERRIDES = "foo" + A = "Z" + A_append_foo = "X" + +For this case, before +overrides are handled, ``A`` is set to "Z" and ``A_append_foo`` is set +to "X". Once the override for "foo" is applied, however, ``A`` gets +appended with "X". Consequently, ``A`` becomes "ZX". Notice that spaces +are not appended. + +This next example has the order of the appends and overrides reversed +back as in the first example: :: + + OVERRIDES = "foo" + A = "Y" + A_foo_append = "Z" + A_foo_append = "X" + +For this case, before any overrides are resolved, +``A`` is set to "Y" using an immediate assignment. After this immediate +assignment, ``A_foo`` is set to "Z", and then further appended with "X" +leaving the variable set to "ZX". Finally, applying the override for +"foo" results in the conditional variable ``A`` becoming "ZX" (i.e. +``A`` is replaced with ``A_foo``). + +This final example mixes in some varying operators: :: + + A = "1" + A_append = "2" + A_append = "3" + A += "4" + A .= "5" + +For this case, the type of append +operators are affecting the order of assignments as BitBake passes +through the code multiple times. Initially, ``A`` is set to "1 45" +because of the three statements that use immediate operators. After +these assignments are made, BitBake applies the "_append" operations. +Those operations result in ``A`` becoming "1 4523". + +Sharing Functionality +===================== + +BitBake allows for metadata sharing through include files (``.inc``) and +class files (``.bbclass``). For example, suppose you have a piece of +common functionality such as a task definition that you want to share +between more than one recipe. In this case, creating a ``.bbclass`` file +that contains the common functionality and then using the ``inherit`` +directive in your recipes to inherit the class would be a common way to +share the task. + +This section presents the mechanisms BitBake provides to allow you to +share functionality between recipes. Specifically, the mechanisms +include ``include``, ``inherit``, ``INHERIT``, and ``require`` +directives. + +Locating Include and Class Files +-------------------------------- + +BitBake uses the :term:`BBPATH` variable to locate +needed include and class files. Additionally, BitBake searches the +current directory for ``include`` and ``require`` directives. + +.. note:: + + The BBPATH variable is analogous to the environment variable PATH . + +In order for include and class files to be found by BitBake, they need +to be located in a "classes" subdirectory that can be found in +``BBPATH``. + +``inherit`` Directive +--------------------- + +When writing a recipe or class file, you can use the ``inherit`` +directive to inherit the functionality of a class (``.bbclass``). +BitBake only supports this directive when used within recipe and class +files (i.e. ``.bb`` and ``.bbclass``). + +The ``inherit`` directive is a rudimentary means of specifying +functionality contained in class files that your recipes require. For +example, you can easily abstract out the tasks involved in building a +package that uses Autoconf and Automake and put those tasks into a class +file and then have your recipe inherit that class file. + +As an example, your recipes could use the following directive to inherit +an ``autotools.bbclass`` file. The class file would contain common +functionality for using Autotools that could be shared across recipes: :: + + inherit autotools + +In this case, BitBake would search for the directory +``classes/autotools.bbclass`` in ``BBPATH``. + +.. note:: + + You can override any values and functions of the inherited class + within your recipe by doing so after the "inherit" statement. + +If you want to use the directive to inherit multiple classes, separate +them with spaces. The following example shows how to inherit both the +``buildhistory`` and ``rm_work`` classes: :: + + inherit buildhistory rm_work + +An advantage with the inherit directive as compared to both the +:ref:`include <bitbake-user-manual/bitbake-user-manual-metadata:\`\`include\`\` directive>` and :ref:`require <bitbake-user-manual/bitbake-user-manual-metadata:\`\`require\`\` directive>` +directives is that you can inherit class files conditionally. You can +accomplish this by using a variable expression after the ``inherit`` +statement. Here is an example: :: + + inherit ${VARNAME} + +If ``VARNAME`` is +going to be set, it needs to be set before the ``inherit`` statement is +parsed. One way to achieve a conditional inherit in this case is to use +overrides: :: + + VARIABLE = "" + VARIABLE_someoverride = "myclass" + +Another method is by using anonymous Python. Here is an example: :: + + python () { + if condition == value: + d.setVar('VARIABLE', 'myclass') + else: + d.setVar('VARIABLE', '') + } + +Alternatively, you could use an in-line Python expression in the +following form: :: + + inherit ${@'classname' if condition else ''} + inherit ${@functionname(params)} + +In all cases, if the expression evaluates to an +empty string, the statement does not trigger a syntax error because it +becomes a no-op. + +``include`` Directive +--------------------- + +BitBake understands the ``include`` directive. This directive causes +BitBake to parse whatever file you specify, and to insert that file at +that location. The directive is much like its equivalent in Make except +that if the path specified on the include line is a relative path, +BitBake locates the first file it can find within ``BBPATH``. + +The include directive is a more generic method of including +functionality as compared to the :ref:`inherit <bitbake-user-manual/bitbake-user-manual-metadata:\`\`inherit\`\` directive>` +directive, which is restricted to class (i.e. ``.bbclass``) files. The +include directive is applicable for any other kind of shared or +encapsulated functionality or configuration that does not suit a +``.bbclass`` file. + +As an example, suppose you needed a recipe to include some self-test +definitions: :: + + include test_defs.inc + +.. note:: + + The include directive does not produce an error when the file cannot be + found. Consequently, it is recommended that if the file you are including is + expected to exist, you should use :ref:`require <require-inclusion>` instead + of include . Doing so makes sure that an error is produced if the file cannot + be found. + +.. _require-inclusion: + +``require`` Directive +--------------------- + +BitBake understands the ``require`` directive. This directive behaves +just like the ``include`` directive with the exception that BitBake +raises a parsing error if the file to be included cannot be found. Thus, +any file you require is inserted into the file that is being parsed at +the location of the directive. + +The require directive, like the include directive previously described, +is a more generic method of including functionality as compared to the +:ref:`inherit <bitbake-user-manual/bitbake-user-manual-metadata:\`\`inherit\`\` directive>` directive, which is restricted to class +(i.e. ``.bbclass``) files. The require directive is applicable for any +other kind of shared or encapsulated functionality or configuration that +does not suit a ``.bbclass`` file. + +Similar to how BitBake handles :ref:`include <bitbake-user-manual/bitbake-user-manual-metadata:\`\`include\`\` directive>`, if +the path specified on the require line is a relative path, BitBake +locates the first file it can find within ``BBPATH``. + +As an example, suppose you have two versions of a recipe (e.g. +``foo_1.2.2.bb`` and ``foo_2.0.0.bb``) where each version contains some +identical functionality that could be shared. You could create an +include file named ``foo.inc`` that contains the common definitions +needed to build "foo". You need to be sure ``foo.inc`` is located in the +same directory as your two recipe files as well. Once these conditions +are set up, you can share the functionality using a ``require`` +directive from within each recipe: :: + + require foo.inc + +``INHERIT`` Configuration Directive +----------------------------------- + +When creating a configuration file (``.conf``), you can use the +:term:`INHERIT` configuration directive to inherit a +class. BitBake only supports this directive when used within a +configuration file. + +As an example, suppose you needed to inherit a class file called +``abc.bbclass`` from a configuration file as follows: :: + + INHERIT += "abc" + +This configuration directive causes the named class to be inherited at +the point of the directive during parsing. As with the ``inherit`` +directive, the ``.bbclass`` file must be located in a "classes" +subdirectory in one of the directories specified in ``BBPATH``. + +.. note:: + + Because .conf files are parsed first during BitBake's execution, using + INHERIT to inherit a class effectively inherits the class globally (i.e. for + all recipes). + +If you want to use the directive to inherit multiple classes, you can +provide them on the same line in the ``local.conf`` file. Use spaces to +separate the classes. The following example shows how to inherit both +the ``autotools`` and ``pkgconfig`` classes: :: + + INHERIT += "autotools pkgconfig" + +Functions +========= + +As with most languages, functions are the building blocks that are used +to build up operations into tasks. BitBake supports these types of +functions: + +- *Shell Functions:* Functions written in shell script and executed + either directly as functions, tasks, or both. They can also be called + by other shell functions. + +- *BitBake-Style Python Functions:* Functions written in Python and + executed by BitBake or other Python functions using + ``bb.build.exec_func()``. + +- *Python Functions:* Functions written in Python and executed by + Python. + +- *Anonymous Python Functions:* Python functions executed automatically + during parsing. + +Regardless of the type of function, you can only define them in class +(``.bbclass``) and recipe (``.bb`` or ``.inc``) files. + +Shell Functions +--------------- + +Functions written in shell script and executed either directly as +functions, tasks, or both. They can also be called by other shell +functions. Here is an example shell function definition: :: + + some_function () { + echo "Hello World" + } + +When you create these types of functions in +your recipe or class files, you need to follow the shell programming +rules. The scripts are executed by ``/bin/sh``, which may not be a bash +shell but might be something such as ``dash``. You should not use +Bash-specific script (bashisms). + +Overrides and override-style operators like ``_append`` and ``_prepend`` +can also be applied to shell functions. Most commonly, this application +would be used in a ``.bbappend`` file to modify functions in the main +recipe. It can also be used to modify functions inherited from classes. + +As an example, consider the following: :: + + do_foo() { + bbplain first + fn + } + + fn_prepend() { + bbplain second + } + + fn() { + bbplain third + } + + do_foo_append() { + bbplain fourth + } + +Running ``do_foo`` prints the following: :: + + recipename do_foo: first + recipename do_foo: second + recipename do_foo: third + recipename do_foo: fourth + +.. note:: + + Overrides and override-style operators can be applied to any shell + function, not just :ref:`tasks <bitbake-user-manual/bitbake-user-manual-metadata:tasks>`. + +You can use the ``bitbake -e`` recipename command to view the final +assembled function after all overrides have been applied. + +BitBake-Style Python Functions +------------------------------ + +These functions are written in Python and executed by BitBake or other +Python functions using ``bb.build.exec_func()``. + +An example BitBake function is: :: + + python some_python_function () { + d.setVar("TEXT", "Hello World") + print d.getVar("TEXT") + } + +Because the +Python "bb" and "os" modules are already imported, you do not need to +import these modules. Also in these types of functions, the datastore +("d") is a global variable and is always automatically available. + +.. note:: + + Variable expressions (e.g. ``${X}`` ) are no longer expanded within Python + functions. This behavior is intentional in order to allow you to freely set + variable values to expandable expressions without having them expanded + prematurely. If you do wish to expand a variable within a Python function, + use ``d.getVar("X")`` . Or, for more complicated expressions, use ``d.expand()``. + +Similar to shell functions, you can also apply overrides and +override-style operators to BitBake-style Python functions. + +As an example, consider the following: :: + + python do_foo_prepend() { + bb.plain("first") + } + + python do_foo() { + bb.plain("second") + } + + python do_foo_append() { + bb.plain("third") + } + +Running ``do_foo`` prints the following: :: + + recipename do_foo: first + recipename do_foo: second + recipename do_foo: third + +You can use the ``bitbake -e`` recipename command to view +the final assembled function after all overrides have been applied. + +Python Functions +---------------- + +These functions are written in Python and are executed by other Python +code. Examples of Python functions are utility functions that you intend +to call from in-line Python or from within other Python functions. Here +is an example: :: + + def get_depends(d): + if d.getVar('SOMECONDITION'): + return "dependencywithcond" + else: + return "dependency" + + SOMECONDITION = "1" + DEPENDS = "${@get_depends(d)}" + +This would result in ``DEPENDS`` containing ``dependencywithcond``. + +Here are some things to know about Python functions: + +- Python functions can take parameters. + +- The BitBake datastore is not automatically available. Consequently, + you must pass it in as a parameter to the function. + +- The "bb" and "os" Python modules are automatically available. You do + not need to import them. + +BitBake-Style Python Functions Versus Python Functions +------------------------------------------------------ + +Following are some important differences between BitBake-style Python +functions and regular Python functions defined with "def": + +- Only BitBake-style Python functions can be :ref:`tasks <bitbake-user-manual/bitbake-user-manual-metadata:tasks>`. + +- Overrides and override-style operators can only be applied to + BitBake-style Python functions. + +- Only regular Python functions can take arguments and return values. + +- :ref:`Variable flags <bitbake-user-manual/bitbake-user-manual-metadata:variable flags>` such as + ``[dirs]``, ``[cleandirs]``, and ``[lockfiles]`` can be used on BitBake-style + Python functions, but not on regular Python functions. + +- BitBake-style Python functions generate a separate + ``${``\ :term:`T`\ ``}/run.``\ function-name\ ``.``\ pid + script that is executed to run the function, and also generate a log + file in ``${T}/log.``\ function-name\ ``.``\ pid if they are executed + as tasks. + + Regular Python functions execute "inline" and do not generate any + files in ``${T}``. + +- Regular Python functions are called with the usual Python syntax. + BitBake-style Python functions are usually tasks and are called + directly by BitBake, but can also be called manually from Python code + by using the ``bb.build.exec_func()`` function. Here is an example: :: + + bb.build.exec_func("my_bitbake_style_function", d) + + .. note:: + + ``bb.build.exec_func()`` can also be used to run shell functions from Python + code. If you want to run a shell function before a Python function within + the same task, then you can use a parent helper Python function that + starts by running the shell function with ``bb.build.exec_func()`` and then + runs the Python code. + + To detect errors from functions executed with + ``bb.build.exec_func()``, you can catch the ``bb.build.FuncFailed`` + exception. + + .. note:: + + Functions in metadata (recipes and classes) should not themselves raise + ``bb.build.FuncFailed``. Rather, ``bb.build.FuncFailed`` should be viewed as a + general indicator that the called function failed by raising an + exception. For example, an exception raised by ``bb.fatal()`` will be caught + inside ``bb.build.exec_func()``, and a ``bb.build.FuncFailed`` will be raised in + response. + +Due to their simplicity, you should prefer regular Python functions over +BitBake-style Python functions unless you need a feature specific to +BitBake-style Python functions. Regular Python functions in metadata are +a more recent invention than BitBake-style Python functions, and older +code tends to use ``bb.build.exec_func()`` more often. + +Anonymous Python Functions +-------------------------- + +Sometimes it is useful to set variables or perform other operations +programmatically during parsing. To do this, you can define special +Python functions, called anonymous Python functions, that run at the end +of parsing. For example, the following conditionally sets a variable +based on the value of another variable: :: + + python () { + if d.getVar('SOMEVAR') == 'value': + d.setVar('ANOTHERVAR', 'value2') + } + +An equivalent way to mark a function as an anonymous function is to give it +the name "__anonymous", rather than no name. + +Anonymous Python functions always run at the end of parsing, regardless +of where they are defined. If a recipe contains many anonymous +functions, they run in the same order as they are defined within the +recipe. As an example, consider the following snippet: :: + + python () { + d.setVar('FOO', 'foo 2') + } + + FOO = "foo 1" + + python () { + d.appendVar('BAR',' bar 2') + } + + BAR = "bar 1" + +The previous example is conceptually +equivalent to the following snippet: :: + + FOO = "foo 1" + BAR = "bar 1" + FOO = "foo 2" + BAR += "bar 2" + +``FOO`` ends up with the value "foo 2", and +``BAR`` with the value "bar 1 bar 2". Just as in the second snippet, the +values set for the variables within the anonymous functions become +available to tasks, which always run after parsing. + +Overrides and override-style operators such as "``_append``" are applied +before anonymous functions run. In the following example, ``FOO`` ends +up with the value "foo from anonymous": :: + + FOO = "foo" + FOO_append = " from outside" + + python () { + d.setVar("FOO", "foo from anonymous") + } + +For methods +you can use with anonymous Python functions, see the +":ref:`bitbake-user-manual/bitbake-user-manual-metadata:functions you can call from within python`" +section. For a different method to run Python code during parsing, see +the ":ref:`bitbake-user-manual/bitbake-user-manual-metadata:inline python variable expansion`" section. + +Flexible Inheritance for Class Functions +---------------------------------------- + +Through coding techniques and the use of ``EXPORT_FUNCTIONS``, BitBake +supports exporting a function from a class such that the class function +appears as the default implementation of the function, but can still be +called if a recipe inheriting the class needs to define its own version +of the function. + +To understand the benefits of this feature, consider the basic scenario +where a class defines a task function and your recipe inherits the +class. In this basic scenario, your recipe inherits the task function as +defined in the class. If desired, your recipe can add to the start and +end of the function by using the "_prepend" or "_append" operations +respectively, or it can redefine the function completely. However, if it +redefines the function, there is no means for it to call the class +version of the function. ``EXPORT_FUNCTIONS`` provides a mechanism that +enables the recipe's version of the function to call the original +version of the function. + +To make use of this technique, you need the following things in place: + +- The class needs to define the function as follows: :: + + classname_functionname + + For example, if you have a class file + ``bar.bbclass`` and a function named ``do_foo``, the class must + define the function as follows: :: + + bar_do_foo + +- The class needs to contain the ``EXPORT_FUNCTIONS`` statement as + follows: :: + + EXPORT_FUNCTIONS functionname + + For example, continuing with + the same example, the statement in the ``bar.bbclass`` would be as + follows: :: + + EXPORT_FUNCTIONS do_foo + +- You need to call the function appropriately from within your recipe. + Continuing with the same example, if your recipe needs to call the + class version of the function, it should call ``bar_do_foo``. + Assuming ``do_foo`` was a shell function and ``EXPORT_FUNCTIONS`` was + used as above, the recipe's function could conditionally call the + class version of the function as follows: :: + + do_foo() { + if [ somecondition ] ; then + bar_do_foo + else + # Do something else + fi + } + + To call your modified version of the function as defined in your recipe, + call it as ``do_foo``. + +With these conditions met, your single recipe can freely choose between +the original function as defined in the class file and the modified +function in your recipe. If you do not set up these conditions, you are +limited to using one function or the other. + +Tasks +===== + +Tasks are BitBake execution units that make up the steps that BitBake +can run for a given recipe. Tasks are only supported in recipes and +classes (i.e. in ``.bb`` files and files included or inherited from +``.bb`` files). By convention, tasks have names that start with "do\_". + +Promoting a Function to a Task +------------------------------ + +Tasks are either :ref:`shell functions <bitbake-user-manual/bitbake-user-manual-metadata:shell functions>` or +:ref:`BitBake-style Python functions <bitbake-user-manual/bitbake-user-manual-metadata:bitbake-style python functions>` +that have been promoted to tasks by using the ``addtask`` command. The +``addtask`` command can also optionally describe dependencies between +the task and other tasks. Here is an example that shows how to define a +task and declare some dependencies: :: + + python do_printdate () { + import time + print time.strftime('%Y%m%d', time.gmtime()) + } + addtask printdate after do_fetch before do_build + +The first argument to ``addtask`` is the name +of the function to promote to a task. If the name does not start with +"do\_", "do\_" is implicitly added, which enforces the convention that all +task names start with "do\_". + +In the previous example, the ``do_printdate`` task becomes a dependency +of the ``do_build`` task, which is the default task (i.e. the task run +by the ``bitbake`` command unless another task is specified explicitly). +Additionally, the ``do_printdate`` task becomes dependent upon the +``do_fetch`` task. Running the ``do_build`` task results in the +``do_printdate`` task running first. + +.. note:: + + If you try out the previous example, you might see that the + ``do_printdate`` + task is only run the first time you build the recipe with the + ``bitbake`` + command. This is because BitBake considers the task "up-to-date" + after that initial run. If you want to force the task to always be + rerun for experimentation purposes, you can make BitBake always + consider the task "out-of-date" by using the + :ref:`[nostamp] <bitbake-user-manual/bitbake-user-manual-metadata:Variable Flags>` + variable flag, as follows: :: + + do_printdate[nostamp] = "1" + + You can also explicitly run the task and provide the + -f option as follows: :: + + $ bitbake recipe -c printdate -f + + When manually selecting a task to run with the bitbake ``recipe + -c task`` command, you can omit the "do\_" prefix as part of the task + name. + +You might wonder about the practical effects of using ``addtask`` +without specifying any dependencies as is done in the following example: :: + + addtask printdate + +In this example, assuming dependencies have not been +added through some other means, the only way to run the task is by +explicitly selecting it with ``bitbake`` recipe ``-c printdate``. You +can use the ``do_listtasks`` task to list all tasks defined in a recipe +as shown in the following example: :: + + $ bitbake recipe -c listtasks + +For more information on task dependencies, see the +":ref:`bitbake-user-manual/bitbake-user-manual-execution:dependencies`" section. + +See the ":ref:`bitbake-user-manual/bitbake-user-manual-metadata:variable flags`" section for information +on variable flags you can use with tasks. + +Deleting a Task +--------------- + +As well as being able to add tasks, you can delete them. Simply use the +``deltask`` command to delete a task. For example, to delete the example +task used in the previous sections, you would use: :: + + deltask printdate + +If you delete a task using the ``deltask`` command and the task has +dependencies, the dependencies are not reconnected. For example, suppose +you have three tasks named ``do_a``, ``do_b``, and ``do_c``. +Furthermore, ``do_c`` is dependent on ``do_b``, which in turn is +dependent on ``do_a``. Given this scenario, if you use ``deltask`` to +delete ``do_b``, the implicit dependency relationship between ``do_c`` +and ``do_a`` through ``do_b`` no longer exists, and ``do_c`` +dependencies are not updated to include ``do_a``. Thus, ``do_c`` is free +to run before ``do_a``. + +If you want dependencies such as these to remain intact, use the +``[noexec]`` varflag to disable the task instead of using the +``deltask`` command to delete it: :: + + do_b[noexec] = "1" + +Passing Information Into the Build Task Environment +--------------------------------------------------- + +When running a task, BitBake tightly controls the shell execution +environment of the build tasks to make sure unwanted contamination from +the build machine cannot influence the build. + +.. note:: + + By default, BitBake cleans the environment to include only those + things exported or listed in its whitelist to ensure that the build + environment is reproducible and consistent. You can prevent this + "cleaning" by setting the :term:`BB_PRESERVE_ENV` variable. + +Consequently, if you do want something to get passed into the build task +environment, you must take these two steps: + +#. Tell BitBake to load what you want from the environment into the + datastore. You can do so through the + :term:`BB_ENV_WHITELIST` and + :term:`BB_ENV_EXTRAWHITE` variables. For + example, assume you want to prevent the build system from accessing + your ``$HOME/.ccache`` directory. The following command "whitelists" + the environment variable ``CCACHE_DIR`` causing BitBake to allow that + variable into the datastore: :: + + export BB_ENV_EXTRAWHITE="$BB_ENV_EXTRAWHITE CCACHE_DIR" + +#. Tell BitBake to export what you have loaded into the datastore to the + task environment of every running task. Loading something from the + environment into the datastore (previous step) only makes it + available in the datastore. To export it to the task environment of + every running task, use a command similar to the following in your + local configuration file ``local.conf`` or your distribution + configuration file: :: + + export CCACHE_DIR + + .. note:: + + A side effect of the previous steps is that BitBake records the + variable as a dependency of the build process in things like the + setscene checksums. If doing so results in unnecessary rebuilds of + tasks, you can whitelist the variable so that the setscene code + ignores the dependency when it creates checksums. + +Sometimes, it is useful to be able to obtain information from the +original execution environment. BitBake saves a copy of the original +environment into a special variable named :term:`BB_ORIGENV`. + +The ``BB_ORIGENV`` variable returns a datastore object that can be +queried using the standard datastore operators such as +``getVar(, False)``. The datastore object is useful, for example, to +find the original ``DISPLAY`` variable. Here is an example: :: + + origenv = d.getVar("BB_ORIGENV", False) + bar = origenv.getVar("BAR", False) + +The previous example returns ``BAR`` from the original execution +environment. + +Variable Flags +============== + +Variable flags (varflags) help control a task's functionality and +dependencies. BitBake reads and writes varflags to the datastore using +the following command forms: :: + + variable = d.getVarFlags("variable") + self.d.setVarFlags("FOO", {"func": True}) + +When working with varflags, the same syntax, with the exception of +overrides, applies. In other words, you can set, append, and prepend +varflags just like variables. See the +":ref:`bitbake-user-manual/bitbake-user-manual-metadata:variable flag syntax`" section for details. + +BitBake has a defined set of varflags available for recipes and classes. +Tasks support a number of these flags which control various +functionality of the task: + +- ``[cleandirs]``: Empty directories that should be created before + the task runs. Directories that already exist are removed and + recreated to empty them. + +- ``[depends]``: Controls inter-task dependencies. See the + :term:`DEPENDS` variable and the + ":ref:`bitbake-user-manual/bitbake-user-manual-metadata:inter-task + dependencies`" section for more information. + +- ``[deptask]``: Controls task build-time dependencies. See the + :term:`DEPENDS` variable and the ":ref:`bitbake-user-manual/bitbake-user-manual-metadata:build dependencies`" section for more information. + +- ``[dirs]``: Directories that should be created before the task + runs. Directories that already exist are left as is. The last + directory listed is used as the current working directory for the + task. + +- ``[lockfiles]``: Specifies one or more lockfiles to lock while the + task executes. Only one task may hold a lockfile, and any task that + attempts to lock an already locked file will block until the lock is + released. You can use this variable flag to accomplish mutual + exclusion. + +- ``[noexec]``: When set to "1", marks the task as being empty, with + no execution required. You can use the ``[noexec]`` flag to set up + tasks as dependency placeholders, or to disable tasks defined + elsewhere that are not needed in a particular recipe. + +- ``[nostamp]``: When set to "1", tells BitBake to not generate a + stamp file for a task, which implies the task should always be + executed. + + .. caution:: + + Any task that depends (possibly indirectly) on a ``[nostamp]`` task will + always be executed as well. This can cause unnecessary rebuilding if you + are not careful. + +- ``[number_threads]``: Limits tasks to a specific number of + simultaneous threads during execution. This varflag is useful when + your build host has a large number of cores but certain tasks need to + be rate-limited due to various kinds of resource constraints (e.g. to + avoid network throttling). ``number_threads`` works similarly to the + :term:`BB_NUMBER_THREADS` variable but is task-specific. + + Set the value globally. For example, the following makes sure the + ``do_fetch`` task uses no more than two simultaneous execution + threads: do_fetch[number_threads] = "2" + + .. warning:: + + - Setting the varflag in individual recipes rather than globally + can result in unpredictable behavior. + + - Setting the varflag to a value greater than the value used in + the ``BB_NUMBER_THREADS`` variable causes ``number_threads`` to + have no effect. + +- ``[postfuncs]``: List of functions to call after the completion of + the task. + +- ``[prefuncs]``: List of functions to call before the task executes. + +- ``[rdepends]``: Controls inter-task runtime dependencies. See the + :term:`RDEPENDS` variable, the + :term:`RRECOMMENDS` variable, and the + ":ref:`bitbake-user-manual/bitbake-user-manual-metadata:inter-task dependencies`" section for + more information. + +- ``[rdeptask]``: Controls task runtime dependencies. See the + :term:`RDEPENDS` variable, the + :term:`RRECOMMENDS` variable, and the + ":ref:`bitbake-user-manual/bitbake-user-manual-metadata:runtime dependencies`" section for more + information. + +- ``[recideptask]``: When set in conjunction with ``recrdeptask``, + specifies a task that should be inspected for additional + dependencies. + +- ``[recrdeptask]``: Controls task recursive runtime dependencies. + See the :term:`RDEPENDS` variable, the + :term:`RRECOMMENDS` variable, and the + ":ref:`bitbake-user-manual/bitbake-user-manual-metadata:recursive dependencies`" section for + more information. + +- ``[stamp-extra-info]``: Extra stamp information to append to the + task's stamp. As an example, OpenEmbedded uses this flag to allow + machine-specific tasks. + +- ``[umask]``: The umask to run the task under. + +Several varflags are useful for controlling how signatures are +calculated for variables. For more information on this process, see the +":ref:`bitbake-user-manual/bitbake-user-manual-execution:checksums (signatures)`" section. + +- ``[vardeps]``: Specifies a space-separated list of additional + variables to add to a variable's dependencies for the purposes of + calculating its signature. Adding variables to this list is useful, + for example, when a function refers to a variable in a manner that + does not allow BitBake to automatically determine that the variable + is referred to. + +- ``[vardepsexclude]``: Specifies a space-separated list of variables + that should be excluded from a variable's dependencies for the + purposes of calculating its signature. + +- ``[vardepvalue]``: If set, instructs BitBake to ignore the actual + value of the variable and instead use the specified value when + calculating the variable's signature. + +- ``[vardepvalueexclude]``: Specifies a pipe-separated list of + strings to exclude from the variable's value when calculating the + variable's signature. + +Events +====== + +BitBake allows installation of event handlers within recipe and class +files. Events are triggered at certain points during operation, such as +the beginning of operation against a given recipe (i.e. ``*.bb``), the +start of a given task, a task failure, a task success, and so forth. The +intent is to make it easy to do things like email notification on build +failures. + +Following is an example event handler that prints the name of the event +and the content of the ``FILE`` variable: :: + + addhandler myclass_eventhandler + python myclass_eventhandler() { + from bb.event import getName + print("The name of the Event is %s" % getName(e)) + print("The file we run for is %s" % d.getVar('FILE')) + } + myclass_eventhandler[eventmask] = "bb.event.BuildStarted + bb.event.BuildCompleted" + +In the previous example, an eventmask has been +set so that the handler only sees the "BuildStarted" and +"BuildCompleted" events. This event handler gets called every time an +event matching the eventmask is triggered. A global variable "e" is +defined, which represents the current event. With the ``getName(e)`` +method, you can get the name of the triggered event. The global +datastore is available as "d". In legacy code, you might see "e.data" +used to get the datastore. However, realize that "e.data" is deprecated +and you should use "d" going forward. + +The context of the datastore is appropriate to the event in question. +For example, "BuildStarted" and "BuildCompleted" events run before any +tasks are executed so would be in the global configuration datastore +namespace. No recipe-specific metadata exists in that namespace. The +"BuildStarted" and "BuildCompleted" events also run in the main +cooker/server process rather than any worker context. Thus, any changes +made to the datastore would be seen by other cooker/server events within +the current build but not seen outside of that build or in any worker +context. Task events run in the actual tasks in question consequently +have recipe-specific and task-specific contents. These events run in the +worker context and are discarded at the end of task execution. + +During a standard build, the following common events might occur. The +following events are the most common kinds of events that most metadata +might have an interest in viewing: + +- ``bb.event.ConfigParsed()``: Fired when the base configuration; which + consists of ``bitbake.conf``, ``base.bbclass`` and any global + ``INHERIT`` statements; has been parsed. You can see multiple such + events when each of the workers parse the base configuration or if + the server changes configuration and reparses. Any given datastore + only has one such event executed against it, however. If + ```BB_INVALIDCONF`` <#>`__ is set in the datastore by the event + handler, the configuration is reparsed and a new event triggered, + allowing the metadata to update configuration. + +- ``bb.event.HeartbeatEvent()``: Fires at regular time intervals of one + second. You can configure the interval time using the + ``BB_HEARTBEAT_EVENT`` variable. The event's "time" attribute is the + ``time.time()`` value when the event is triggered. This event is + useful for activities such as system state monitoring. + +- ``bb.event.ParseStarted()``: Fired when BitBake is about to start + parsing recipes. This event's "total" attribute represents the number + of recipes BitBake plans to parse. + +- ``bb.event.ParseProgress()``: Fired as parsing progresses. This + event's "current" attribute is the number of recipes parsed as well + as the "total" attribute. + +- ``bb.event.ParseCompleted()``: Fired when parsing is complete. This + event's "cached", "parsed", "skipped", "virtuals", "masked", and + "errors" attributes provide statistics for the parsing results. + +- ``bb.event.BuildStarted()``: Fired when a new build starts. BitBake + fires multiple "BuildStarted" events (one per configuration) when + multiple configuration (multiconfig) is enabled. + +- ``bb.build.TaskStarted()``: Fired when a task starts. This event's + "taskfile" attribute points to the recipe from which the task + originates. The "taskname" attribute, which is the task's name, + includes the ``do_`` prefix, and the "logfile" attribute point to + where the task's output is stored. Finally, the "time" attribute is + the task's execution start time. + +- ``bb.build.TaskInvalid()``: Fired if BitBake tries to execute a task + that does not exist. + +- ``bb.build.TaskFailedSilent()``: Fired for setscene tasks that fail + and should not be presented to the user verbosely. + +- ``bb.build.TaskFailed()``: Fired for normal tasks that fail. + +- ``bb.build.TaskSucceeded()``: Fired when a task successfully + completes. + +- ``bb.event.BuildCompleted()``: Fired when a build finishes. + +- ``bb.cooker.CookerExit()``: Fired when the BitBake server/cooker + shuts down. This event is usually only seen by the UIs as a sign they + should also shutdown. + +This next list of example events occur based on specific requests to the +server. These events are often used to communicate larger pieces of +information from the BitBake server to other parts of BitBake such as +user interfaces: + +- ``bb.event.TreeDataPreparationStarted()`` +- ``bb.event.TreeDataPreparationProgress()`` +- ``bb.event.TreeDataPreparationCompleted()`` +- ``bb.event.DepTreeGenerated()`` +- ``bb.event.CoreBaseFilesFound()`` +- ``bb.event.ConfigFilePathFound()`` +- ``bb.event.FilesMatchingFound()`` +- ``bb.event.ConfigFilesFound()`` +- ``bb.event.TargetsTreeGenerated()`` + +.. _variants-class-extension-mechanism: + +Variants - Class Extension Mechanism +==================================== + +BitBake supports two features that facilitate creating from a single +recipe file multiple incarnations of that recipe file where all +incarnations are buildable. These features are enabled through the +:term:`BBCLASSEXTEND` and :term:`BBVERSIONS` variables. + +.. note:: + + The mechanism for this class extension is extremely specific to the + implementation. Usually, the recipe's :term:`PROVIDES` , :term:`PN` , and + :term:`DEPENDS` variables would need to be modified by the extension + class. For specific examples, see the OE-Core native , nativesdk , and + multilib classes. + +- ``BBCLASSEXTEND``: This variable is a space separated list of + classes used to "extend" the recipe for each variant. Here is an + example that results in a second incarnation of the current recipe + being available. This second incarnation will have the "native" class + inherited. :: + + BBCLASSEXTEND = "native" + +- ``BBVERSIONS``: This variable allows a single recipe to build + multiple versions of a project from a single recipe file. You can + also specify conditional metadata (using the + :term:`OVERRIDES` mechanism) for a single + version, or an optionally named range of versions. Here is an + example: :: + + BBVERSIONS = "1.0 2.0 git" + SRC_URI_git = "git://someurl/somepath.git" + + BBVERSIONS = "1.0.[0-6]:1.0.0+ 1.0.[7-9]:1.0.7+" + SRC_URI_append_1.0.7+ = "file://some_patch_which_the_new_versions_need.patch;patch=1" + + The name of the range defaults to the original version of the recipe. For + example, in OpenEmbedded, the recipe file ``foo_1.0.0+.bb`` creates a default + name range of ``1.0.0+``. This is useful because the range name is not only + placed into overrides, but it is also made available for the metadata to use + in the variable that defines the base recipe versions for use in ``file://`` + search paths (:term:`FILESPATH`). + +Dependencies +============ + +To allow for efficient parallel processing, BitBake handles dependencies +at the task level. Dependencies can exist both between tasks within a +single recipe and between tasks in different recipes. Following are +examples of each: + +- For tasks within a single recipe, a recipe's ``do_configure`` task + might need to complete before its ``do_compile`` task can run. + +- For tasks in different recipes, one recipe's ``do_configure`` task + might require another recipe's ``do_populate_sysroot`` task to finish + first such that the libraries and headers provided by the other + recipe are available. + +This section describes several ways to declare dependencies. Remember, +even though dependencies are declared in different ways, they are all +simply dependencies between tasks. + +.. _dependencies-internal-to-the-bb-file: + +Dependencies Internal to the ``.bb`` File +----------------------------------------- + +BitBake uses the ``addtask`` directive to manage dependencies that are +internal to a given recipe file. You can use the ``addtask`` directive +to indicate when a task is dependent on other tasks or when other tasks +depend on that recipe. Here is an example: :: + + addtask printdate after do_fetch before do_build + +In this example, the ``do_printdate`` task +depends on the completion of the ``do_fetch`` task, and the ``do_build`` +task depends on the completion of the ``do_printdate`` task. + +.. note:: + + For a task to run, it must be a direct or indirect dependency of some + other task that is scheduled to run. + + For illustration, here are some examples: + + - The directive ``addtask mytask before do_configure`` causes + ``do_mytask`` to run before ``do_configure`` runs. Be aware that + ``do_mytask`` still only runs if its :ref:`input + checksum <bitbake-user-manual/bitbake-user-manual-execution:checksums (signatures)>` has changed since the last time it was + run. Changes to the input checksum of ``do_mytask`` also + indirectly cause ``do_configure`` to run. + + - The directive ``addtask mytask after do_configure`` by itself + never causes ``do_mytask`` to run. ``do_mytask`` can still be run + manually as follows: :: + + $ bitbake recipe -c mytask + + Declaring ``do_mytask`` as a dependency of some other task that is + scheduled to run also causes it to run. Regardless, the task runs after + ``do_configure``. + +Build Dependencies +------------------ + +BitBake uses the :term:`DEPENDS` variable to manage +build time dependencies. The ``[deptask]`` varflag for tasks signifies +the task of each item listed in ``DEPENDS`` that must complete before +that task can be executed. Here is an example: :: + + do_configure[deptask] = "do_populate_sysroot" + +In this example, the ``do_populate_sysroot`` task +of each item in ``DEPENDS`` must complete before ``do_configure`` can +execute. + +Runtime Dependencies +-------------------- + +BitBake uses the :term:`PACKAGES`, :term:`RDEPENDS`, and :term:`RRECOMMENDS` +variables to manage runtime dependencies. + +The ``PACKAGES`` variable lists runtime packages. Each of those packages +can have ``RDEPENDS`` and ``RRECOMMENDS`` runtime dependencies. The +``[rdeptask]`` flag for tasks is used to signify the task of each item +runtime dependency which must have completed before that task can be +executed. :: + + do_package_qa[rdeptask] = "do_packagedata" + +In the previous +example, the ``do_packagedata`` task of each item in ``RDEPENDS`` must +have completed before ``do_package_qa`` can execute. +Although ``RDEPENDS`` contains entries from the +runtime dependency namespace, BitBake knows how to map them back +to the build-time dependency namespace, in which the tasks are defined. + +Recursive Dependencies +---------------------- + +BitBake uses the ``[recrdeptask]`` flag to manage recursive task +dependencies. BitBake looks through the build-time and runtime +dependencies of the current recipe, looks through the task's inter-task +dependencies, and then adds dependencies for the listed task. Once +BitBake has accomplished this, it recursively works through the +dependencies of those tasks. Iterative passes continue until all +dependencies are discovered and added. + +The ``[recrdeptask]`` flag is most commonly used in high-level recipes +that need to wait for some task to finish "globally". For example, +``image.bbclass`` has the following: :: + + do_rootfs[recrdeptask] += "do_packagedata" + +This statement says that the ``do_packagedata`` task of +the current recipe and all recipes reachable (by way of dependencies) +from the image recipe must run before the ``do_rootfs`` task can run. + +BitBake allows a task to recursively depend on itself by +referencing itself in the task list: :: + + do_a[recrdeptask] = "do_a do_b" + +In the same way as before, this means that the ``do_a`` +and ``do_b`` tasks of the current recipe and all +recipes reachable (by way of dependencies) from the recipe +must run before the ``do_a`` task can run. In this +case BitBake will ignore the current recipe's ``do_a`` +task circular dependency on itself. + +Inter-Task Dependencies +----------------------- + +BitBake uses the ``[depends]`` flag in a more generic form to manage +inter-task dependencies. This more generic form allows for +inter-dependency checks for specific tasks rather than checks for the +data in ``DEPENDS``. Here is an example: :: + + do_patch[depends] = "quilt-native:do_populate_sysroot" + +In this example, the ``do_populate_sysroot`` task of the target ``quilt-native`` +must have completed before the ``do_patch`` task can execute. + +The ``[rdepends]`` flag works in a similar way but takes targets in the +runtime namespace instead of the build-time dependency namespace. + +Functions You Can Call From Within Python +========================================= + +BitBake provides many functions you can call from within Python +functions. This section lists the most commonly used functions, and +mentions where to find others. + +Functions for Accessing Datastore Variables +------------------------------------------- + +It is often necessary to access variables in the BitBake datastore using +Python functions. The BitBake datastore has an API that allows you this +access. Here is a list of available operations: + +.. list-table:: + :widths: auto + :header-rows: 1 + + * - *Operation* + - *Description* + * - ``d.getVar("X", expand)`` + - Returns the value of variable "X". Using "expand=True" expands the + value. Returns "None" if the variable "X" does not exist. + * - ``d.setVar("X", "value")`` + - Sets the variable "X" to "value" + * - ``d.appendVar("X", "value")`` + - Adds "value" to the end of the variable "X". Acts like ``d.setVar("X", + "value")`` if the variable "X" does not exist. + * - ``d.prependVar("X", "value")`` + - Adds "value" to the start of the variable "X". Acts like + ``d.setVar("X","value")`` if the variable "X" does not exist. + * - ``d.delVar("X")`` + - Deletes the variable "X" from the datastore. Does nothing if the variable + "X" does not exist. + * - ``d.renameVar("X", "Y")`` + - Renames the variable "X" to "Y". Does nothing if the variable "X" does + not exist. + * - ``d.getVarFlag("X", flag, expand)`` + - Returns the value of variable "X". Using "expand=True" expands the + value. Returns "None" if either the variable "X" or the named flag does + not exist. + * - ``d.setVarFlag("X", flag, "value")`` + - Sets the named flag for variable "X" to "value". + * - ``d.appendVarFlag("X", flag, "value")`` + - Appends "value" to the named flag on the variable "X". Acts like + ``d.setVarFlag("X", flag, "value")`` if the named flag does not exist. + * - ``d.prependVarFlag("X", flag, "value")`` + - Prepends "value" to the named flag on the variable "X". Acts like + ``d.setVarFlag("X", flag, "value")`` if the named flag does not exist. + * - ``d.delVarFlag("X", flag)`` + - Deletes the named flag on the variable "X" from the datastore. + * - ``d.setVarFlags("X", flagsdict)`` + - Sets the flags specified in the ``flagsdict()`` + parameter. ``setVarFlags`` does not clear previous flags. Think of this + operation as ``addVarFlags``. + * - ``d.getVarFlags("X")`` + - Returns a ``flagsdict`` of the flags for the variable "X". Returns "None" + if the variable "X" does not exist. + * - ``d.delVarFlags("X")`` + - Deletes all the flags for the variable "X". Does nothing if the variable + "X" does not exist. + * - ``d.expand(expression)`` + - Expands variable references in the specified string + expression. References to variables that do not exist are left as is. For + example, ``d.expand("foo ${X}")`` expands to the literal string "foo + ${X}" if the variable "X" does not exist. + +Other Functions +--------------- + +You can find many other functions that can be called from Python by +looking at the source code of the ``bb`` module, which is in +``bitbake/lib/bb``. For example, ``bitbake/lib/bb/utils.py`` includes +the commonly used functions ``bb.utils.contains()`` and +``bb.utils.mkdirhier()``, which come with docstrings. + +Task Checksums and Setscene +=========================== + +BitBake uses checksums (or signatures) along with the setscene to +determine if a task needs to be run. This section describes the process. +To help understand how BitBake does this, the section assumes an +OpenEmbedded metadata-based example. + +These checksums are stored in :term:`STAMP`. You can +examine the checksums using the following BitBake command: :: + + $ bitbake-dumpsigs + +This command returns the signature data in a readable +format that allows you to examine the inputs used when the OpenEmbedded +build system generates signatures. For example, using +``bitbake-dumpsigs`` allows you to examine the ``do_compile`` task's +“sigdata” for a C application (e.g. ``bash``). Running the command also +reveals that the “CC” variable is part of the inputs that are hashed. +Any changes to this variable would invalidate the stamp and cause the +``do_compile`` task to run. + +The following list describes related variables: + +- :term:`BB_HASHCHECK_FUNCTION`: + Specifies the name of the function to call during the "setscene" part + of the task's execution in order to validate the list of task hashes. + +- :term:`BB_SETSCENE_DEPVALID`: + Specifies a function BitBake calls that determines whether BitBake + requires a setscene dependency to be met. + +- :term:`BB_SETSCENE_VERIFY_FUNCTION2`: + Specifies a function to call that verifies the list of planned task + execution before the main task execution happens. + +- :term:`BB_STAMP_POLICY`: Defines the mode + for comparing timestamps of stamp files. + +- :term:`BB_STAMP_WHITELIST`: Lists stamp + files that are looked at when the stamp policy is "whitelist". + +- :term:`BB_TASKHASH`: Within an executing task, + this variable holds the hash of the task as returned by the currently + enabled signature generator. + +- :term:`STAMP`: The base path to create stamp files. + +- :term:`STAMPCLEAN`: Again, the base path to + create stamp files but can use wildcards for matching a range of + files for clean operations. + +Wildcard Support in Variables +============================= + +Support for wildcard use in variables varies depending on the context in +which it is used. For example, some variables and file names allow +limited use of wildcards through the "``%``" and "``*``" characters. +Other variables or names support Python's +`glob <https://docs.python.org/3/library/glob.html>`_ syntax, +`fnmatch <https://docs.python.org/3/library/fnmatch.html#module-fnmatch>`_ +syntax, or +`Regular Expression (re) <https://docs.python.org/3/library/re.html>`_ +syntax. + +For variables that have wildcard suport, the documentation describes +which form of wildcard, its use, and its limitations. diff --git a/poky/bitbake/doc/bitbake-user-manual/bitbake-user-manual-metadata.xml b/poky/bitbake/doc/bitbake-user-manual/bitbake-user-manual-metadata.xml index 95a8b95b1..0ca532161 100644 --- a/poky/bitbake/doc/bitbake-user-manual/bitbake-user-manual-metadata.xml +++ b/poky/bitbake/doc/bitbake-user-manual/bitbake-user-manual-metadata.xml @@ -432,7 +432,7 @@ The variable <filename>FOO</filename> becomes " 789 123456 " and <filename>FOO2</filename> becomes - " jkl abcdef ". + " abcdef ". </para> <para> @@ -2565,15 +2565,17 @@ </para> <para> - You might want to not only have BitBake look for - dependencies of those tasks, but also have BitBake look - for build-time and runtime dependencies of the dependent - tasks as well. - If that is the case, you need to reference the task name - itself in the task list: + BitBake allows a task to recursively depend on itself by + referencing itself in the task list: <literallayout class='monospaced'> do_a[recrdeptask] = "do_a do_b" </literallayout> + In the same way as before, this means that the <filename>do_a</filename> + and <filename>do_b</filename> tasks of the current recipe and all + recipes reachable (by way of dependencies) from the recipe + must run before the <filename>do_a</filename> task can run. In this + case BitBake will ignore the current recipe's <filename>do_a</filename> + task circular dependency on itself. </para> </section> diff --git a/poky/bitbake/doc/bitbake-user-manual/bitbake-user-manual-ref-variables.rst b/poky/bitbake/doc/bitbake-user-manual/bitbake-user-manual-ref-variables.rst new file mode 100644 index 000000000..fb1b353c8 --- /dev/null +++ b/poky/bitbake/doc/bitbake-user-manual/bitbake-user-manual-ref-variables.rst @@ -0,0 +1,1372 @@ +.. SPDX-License-Identifier: CC-BY-2.5 + +================== +Variables Glossary +================== + +| + +This chapter lists common variables used by BitBake and gives an +overview of their function and contents. + +.. note:: + + Following are some points regarding the variables listed in this + glossary: + + - The variables listed in this glossary are specific to BitBake. + Consequently, the descriptions are limited to that context. + + - Also, variables exist in other systems that use BitBake (e.g. The + Yocto Project and OpenEmbedded) that have names identical to those + found in this glossary. For such cases, the variables in those + systems extend the functionality of the variable as it is + described here in this glossary. + + - Finally, there are variables mentioned in this glossary that do + not appear in the BitBake glossary. These other variables are + variables used in systems that use BitBake. + +.. glossary:: + + ASSUME_PROVIDED + Lists recipe names (:term:`PN` values) BitBake does not + attempt to build. Instead, BitBake assumes these recipes have already + been built. + + In OpenEmbedded-Core, ``ASSUME_PROVIDED`` mostly specifies native + tools that should not be built. An example is ``git-native``, which + when specified allows for the Git binary from the host to be used + rather than building ``git-native``. + + B + The directory in which BitBake executes functions during a recipe's + build process. + + BB_ALLOWED_NETWORKS + Specifies a space-delimited list of hosts that the fetcher is allowed + to use to obtain the required source code. Following are + considerations surrounding this variable: + + - This host list is only used if + :term:`BB_NO_NETWORK` is either not set or + set to "0". + + - Limited support for the "``*``" wildcard character for matching + against the beginning of host names exists. For example, the + following setting matches ``git.gnu.org``, ``ftp.gnu.org``, and + ``foo.git.gnu.org``. :: + + BB_ALLOWED_NETWORKS = "\*.gnu.org" + + .. important:: + + The use of the "``*``" character only works at the beginning of + a host name and it must be isolated from the remainder of the + host name. You cannot use the wildcard character in any other + location of the name or combined with the front part of the + name. + + For example, ``*.foo.bar`` is supported, while ``*aa.foo.bar`` + is not. + + - Mirrors not in the host list are skipped and logged in debug. + + - Attempts to access networks not in the host list cause a failure. + + Using ``BB_ALLOWED_NETWORKS`` in conjunction with + :term:`PREMIRRORS` is very useful. Adding the + host you want to use to ``PREMIRRORS`` results in the source code + being fetched from an allowed location and avoids raising an error + when a host that is not allowed is in a + :term:`SRC_URI` statement. This is because the + fetcher does not attempt to use the host listed in ``SRC_URI`` after + a successful fetch from the ``PREMIRRORS`` occurs. + + BB_CONSOLELOG + Specifies the path to a log file into which BitBake's user interface + writes output during the build. + + BB_CURRENTTASK + Contains the name of the currently running task. The name does not + include the ``do_`` prefix. + + BB_DANGLINGAPPENDS_WARNONLY + Defines how BitBake handles situations where an append file + (``.bbappend``) has no corresponding recipe file (``.bb``). This + condition often occurs when layers get out of sync (e.g. ``oe-core`` + bumps a recipe version and the old recipe no longer exists and the + other layer has not been updated to the new version of the recipe + yet). + + The default fatal behavior is safest because it is the sane reaction + given something is out of sync. It is important to realize when your + changes are no longer being applied. + + BB_DEFAULT_TASK + The default task to use when none is specified (e.g. with the ``-c`` + command line option). The task name specified should not include the + ``do_`` prefix. + + BB_DISKMON_DIRS + Monitors disk space and available inodes during the build and allows + you to control the build based on these parameters. + + Disk space monitoring is disabled by default. When setting this + variable, use the following form: :: + + BB_DISKMON_DIRS = "<action>,<dir>,<threshold> [...]" + + where: + + <action> is: + ABORT: Immediately abort the build when + a threshold is broken. + STOPTASKS: Stop the build after the currently + executing tasks have finished when + a threshold is broken. + WARN: Issue a warning but continue the + build when a threshold is broken. + Subsequent warnings are issued as + defined by the + BB_DISKMON_WARNINTERVAL variable, + which must be defined. + + <dir> is: + Any directory you choose. You can specify one or + more directories to monitor by separating the + groupings with a space. If two directories are + on the same device, only the first directory + is monitored. + + <threshold> is: + Either the minimum available disk space, + the minimum number of free inodes, or + both. You must specify at least one. To + omit one or the other, simply omit the value. + Specify the threshold using G, M, K for Gbytes, + Mbytes, and Kbytes, respectively. If you do + not specify G, M, or K, Kbytes is assumed by + default. Do not use GB, MB, or KB. + + Here are some examples: :: + + BB_DISKMON_DIRS = "ABORT,${TMPDIR},1G,100K WARN,${SSTATE_DIR},1G,100K" + BB_DISKMON_DIRS = "STOPTASKS,${TMPDIR},1G" + BB_DISKMON_DIRS = "ABORT,${TMPDIR},,100K" + + The first example works only if you also set the + :term:`BB_DISKMON_WARNINTERVAL` + variable. This example causes the build system to immediately abort + when either the disk space in ``${TMPDIR}`` drops below 1 Gbyte or + the available free inodes drops below 100 Kbytes. Because two + directories are provided with the variable, the build system also + issues a warning when the disk space in the ``${SSTATE_DIR}`` + directory drops below 1 Gbyte or the number of free inodes drops + below 100 Kbytes. Subsequent warnings are issued during intervals as + defined by the ``BB_DISKMON_WARNINTERVAL`` variable. + + The second example stops the build after all currently executing + tasks complete when the minimum disk space in the ``${TMPDIR}`` + directory drops below 1 Gbyte. No disk monitoring occurs for the free + inodes in this case. + + The final example immediately aborts the build when the number of + free inodes in the ``${TMPDIR}`` directory drops below 100 Kbytes. No + disk space monitoring for the directory itself occurs in this case. + + BB_DISKMON_WARNINTERVAL + Defines the disk space and free inode warning intervals. + + If you are going to use the ``BB_DISKMON_WARNINTERVAL`` variable, you + must also use the :term:`BB_DISKMON_DIRS` + variable and define its action as "WARN". During the build, + subsequent warnings are issued each time disk space or number of free + inodes further reduces by the respective interval. + + If you do not provide a ``BB_DISKMON_WARNINTERVAL`` variable and you + do use ``BB_DISKMON_DIRS`` with the "WARN" action, the disk + monitoring interval defaults to the following: + BB_DISKMON_WARNINTERVAL = "50M,5K" + + When specifying the variable in your configuration file, use the + following form: :: + + BB_DISKMON_WARNINTERVAL = "<disk_space_interval>,<disk_inode_interval>" + + where: + + <disk_space_interval> is: + An interval of memory expressed in either + G, M, or K for Gbytes, Mbytes, or Kbytes, + respectively. You cannot use GB, MB, or KB. + + <disk_inode_interval> is: + An interval of free inodes expressed in either + G, M, or K for Gbytes, Mbytes, or Kbytes, + respectively. You cannot use GB, MB, or KB. + + Here is an example: :: + + BB_DISKMON_DIRS = "WARN,${SSTATE_DIR},1G,100K" + BB_DISKMON_WARNINTERVAL = "50M,5K" + + These variables cause BitBake to + issue subsequent warnings each time the available disk space further + reduces by 50 Mbytes or the number of free inodes further reduces by + 5 Kbytes in the ``${SSTATE_DIR}`` directory. Subsequent warnings + based on the interval occur each time a respective interval is + reached beyond the initial warning (i.e. 1 Gbytes and 100 Kbytes). + + BB_ENV_WHITELIST + Specifies the internal whitelist of variables to allow through from + the external environment into BitBake's datastore. If the value of + this variable is not specified (which is the default), the following + list is used: :term:`BBPATH`, :term:`BB_PRESERVE_ENV`, + :term:`BB_ENV_WHITELIST`, and :term:`BB_ENV_EXTRAWHITE`. + + .. note:: + + You must set this variable in the external environment in order + for it to work. + + BB_ENV_EXTRAWHITE + Specifies an additional set of variables to allow through (whitelist) + from the external environment into BitBake's datastore. This list of + variables are on top of the internal list set in + :term:`BB_ENV_WHITELIST`. + + .. note:: + + You must set this variable in the external environment in order + for it to work. + + BB_FETCH_PREMIRRORONLY + When set to "1", causes BitBake's fetcher module to only search + :term:`PREMIRRORS` for files. BitBake will not + search the main :term:`SRC_URI` or + :term:`MIRRORS`. + + BB_FILENAME + Contains the filename of the recipe that owns the currently running + task. For example, if the ``do_fetch`` task that resides in the + ``my-recipe.bb`` is executing, the ``BB_FILENAME`` variable contains + "/foo/path/my-recipe.bb". + + BBFILES_DYNAMIC + Activates content depending on presence of identified layers. You + identify the layers by the collections that the layers define. + + Use the ``BBFILES_DYNAMIC`` variable to avoid ``.bbappend`` files whose + corresponding ``.bb`` file is in a layer that attempts to modify other + layers through ``.bbappend`` but does not want to introduce a hard + dependency on those other layers. + + Additionally you can prefix the rule with "!" to add ``.bbappend`` and + ``.bb`` files in case a layer is not present. Use this avoid hard + dependency on those other layers. + + Use the following form for ``BBFILES_DYNAMIC``: :: + + collection_name:filename_pattern + + The following example identifies two collection names and two filename + patterns: :: + + BBFILES_DYNAMIC += "\ + clang-layer:${LAYERDIR}/bbappends/meta-clang/*/*/*.bbappend \ + core:${LAYERDIR}/bbappends/openembedded-core/meta/*/*/*.bbappend \ + " + + When the collection name is prefixed with "!" it will add the file pattern in case + the layer is absent: :: + + BBFILES_DYNAMIC += "\ + !clang-layer:${LAYERDIR}/backfill/meta-clang/*/*/*.bb \ + " + + This next example shows an error message that occurs because invalid + entries are found, which cause parsing to abort: :: + + ERROR: BBFILES_DYNAMIC entries must be of the form {!}<collection name>:<filename pattern>, not: + /work/my-layer/bbappends/meta-security-isafw/*/*/*.bbappend + /work/my-layer/bbappends/openembedded-core/meta/*/*/*.bbappend + + BB_GENERATE_MIRROR_TARBALLS + Causes tarballs of the Git repositories, including the Git metadata, + to be placed in the :term:`DL_DIR` directory. Anyone + wishing to create a source mirror would want to enable this variable. + + For performance reasons, creating and placing tarballs of the Git + repositories is not the default action by BitBake. :: + + BB_GENERATE_MIRROR_TARBALLS = "1" + + BB_HASHCONFIG_WHITELIST + Lists variables that are excluded from base configuration checksum, + which is used to determine if the cache can be reused. + + One of the ways BitBake determines whether to re-parse the main + metadata is through checksums of the variables in the datastore of + the base configuration data. There are variables that you typically + want to exclude when checking whether or not to re-parse and thus + rebuild the cache. As an example, you would usually exclude ``TIME`` + and ``DATE`` because these variables are always changing. If you did + not exclude them, BitBake would never reuse the cache. + + BB_HASHBASE_WHITELIST + Lists variables that are excluded from checksum and dependency data. + Variables that are excluded can therefore change without affecting + the checksum mechanism. A common example would be the variable for + the path of the build. BitBake's output should not (and usually does + not) depend on the directory in which it was built. + + BB_HASHCHECK_FUNCTION + Specifies the name of the function to call during the "setscene" part + of the task's execution in order to validate the list of task hashes. + The function returns the list of setscene tasks that should be + executed. + + At this point in the execution of the code, the objective is to + quickly verify if a given setscene function is likely to work or not. + It's easier to check the list of setscene functions in one pass than + to call many individual tasks. The returned list need not be + completely accurate. A given setscene task can still later fail. + However, the more accurate the data returned, the more efficient the + build will be. + + BB_INVALIDCONF + Used in combination with the ``ConfigParsed`` event to trigger + re-parsing the base metadata (i.e. all the recipes). The + ``ConfigParsed`` event can set the variable to trigger the re-parse. + You must be careful to avoid recursive loops with this functionality. + + BB_LOGCONFIG + Specifies the name of a config file that contains the user logging + configuration. See + :ref:`bitbake-user-manual/bitbake-user-manual-execution:logging` + for additional information + + BB_LOGFMT + Specifies the name of the log files saved into + ``${``\ :term:`T`\ ``}``. By default, the ``BB_LOGFMT`` + variable is undefined and the log file names get created using the + following form: :: + + log.{task}.{pid} + + If you want to force log files to take a specific name, you can set this + variable in a configuration file. + + BB_NICE_LEVEL + Allows BitBake to run at a specific priority (i.e. nice level). + System permissions usually mean that BitBake can reduce its priority + but not raise it again. See :term:`BB_TASK_NICE_LEVEL` for + additional information. + + BB_NO_NETWORK + Disables network access in the BitBake fetcher modules. With this + access disabled, any command that attempts to access the network + becomes an error. + + Disabling network access is useful for testing source mirrors, + running builds when not connected to the Internet, and when operating + in certain kinds of firewall environments. + + BB_NUMBER_THREADS + The maximum number of tasks BitBake should run in parallel at any one + time. If your host development system supports multiple cores, a good + rule of thumb is to set this variable to twice the number of cores. + + BB_NUMBER_PARSE_THREADS + Sets the number of threads BitBake uses when parsing. By default, the + number of threads is equal to the number of cores on the system. + + BB_ORIGENV + Contains a copy of the original external environment in which BitBake + was run. The copy is taken before any whitelisted variable values are + filtered into BitBake's datastore. + + .. note:: + + The contents of this variable is a datastore object that can be + queried using the normal datastore operations. + + BB_PRESERVE_ENV + Disables whitelisting and instead allows all variables through from + the external environment into BitBake's datastore. + + .. note:: + + You must set this variable in the external environment in order + for it to work. + + BB_RUNFMT + Specifies the name of the executable script files (i.e. run files) + saved into ``${``\ :term:`T`\ ``}``. By default, the + ``BB_RUNFMT`` variable is undefined and the run file names get + created using the following form: :: + + run.{task}.{pid} + + If you want to force run files to take a specific name, you can set this + variable in a configuration file. + + BB_RUNTASK + Contains the name of the currently executing task. The value includes + the "do\_" prefix. For example, if the currently executing task is + ``do_config``, the value is "do_config". + + BB_SCHEDULER + Selects the name of the scheduler to use for the scheduling of + BitBake tasks. Three options exist: + + - *basic* - The basic framework from which everything derives. Using + this option causes tasks to be ordered numerically as they are + parsed. + + - *speed* - Executes tasks first that have more tasks depending on + them. The "speed" option is the default. + + - *completion* - Causes the scheduler to try to complete a given + recipe once its build has started. + + BB_SCHEDULERS + Defines custom schedulers to import. Custom schedulers need to be + derived from the ``RunQueueScheduler`` class. + + For information how to select a scheduler, see the + :term:`BB_SCHEDULER` variable. + + BB_SETSCENE_DEPVALID + Specifies a function BitBake calls that determines whether BitBake + requires a setscene dependency to be met. + + When running a setscene task, BitBake needs to know which + dependencies of that setscene task also need to be run. Whether + dependencies also need to be run is highly dependent on the metadata. + The function specified by this variable returns a "True" or "False" + depending on whether the dependency needs to be met. + + BB_SETSCENE_VERIFY_FUNCTION2 + Specifies a function to call that verifies the list of planned task + execution before the main task execution happens. The function is + called once BitBake has a list of setscene tasks that have run and + either succeeded or failed. + + The function allows for a task list check to see if they make sense. + Even if BitBake was planning to skip a task, the returned value of + the function can force BitBake to run the task, which is necessary + under certain metadata defined circumstances. + + BB_SIGNATURE_EXCLUDE_FLAGS + Lists variable flags (varflags) that can be safely excluded from + checksum and dependency data for keys in the datastore. When + generating checksum or dependency data for keys in the datastore, the + flags set against that key are normally included in the checksum. + + For more information on varflags, see the + ":ref:`bitbake-user-manual/bitbake-user-manual-metadata:variable flags`" + section. + + BB_SIGNATURE_HANDLER + Defines the name of the signature handler BitBake uses. The signature + handler defines the way stamp files are created and handled, if and + how the signature is incorporated into the stamps, and how the + signature itself is generated. + + A new signature handler can be added by injecting a class derived + from the ``SignatureGenerator`` class into the global namespace. + + BB_SRCREV_POLICY + Defines the behavior of the fetcher when it interacts with source + control systems and dynamic source revisions. The + ``BB_SRCREV_POLICY`` variable is useful when working without a + network. + + The variable can be set using one of two policies: + + - *cache* - Retains the value the system obtained previously rather + than querying the source control system each time. + + - *clear* - Queries the source controls system every time. With this + policy, there is no cache. The "clear" policy is the default. + + BB_STAMP_POLICY + Defines the mode used for how timestamps of stamp files are compared. + You can set the variable to one of the following modes: + + - *perfile* - Timestamp comparisons are only made between timestamps + of a specific recipe. This is the default mode. + + - *full* - Timestamp comparisons are made for all dependencies. + + - *whitelist* - Identical to "full" mode except timestamp + comparisons are made for recipes listed in the + :term:`BB_STAMP_WHITELIST` variable. + + .. note:: + + Stamp policies are largely obsolete with the introduction of + setscene tasks. + + BB_STAMP_WHITELIST + Lists files whose stamp file timestamps are compared when the stamp + policy mode is set to "whitelist". For information on stamp policies, + see the :term:`BB_STAMP_POLICY` variable. + + BB_STRICT_CHECKSUM + Sets a more strict checksum mechanism for non-local URLs. Setting + this variable to a value causes BitBake to report an error if it + encounters a non-local URL that does not have at least one checksum + specified. + + BB_TASK_IONICE_LEVEL + Allows adjustment of a task's Input/Output priority. During + Autobuilder testing, random failures can occur for tasks due to I/O + starvation. These failures occur during various QEMU runtime + timeouts. You can use the ``BB_TASK_IONICE_LEVEL`` variable to adjust + the I/O priority of these tasks. + + .. note:: + + This variable works similarly to the :term:`BB_TASK_NICE_LEVEL` + variable except with a task's I/O priorities. + + Set the variable as follows: :: + + BB_TASK_IONICE_LEVEL = "class.prio" + + For *class*, the default value is "2", which is a best effort. You can use + "1" for realtime and "3" for idle. If you want to use realtime, you + must have superuser privileges. + + For *prio*, you can use any value from "0", which is the highest + priority, to "7", which is the lowest. The default value is "4". You + do not need any special privileges to use this range of priority + values. + + .. note:: + + In order for your I/O priority settings to take effect, you need the + Completely Fair Queuing (CFQ) Scheduler selected for the backing block + device. To select the scheduler, use the following command form where + device is the device (e.g. sda, sdb, and so forth): :: + + $ sudo sh -c “echo cfq > /sys/block/device/queu/scheduler + + BB_TASK_NICE_LEVEL + Allows specific tasks to change their priority (i.e. nice level). + + You can use this variable in combination with task overrides to raise + or lower priorities of specific tasks. For example, on the `Yocto + Project <http://www.yoctoproject.org>`__ autobuilder, QEMU emulation + in images is given a higher priority as compared to build tasks to + ensure that images do not suffer timeouts on loaded systems. + + BB_TASKHASH + Within an executing task, this variable holds the hash of the task as + returned by the currently enabled signature generator. + + BB_VERBOSE_LOGS + Controls how verbose BitBake is during builds. If set, shell scripts + echo commands and shell script output appears on standard out + (stdout). + + BB_WORKERCONTEXT + Specifies if the current context is executing a task. BitBake sets + this variable to "1" when a task is being executed. The value is not + set when the task is in server context during parsing or event + handling. + + BBCLASSEXTEND + Allows you to extend a recipe so that it builds variants of the + software. Some examples of these variants for recipes from the + OpenEmbedded-Core metadata are "natives" such as ``quilt-native``, + which is a copy of Quilt built to run on the build system; "crosses" + such as ``gcc-cross``, which is a compiler built to run on the build + machine but produces binaries that run on the target ``MACHINE``; + "nativesdk", which targets the SDK machine instead of ``MACHINE``; + and "mulitlibs" in the form "``multilib:``\ multilib_name". + + To build a different variant of the recipe with a minimal amount of + code, it usually is as simple as adding the variable to your recipe. + Here are two examples. The "native" variants are from the + OpenEmbedded-Core metadata: :: + + BBCLASSEXTEND =+ "native nativesdk" + BBCLASSEXTEND =+ "multilib:multilib_name" + + .. note:: + + Internally, the ``BBCLASSEXTEND`` mechanism generates recipe + variants by rewriting variable values and applying overrides such + as ``_class-native``. For example, to generate a native version of + a recipe, a :term:`DEPENDS` on "foo" is + rewritten to a ``DEPENDS`` on "foo-native". + + Even when using ``BBCLASSEXTEND``, the recipe is only parsed once. + Parsing once adds some limitations. For example, it is not + possible to include a different file depending on the variant, + since ``include`` statements are processed when the recipe is + parsed. + + BBDEBUG + Sets the BitBake debug output level to a specific value as + incremented by the ``-D`` command line option. + + .. note:: + + You must set this variable in the external environment in order + for it to work. + + BBFILE_COLLECTIONS + Lists the names of configured layers. These names are used to find + the other ``BBFILE_*`` variables. Typically, each layer appends its + name to this variable in its ``conf/layer.conf`` file. + + BBFILE_PATTERN + Variable that expands to match files from + :term:`BBFILES` in a particular layer. This + variable is used in the ``conf/layer.conf`` file and must be suffixed + with the name of the specific layer (e.g. + ``BBFILE_PATTERN_emenlow``). + + BBFILE_PRIORITY + Assigns the priority for recipe files in each layer. + + This variable is useful in situations where the same recipe appears + in more than one layer. Setting this variable allows you to + prioritize a layer against other layers that contain the same recipe + - effectively letting you control the precedence for the multiple + layers. The precedence established through this variable stands + regardless of a recipe's version (:term:`PV` variable). + For example, a layer that has a recipe with a higher ``PV`` value but + for which the ``BBFILE_PRIORITY`` is set to have a lower precedence + still has a lower precedence. + + A larger value for the ``BBFILE_PRIORITY`` variable results in a + higher precedence. For example, the value 6 has a higher precedence + than the value 5. If not specified, the ``BBFILE_PRIORITY`` variable + is set based on layer dependencies (see the ``LAYERDEPENDS`` variable + for more information. The default priority, if unspecified for a + layer with no dependencies, is the lowest defined priority + 1 (or 1 + if no priorities are defined). + + .. tip:: + + You can use the command bitbake-layers show-layers to list all + configured layers along with their priorities. + + BBFILES + A space-separated list of recipe files BitBake uses to build + software. + + When specifying recipe files, you can pattern match using Python's + `glob <https://docs.python.org/3/library/glob.html>`_ syntax. + For details on the syntax, see the documentation by following the + previous link. + + BBINCLUDED + Contains a space-separated list of all of all files that BitBake's + parser included during parsing of the current file. + + BBINCLUDELOGS + If set to a value, enables printing the task log when reporting a + failed task. + + BBINCLUDELOGS_LINES + If :term:`BBINCLUDELOGS` is set, specifies + the maximum number of lines from the task log file to print when + reporting a failed task. If you do not set ``BBINCLUDELOGS_LINES``, + the entire log is printed. + + BBLAYERS + Lists the layers to enable during the build. This variable is defined + in the ``bblayers.conf`` configuration file in the build directory. + Here is an example: :: + + BBLAYERS = " \ + /home/scottrif/poky/meta \ + /home/scottrif/poky/meta-yocto \ + /home/scottrif/poky/meta-yocto-bsp \ + /home/scottrif/poky/meta-mykernel \ + " + + This example enables four layers, one of which is a custom, user-defined + layer named ``meta-mykernel``. + + BBLAYERS_FETCH_DIR + Sets the base location where layers are stored. This setting is used + in conjunction with ``bitbake-layers layerindex-fetch`` and tells + ``bitbake-layers`` where to place the fetched layers. + + BBMASK + Prevents BitBake from processing recipes and recipe append files. + + You can use the ``BBMASK`` variable to "hide" these ``.bb`` and + ``.bbappend`` files. BitBake ignores any recipe or recipe append + files that match any of the expressions. It is as if BitBake does not + see them at all. Consequently, matching files are not parsed or + otherwise used by BitBake. + + The values you provide are passed to Python's regular expression + compiler. Consequently, the syntax follows Python's Regular + Expression (re) syntax. The expressions are compared against the full + paths to the files. For complete syntax information, see Python's + documentation at http://docs.python.org/3/library/re.html. + + The following example uses a complete regular expression to tell + BitBake to ignore all recipe and recipe append files in the + ``meta-ti/recipes-misc/`` directory: :: + + BBMASK = "meta-ti/recipes-misc/" + + If you want to mask out multiple directories or recipes, you can + specify multiple regular expression fragments. This next example + masks out multiple directories and individual recipes: :: + + BBMASK += "/meta-ti/recipes-misc/ meta-ti/recipes-ti/packagegroup/" + BBMASK += "/meta-oe/recipes-support/" + BBMASK += "/meta-foo/.*/openldap" + BBMASK += "opencv.*\.bbappend" + BBMASK += "lzma" + + .. note:: + + When specifying a directory name, use the trailing slash character + to ensure you match just that directory name. + + BBMULTICONFIG + Enables BitBake to perform multiple configuration builds and lists + each separate configuration (multiconfig). You can use this variable + to cause BitBake to build multiple targets where each target has a + separate configuration. Define ``BBMULTICONFIG`` in your + ``conf/local.conf`` configuration file. + + As an example, the following line specifies three multiconfigs, each + having a separate configuration file: :: + + BBMULTIFONFIG = "configA configB configC" + + Each configuration file you use must reside in the + build directory within a directory named ``conf/multiconfig`` (e.g. + build_directory\ ``/conf/multiconfig/configA.conf``). + + For information on how to use ``BBMULTICONFIG`` in an environment + that supports building targets with multiple configurations, see the + ":ref:`bitbake-user-manual/bitbake-user-manual-intro:executing a multiple configuration build`" + section. + + BBPATH + Used by BitBake to locate class (``.bbclass``) and configuration + (``.conf``) files. This variable is analogous to the ``PATH`` + variable. + + If you run BitBake from a directory outside of the build directory, + you must be sure to set ``BBPATH`` to point to the build directory. + Set the variable as you would any environment variable and then run + BitBake: :: + + $ BBPATH="build_directory" + $ export BBPATH + $ bitbake target + + BBSERVER + Points to the server that runs memory-resident BitBake. The variable + is only used when you employ memory-resident BitBake. + + BBTARGETS + Allows you to use a configuration file to add to the list of + command-line target recipes you want to build. + + BBVERSIONS + Allows a single recipe to build multiple versions of a project from a + single recipe file. You also able to specify conditional metadata + using the :term:`OVERRIDES` mechanism for a + single version or for an optionally named range of versions. + + For more information on ``BBVERSIONS``, see the + ":ref:`bitbake-user-manual/bitbake-user-manual-metadata:variants - class extension mechanism`" + section. + + BITBAKE_UI + Used to specify the UI module to use when running BitBake. Using this + variable is equivalent to using the ``-u`` command-line option. + + .. note:: + + You must set this variable in the external environment in order + for it to work. + + BUILDNAME + A name assigned to the build. The name defaults to a datetime stamp + of when the build was started but can be defined by the metadata. + + BZRDIR + The directory in which files checked out of a Bazaar system are + stored. + + CACHE + Specifies the directory BitBake uses to store a cache of the metadata + so it does not need to be parsed every time BitBake is started. + + CVSDIR + The directory in which files checked out under the CVS system are + stored. + + DEFAULT_PREFERENCE + Specifies a weak bias for recipe selection priority. + + The most common usage of this is variable is to set it to "-1" within + a recipe for a development version of a piece of software. Using the + variable in this way causes the stable version of the recipe to build + by default in the absence of ``PREFERRED_VERSION`` being used to + build the development version. + + .. note:: + + The bias provided by DEFAULT_PREFERENCE is weak and is overridden by + :term:`BBFILE_PRIORITY` if that variable is different between two + layers that contain different versions of the same recipe. + + DEPENDS + Lists a recipe's build-time dependencies (i.e. other recipe files). + + Consider this simple example for two recipes named "a" and "b" that + produce similarly named packages. In this example, the ``DEPENDS`` + statement appears in the "a" recipe: :: + + DEPENDS = "b" + + Here, the dependency is such that the ``do_configure`` task for recipe "a" + depends on the ``do_populate_sysroot`` task of recipe "b". This means + anything that recipe "b" puts into sysroot is available when recipe "a" is + configuring itself. + + For information on runtime dependencies, see the :term:`RDEPENDS` + variable. + + DESCRIPTION + A long description for the recipe. + + DL_DIR + The central download directory used by the build process to store + downloads. By default, ``DL_DIR`` gets files suitable for mirroring for + everything except Git repositories. If you want tarballs of Git + repositories, use the :term:`BB_GENERATE_MIRROR_TARBALLS` variable. + + EXCLUDE_FROM_WORLD + Directs BitBake to exclude a recipe from world builds (i.e. + ``bitbake world``). During world builds, BitBake locates, parses and + builds all recipes found in every layer exposed in the + ``bblayers.conf`` configuration file. + + To exclude a recipe from a world build using this variable, set the + variable to "1" in the recipe. + + .. note:: + + Recipes added to ``EXCLUDE_FROM_WORLD`` may still be built during a world + build in order to satisfy dependencies of other recipes. Adding a + recipe to ``EXCLUDE_FROM_WORLD`` only ensures that the recipe is not + explicitly added to the list of build targets in a world build. + + FAKEROOT + Contains the command to use when running a shell script in a fakeroot + environment. The ``FAKEROOT`` variable is obsolete and has been + replaced by the other ``FAKEROOT*`` variables. See these entries in + the glossary for more information. + + FAKEROOTBASEENV + Lists environment variables to set when executing the command defined + by :term:`FAKEROOTCMD` that starts the + bitbake-worker process in the fakeroot environment. + + FAKEROOTCMD + Contains the command that starts the bitbake-worker process in the + fakeroot environment. + + FAKEROOTDIRS + Lists directories to create before running a task in the fakeroot + environment. + + FAKEROOTENV + Lists environment variables to set when running a task in the + fakeroot environment. For additional information on environment + variables and the fakeroot environment, see the + :term:`FAKEROOTBASEENV` variable. + + FAKEROOTNOENV + Lists environment variables to set when running a task that is not in + the fakeroot environment. For additional information on environment + variables and the fakeroot environment, see the + :term:`FAKEROOTENV` variable. + + FETCHCMD + Defines the command the BitBake fetcher module executes when running + fetch operations. You need to use an override suffix when you use the + variable (e.g. ``FETCHCMD_git`` or ``FETCHCMD_svn``). + + FILE + Points at the current file. BitBake sets this variable during the + parsing process to identify the file being parsed. BitBake also sets + this variable when a recipe is being executed to identify the recipe + file. + + FILESPATH + Specifies directories BitBake uses when searching for patches and + files. The "local" fetcher module uses these directories when + handling ``file://`` URLs. The variable behaves like a shell ``PATH`` + environment variable. The value is a colon-separated list of + directories that are searched left-to-right in order. + + GITDIR + The directory in which a local copy of a Git repository is stored + when it is cloned. + + HGDIR + The directory in which files checked out of a Mercurial system are + stored. + + HOMEPAGE + Website where more information about the software the recipe is + building can be found. + + INHERIT + Causes the named class or classes to be inherited globally. Anonymous + functions in the class or classes are not executed for the base + configuration and in each individual recipe. The OpenEmbedded build + system ignores changes to ``INHERIT`` in individual recipes. + + For more information on ``INHERIT``, see the + ":ref:`bitbake-user-manual/bitbake-user-manual-metadata:\`\`inherit\`\` configuration directive`" + section. + + LAYERDEPENDS + Lists the layers, separated by spaces, upon which this recipe + depends. Optionally, you can specify a specific layer version for a + dependency by adding it to the end of the layer name with a colon, + (e.g. "anotherlayer:3" to be compared against + :term:`LAYERVERSION`\ ``_anotherlayer`` in + this case). BitBake produces an error if any dependency is missing or + the version numbers do not match exactly (if specified). + + You use this variable in the ``conf/layer.conf`` file. You must also + use the specific layer name as a suffix to the variable (e.g. + ``LAYERDEPENDS_mylayer``). + + LAYERDIR + When used inside the ``layer.conf`` configuration file, this variable + provides the path of the current layer. This variable is not + available outside of ``layer.conf`` and references are expanded + immediately when parsing of the file completes. + + LAYERDIR_RE + When used inside the ``layer.conf`` configuration file, this variable + provides the path of the current layer, escaped for use in a regular + expression (:term:`BBFILE_PATTERN`). This + variable is not available outside of ``layer.conf`` and references + are expanded immediately when parsing of the file completes. + + LAYERVERSION + Optionally specifies the version of a layer as a single number. You + can use this variable within + :term:`LAYERDEPENDS` for another layer in + order to depend on a specific version of the layer. + + You use this variable in the ``conf/layer.conf`` file. You must also + use the specific layer name as a suffix to the variable (e.g. + ``LAYERDEPENDS_mylayer``). + + LICENSE + The list of source licenses for the recipe. + + MIRRORS + Specifies additional paths from which BitBake gets source code. When + the build system searches for source code, it first tries the local + download directory. If that location fails, the build system tries + locations defined by :term:`PREMIRRORS`, the + upstream source, and then locations specified by ``MIRRORS`` in that + order. + + MULTI_PROVIDER_WHITELIST + Allows you to suppress BitBake warnings caused when building two + separate recipes that provide the same output. + + BitBake normally issues a warning when building two different recipes + where each provides the same output. This scenario is usually + something the user does not want. However, cases do exist where it + makes sense, particularly in the ``virtual/*`` namespace. You can use + this variable to suppress BitBake's warnings. + + To use the variable, list provider names (e.g. recipe names, + ``virtual/kernel``, and so forth). + + OVERRIDES + BitBake uses ``OVERRIDES`` to control what variables are overridden + after BitBake parses recipes and configuration files. + + Following is a simple example that uses an overrides list based on + machine architectures: OVERRIDES = "arm:x86:mips:powerpc" You can + find information on how to use ``OVERRIDES`` in the + ":ref:`bitbake-user-manual/bitbake-user-manual-metadata:conditional syntax + (overrides)`" section. + + P4DIR + The directory in which a local copy of a Perforce depot is stored + when it is fetched. + + PACKAGES + The list of packages the recipe creates. + + PACKAGES_DYNAMIC + A promise that your recipe satisfies runtime dependencies for + optional modules that are found in other recipes. + ``PACKAGES_DYNAMIC`` does not actually satisfy the dependencies, it + only states that they should be satisfied. For example, if a hard, + runtime dependency (:term:`RDEPENDS`) of another + package is satisfied during the build through the + ``PACKAGES_DYNAMIC`` variable, but a package with the module name is + never actually produced, then the other package will be broken. + + PE + The epoch of the recipe. By default, this variable is unset. The + variable is used to make upgrades possible when the versioning scheme + changes in some backwards incompatible way. + + PERSISTENT_DIR + Specifies the directory BitBake uses to store data that should be + preserved between builds. In particular, the data stored is the data + that uses BitBake's persistent data API and the data used by the PR + Server and PR Service. + + PF + Specifies the recipe or package name and includes all version and + revision numbers (i.e. ``eglibc-2.13-r20+svnr15508/`` and + ``bash-4.2-r1/``). + + PN + The recipe name. + + PR + The revision of the recipe. + + PREFERRED_PROVIDER + Determines which recipe should be given preference when multiple + recipes provide the same item. You should always suffix the variable + with the name of the provided item, and you should set it to the + :term:`PN` of the recipe to which you want to give + precedence. Some examples: :: + + PREFERRED_PROVIDER_virtual/kernel ?= "linux-yocto" + PREFERRED_PROVIDER_virtual/xserver = "xserver-xf86" + PREFERRED_PROVIDER_virtual/libgl ?= "mesa" + + PREFERRED_PROVIDERS + Determines which recipe should be given preference for cases where + multiple recipes provide the same item. Functionally, + ``PREFERRED_PROVIDERS`` is identical to + :term:`PREFERRED_PROVIDER`. However, the ``PREFERRED_PROVIDERS`` variable + lets you define preferences for multiple situations using the following + form: :: + + PREFERRED_PROVIDERS = "xxx:yyy aaa:bbb ..." + + This form is a convenient replacement for the following: :: + + PREFERRED_PROVIDER_xxx = "yyy" + PREFERRED_PROVIDER_aaa = "bbb" + + PREFERRED_VERSION + If there are multiple versions of recipes available, this variable + determines which recipe should be given preference. You must always + suffix the variable with the :term:`PN` you want to + select, and you should set :term:`PV` accordingly for + precedence. + + The ``PREFERRED_VERSION`` variable supports limited wildcard use + through the "``%``" character. You can use the character to match any + number of characters, which can be useful when specifying versions + that contain long revision numbers that potentially change. Here are + two examples: :: + + PREFERRED_VERSION_python = "2.7.3" + PREFERRED_VERSION_linux-yocto = "4.12%" + + .. important:: + + The use of the " % " character is limited in that it only works at the + end of the string. You cannot use the wildcard character in any other + location of the string. + + PREMIRRORS + Specifies additional paths from which BitBake gets source code. When + the build system searches for source code, it first tries the local + download directory. If that location fails, the build system tries + locations defined by ``PREMIRRORS``, the upstream source, and then + locations specified by :term:`MIRRORS` in that order. + + Typically, you would add a specific server for the build system to + attempt before any others by adding something like the following to + your configuration: :: + + PREMIRRORS_prepend = "\ + git://.*/.* http://www.yoctoproject.org/sources/ \n \ + ftp://.*/.* http://www.yoctoproject.org/sources/ \n \ + http://.*/.* http://www.yoctoproject.org/sources/ \n \ + https://.*/.* http://www.yoctoproject.org/sources/ \n" + + These changes cause the build system to intercept Git, FTP, HTTP, and + HTTPS requests and direct them to the ``http://`` sources mirror. You can + use ``file://`` URLs to point to local directories or network shares as + well. + + PROVIDES + A list of aliases by which a particular recipe can be known. By + default, a recipe's own ``PN`` is implicitly already in its + ``PROVIDES`` list. If a recipe uses ``PROVIDES``, the additional + aliases are synonyms for the recipe and can be useful satisfying + dependencies of other recipes during the build as specified by + ``DEPENDS``. + + Consider the following example ``PROVIDES`` statement from a recipe + file ``libav_0.8.11.bb``: :: + + PROVIDES += "libpostproc" + + The ``PROVIDES`` statement results in the "libav" recipe also being known + as "libpostproc". + + In addition to providing recipes under alternate names, the + ``PROVIDES`` mechanism is also used to implement virtual targets. A + virtual target is a name that corresponds to some particular + functionality (e.g. a Linux kernel). Recipes that provide the + functionality in question list the virtual target in ``PROVIDES``. + Recipes that depend on the functionality in question can include the + virtual target in :term:`DEPENDS` to leave the + choice of provider open. + + Conventionally, virtual targets have names on the form + "virtual/function" (e.g. "virtual/kernel"). The slash is simply part + of the name and has no syntactical significance. + + PRSERV_HOST + The network based :term:`PR` service host and port. + + Following is an example of how the ``PRSERV_HOST`` variable is set: :: + + PRSERV_HOST = "localhost:0" + + You must set the variable if you want to automatically start a local PR + service. You can set ``PRSERV_HOST`` to other values to use a remote PR + service. + + PV + The version of the recipe. + + RDEPENDS + Lists a package's runtime dependencies (i.e. other packages) that + must be installed in order for the built package to run correctly. If + a package in this list cannot be found during the build, you will get + a build error. + + Because the ``RDEPENDS`` variable applies to packages being built, + you should always use the variable in a form with an attached package + name. For example, suppose you are building a development package + that depends on the ``perl`` package. In this case, you would use the + following ``RDEPENDS`` statement: :: + + RDEPENDS_${PN}-dev += "perl" + + In the example, the development package depends on the ``perl`` package. + Thus, the ``RDEPENDS`` variable has the ``${PN}-dev`` package name as part + of the variable. + + BitBake supports specifying versioned dependencies. Although the + syntax varies depending on the packaging format, BitBake hides these + differences from you. Here is the general syntax to specify versions + with the ``RDEPENDS`` variable: :: + + RDEPENDS_${PN} = "package (operator version)" + + For ``operator``, you can specify the following: :: + + = + < + > + <= + >= + + For example, the following sets up a dependency on version 1.2 or + greater of the package ``foo``: :: + + RDEPENDS_${PN} = "foo (>= 1.2)" + + For information on build-time dependencies, see the :term:`DEPENDS` + variable. + + REPODIR + The directory in which a local copy of a ``google-repo`` directory is + stored when it is synced. + + RPROVIDES + A list of package name aliases that a package also provides. These + aliases are useful for satisfying runtime dependencies of other + packages both during the build and on the target (as specified by + ``RDEPENDS``). + + As with all package-controlling variables, you must always use the + variable in conjunction with a package name override. Here is an + example: :: + + RPROVIDES_${PN} = "widget-abi-2" + + RRECOMMENDS + A list of packages that extends the usability of a package being + built. The package being built does not depend on this list of + packages in order to successfully build, but needs them for the + extended usability. To specify runtime dependencies for packages, see + the ``RDEPENDS`` variable. + + BitBake supports specifying versioned recommends. Although the syntax + varies depending on the packaging format, BitBake hides these + differences from you. Here is the general syntax to specify versions + with the ``RRECOMMENDS`` variable: :: + + RRECOMMENDS_${PN} = "package (operator version)" + + For ``operator``, you can specify the following: :: + + = + < + > + <= + >= + + For example, the following sets up a recommend on version + 1.2 or greater of the package ``foo``: :: + + RRECOMMENDS_${PN} = "foo (>= 1.2)" + + SECTION + The section in which packages should be categorized. + + SRC_URI + The list of source files - local or remote. This variable tells + BitBake which bits to pull for the build and how to pull them. For + example, if the recipe or append file needs to fetch a single tarball + from the Internet, the recipe or append file uses a ``SRC_URI`` entry + that specifies that tarball. On the other hand, if the recipe or + append file needs to fetch a tarball and include a custom file, the + recipe or append file needs an ``SRC_URI`` variable that specifies + all those sources. + + The following list explains the available URI protocols: + + - ``file://`` : Fetches files, which are usually files shipped + with the metadata, from the local machine. The path is relative to + the :term:`FILESPATH` variable. + + - ``bzr://`` : Fetches files from a Bazaar revision control + repository. + + - ``git://`` : Fetches files from a Git revision control + repository. + + - ``osc://`` : Fetches files from an OSC (OpenSUSE Build service) + revision control repository. + + - ``repo://`` : Fetches files from a repo (Git) repository. + + - ``http://`` : Fetches files from the Internet using HTTP. + + - ``https://`` : Fetches files from the Internet using HTTPS. + + - ``ftp://`` : Fetches files from the Internet using FTP. + + - ``cvs://`` : Fetches files from a CVS revision control + repository. + + - ``hg://`` : Fetches files from a Mercurial (``hg``) revision + control repository. + + - ``p4://`` : Fetches files from a Perforce (``p4``) revision + control repository. + + - ``ssh://`` : Fetches files from a secure shell. + + - ``svn://`` : Fetches files from a Subversion (``svn``) revision + control repository. + + Here are some additional options worth mentioning: + + - ``unpack`` : Controls whether or not to unpack the file if it is + an archive. The default action is to unpack the file. + + - ``subdir`` : Places the file (or extracts its contents) into the + specified subdirectory. This option is useful for unusual tarballs + or other archives that do not have their files already in a + subdirectory within the archive. + + - ``name`` : Specifies a name to be used for association with + ``SRC_URI`` checksums when you have more than one file specified + in ``SRC_URI``. + + - ``downloadfilename`` : Specifies the filename used when storing + the downloaded file. + + SRCDATE + The date of the source code used to build the package. This variable + applies only if the source was fetched from a Source Code Manager + (SCM). + + SRCREV + The revision of the source code used to build the package. This + variable applies only when using Subversion, Git, Mercurial and + Bazaar. If you want to build a fixed revision and you want to avoid + performing a query on the remote repository every time BitBake parses + your recipe, you should specify a ``SRCREV`` that is a full revision + identifier and not just a tag. + + SRCREV_FORMAT + Helps construct valid :term:`SRCREV` values when + multiple source controlled URLs are used in + :term:`SRC_URI`. + + The system needs help constructing these values under these + circumstances. Each component in the ``SRC_URI`` is assigned a name + and these are referenced in the ``SRCREV_FORMAT`` variable. Consider + an example with URLs named "machine" and "meta". In this case, + ``SRCREV_FORMAT`` could look like "machine_meta" and those names + would have the SCM versions substituted into each position. Only one + ``AUTOINC`` placeholder is added and if needed. And, this placeholder + is placed at the start of the returned string. + + STAMP + Specifies the base path used to create recipe stamp files. The path + to an actual stamp file is constructed by evaluating this string and + then appending additional information. + + STAMPCLEAN + Specifies the base path used to create recipe stamp files. Unlike the + :term:`STAMP` variable, ``STAMPCLEAN`` can contain + wildcards to match the range of files a clean operation should + remove. BitBake uses a clean operation to remove any other stamps it + should be removing when creating a new stamp. + + SUMMARY + A short summary for the recipe, which is 72 characters or less. + + SVNDIR + The directory in which files checked out of a Subversion system are + stored. + + T + Points to a directory were BitBake places temporary files, which + consist mostly of task logs and scripts, when building a particular + recipe. + + TOPDIR + Points to the build directory. BitBake automatically sets this + variable. diff --git a/poky/bitbake/doc/bitbake-user-manual/bitbake-user-manual-ref-variables.xml b/poky/bitbake/doc/bitbake-user-manual/bitbake-user-manual-ref-variables.xml index c4bd1f258..4c29b2464 100644 --- a/poky/bitbake/doc/bitbake-user-manual/bitbake-user-manual-ref-variables.xml +++ b/poky/bitbake/doc/bitbake-user-manual/bitbake-user-manual-ref-variables.xml @@ -1124,6 +1124,67 @@ </glossdef> </glossentry> + <glossentry id='var-BBFILES_DYNAMIC'><glossterm>BBFILES_DYNAMIC</glossterm> + <info> + BBFILES_DYNAMIC[doc] = "Activates content depending on presence of identified layers." + </info> + <glossdef> + <para role="glossdeffirst"> + Activates content depending on presence of identified layers. + You identify the layers by the collections that the layers + define. + </para> + + <para> + Use the <filename>BBFILES_DYNAMIC</filename> variable to + avoid <filename>.bbappend</filename> files whose + corresponding <filename>.bb</filename> file is in a layer + that attempts to modify other layers through + <filename>.bbappend</filename> but does not want to + introduce a hard dependency on those other layers. + </para> + + <para> + Additionally you can prefix the rule with "!" to add + <filename>.bbappend</filename> and <filename>.bb</filename> files + in case a layer is not present. + Use this avoid hard dependency on those other layers. + </para> + + <para> + Use the following form for + <filename>BBFILES_DYNAMIC</filename>: + <literallayout class='monospaced'> + <replaceable>collection_name</replaceable>:<replaceable>filename_pattern</replaceable> + </literallayout> + The following example identifies two collection names and + two filename patterns: + <literallayout class='monospaced'> + BBFILES_DYNAMIC += "\ + clang-layer:${LAYERDIR}/bbappends/meta-clang/*/*/*.bbappend \ + core:${LAYERDIR}/bbappends/openembedded-core/meta/*/*/*.bbappend \ + " + </literallayout> + When the collection name is prefixed with "!" it will add the file pattern in case + the layer is absent: + <literallayout class='monospaced'> + BBFILES_DYNAMIC += "\ + !clang-layer:${LAYERDIR}/backfill/meta-clang/*/*/*.bb \ + " + </literallayout> + + This next example shows an error message that occurs + because invalid entries are found, which cause parsing to + abort: + <literallayout class='monospaced'> + ERROR: BBFILES_DYNAMIC entries must be of the form {!}<collection name>:<filename pattern>, not: + /work/my-layer/bbappends/meta-security-isafw/*/*/*.bbappend + /work/my-layer/bbappends/openembedded-core/meta/*/*/*.bbappend + </literallayout> + </para> + </glossdef> + </glossentry> + <glossentry id='var-bb-BBINCLUDED'><glossterm>BBINCLUDED</glossterm> <glossdef> <para> diff --git a/poky/bitbake/doc/conf.py b/poky/bitbake/doc/conf.py new file mode 100644 index 000000000..197f2757a --- /dev/null +++ b/poky/bitbake/doc/conf.py @@ -0,0 +1,94 @@ +# Configuration file for the Sphinx documentation builder. +# +# This file only contains a selection of the most common options. For a full +# list see the documentation: +# https://www.sphinx-doc.org/en/master/usage/configuration.html + +# -- Path setup -------------------------------------------------------------- + +# If extensions (or modules to document with autodoc) are in another directory, +# add these directories to sys.path here. If the directory is relative to the +# documentation root, use os.path.abspath to make it absolute, like shown here. +# +# import os +# import sys +# sys.path.insert(0, os.path.abspath('.')) + +import datetime + +current_version = "dev" + +# String used in sidebar +version = 'Version: ' + current_version +if current_version == 'dev': + version = 'Version: Current Development' +# Version seen in documentation_options.js and hence in js switchers code +release = current_version + +# -- Project information ----------------------------------------------------- + +project = 'Bitbake' +copyright = '2004-%s, Richard Purdie, Chris Larson, and Phil Blundell' \ + % datetime.datetime.now().year +author = 'Richard Purdie, Chris Larson, and Phil Blundell' + +# external links and substitutions +extlinks = { + 'yocto_docs': ('https://docs.yoctoproject.org%s', None), + 'oe_lists': ('https://lists.openembedded.org%s', None), +} + +# -- General configuration --------------------------------------------------- + +# Add any Sphinx extension module names here, as strings. They can be +# extensions coming with Sphinx (named 'sphinx.ext.*') or your custom +# ones. +extensions = [ + 'sphinx.ext.autosectionlabel', + 'sphinx.ext.extlinks', +] +autosectionlabel_prefix_document = True + +# Add any paths that contain templates here, relative to this directory. +templates_path = ['_templates'] + +# List of patterns, relative to source directory, that match files and +# directories to ignore when looking for source files. +# This pattern also affects html_static_path and html_extra_path. +exclude_patterns = ['_build', 'Thumbs.db', '.DS_Store'] + +# master document name. The default changed from contents to index. so better +# set it ourselves. +master_doc = 'index' + +# create substitution for project configuration variables +rst_prolog = """ +.. |project_name| replace:: %s +.. |copyright| replace:: %s +.. |author| replace:: %s +""" % (project, copyright, author) + +# -- Options for HTML output ------------------------------------------------- + +# The theme to use for HTML and HTML Help pages. See the documentation for +# a list of builtin themes. +# +html_theme = 'sphinx_rtd_theme' + +# Add any paths that contain custom static files (such as style sheets) here, +# relative to this directory. They are copied after the builtin static files, +# so a file named "default.css" will overwrite the builtin "default.css". +html_static_path = ['sphinx-static'] + +# Add customm CSS and JS files +html_css_files = ['theme_overrides.css'] +html_js_files = ['switchers.js'] + +# Hide 'Created using Sphinx' text +html_show_sphinx = False + +# Add 'Last updated' on each page +html_last_updated_fmt = '%b %d, %Y' + +# Remove the trailing 'dot' in section numbers +html_secnumber_suffix = " " diff --git a/poky/bitbake/doc/genindex.rst b/poky/bitbake/doc/genindex.rst new file mode 100644 index 000000000..a4af06f65 --- /dev/null +++ b/poky/bitbake/doc/genindex.rst @@ -0,0 +1,3 @@ +===== +Index +===== diff --git a/poky/bitbake/doc/index.rst b/poky/bitbake/doc/index.rst new file mode 100644 index 000000000..3ff8b1580 --- /dev/null +++ b/poky/bitbake/doc/index.rst @@ -0,0 +1,38 @@ +.. SPDX-License-Identifier: CC-BY-2.5 + +=================== +BitBake User Manual +=================== + +| + +.. toctree:: + :caption: Table of Contents + :numbered: + + bitbake-user-manual/bitbake-user-manual-intro + bitbake-user-manual/bitbake-user-manual-execution + bitbake-user-manual/bitbake-user-manual-metadata + bitbake-user-manual/bitbake-user-manual-fetching + bitbake-user-manual/bitbake-user-manual-ref-variables + bitbake-user-manual/bitbake-user-manual-hello + +.. toctree:: + :maxdepth: 1 + :hidden: + + genindex + releases + +---- + +.. include:: <xhtml1-lat1.txt> + +| BitBake Community +| Copyright |copy| |copyright| +| <bitbake-devel@lists.openembedded.org> + +This work is licensed under the Creative Commons Attribution License. To view a +copy of this license, visit http://creativecommons.org/licenses/by/2.5/ or send +a letter to Creative Commons, 444 Castro Street, Suite 900, Mountain View, +California 94041, USA. diff --git a/poky/bitbake/doc/releases.rst b/poky/bitbake/doc/releases.rst new file mode 100644 index 000000000..d68d71599 --- /dev/null +++ b/poky/bitbake/doc/releases.rst @@ -0,0 +1,130 @@ +.. SPDX-License-Identifier: CC-BY-2.5 + +========================= + Current Release Manuals +========================= + +**************************** +3.1 'dunfell' Release Series +**************************** + +- :yocto_docs:`3.1 BitBake User Manual </3.1/bitbake-user-manual/bitbake-user-manual.html>` +- :yocto_docs:`3.1.1 BitBake User Manual </3.1.1/bitbake-user-manual/bitbake-user-manual.html>` +- :yocto_docs:`3.1.2 BitBake User Manual </3.1.2/bitbake-user-manual/bitbake-user-manual.html>` + +========================== + Previous Release Manuals +========================== + +************************* +3.0 'zeus' Release Series +************************* + +- :yocto_docs:`3.0 BitBake User Manual </3.0/bitbake-user-manual/bitbake-user-manual.html>` +- :yocto_docs:`3.0.1 BitBake User Manual </3.0.1/bitbake-user-manual/bitbake-user-manual.html>` +- :yocto_docs:`3.0.2 BitBake User Manual </3.0.2/bitbake-user-manual/bitbake-user-manual.html>` +- :yocto_docs:`3.0.3 BitBake User Manual </3.0.3/bitbake-user-manual/bitbake-user-manual.html>` + +**************************** +2.7 'warrior' Release Series +**************************** + +- :yocto_docs:`2.7 BitBake User Manual </2.7/bitbake-user-manual/bitbake-user-manual.html>` +- :yocto_docs:`2.7.1 BitBake User Manual </2.7.1/bitbake-user-manual/bitbake-user-manual.html>` +- :yocto_docs:`2.7.2 BitBake User Manual </2.7.2/bitbake-user-manual/bitbake-user-manual.html>` +- :yocto_docs:`2.7.3 BitBake User Manual </2.7.3/bitbake-user-manual/bitbake-user-manual.html>` +- :yocto_docs:`2.7.4 BitBake User Manual </2.7.4/bitbake-user-manual/bitbake-user-manual.html>` + +************************* +2.6 'thud' Release Series +************************* + +- :yocto_docs:`2.6 BitBake User Manual </2.6/bitbake-user-manual/bitbake-user-manual.html>` +- :yocto_docs:`2.6.1 BitBake User Manual </2.6.1/bitbake-user-manual/bitbake-user-manual.html>` +- :yocto_docs:`2.6.2 BitBake User Manual </2.6.2/bitbake-user-manual/bitbake-user-manual.html>` +- :yocto_docs:`2.6.3 BitBake User Manual </2.6.3/bitbake-user-manual/bitbake-user-manual.html>` +- :yocto_docs:`2.6.4 BitBake User Manual </2.6.4/bitbake-user-manual/bitbake-user-manual.html>` + +************************* +2.5 'sumo' Release Series +************************* + +- :yocto_docs:`2.5 BitBake User Manual </2.5/bitbake-user-manual/bitbake-user-manual.html>` +- :yocto_docs:`2.5.1 BitBake User Manual </2.5.1/bitbake-user-manual/bitbake-user-manual.html>` +- :yocto_docs:`2.5.2 BitBake User Manual </2.5.2/bitbake-user-manual/bitbake-user-manual.html>` +- :yocto_docs:`2.5.3 BitBake User Manual </2.5.3/bitbake-user-manual/bitbake-user-manual.html>` + +************************** +2.4 'rocko' Release Series +************************** + +- :yocto_docs:`2.4 BitBake User Manual </2.4/bitbake-user-manual/bitbake-user-manual.html>` +- :yocto_docs:`2.4.1 BitBake User Manual </2.4.1/bitbake-user-manual/bitbake-user-manual.html>` +- :yocto_docs:`2.4.2 BitBake User Manual </2.4.2/bitbake-user-manual/bitbake-user-manual.html>` +- :yocto_docs:`2.4.3 BitBake User Manual </2.4.3/bitbake-user-manual/bitbake-user-manual.html>` +- :yocto_docs:`2.4.4 BitBake User Manual </2.4.4/bitbake-user-manual/bitbake-user-manual.html>` + +************************* +2.3 'pyro' Release Series +************************* + +- :yocto_docs:`2.3 BitBake User Manual </2.3/bitbake-user-manual/bitbake-user-manual.html>` +- :yocto_docs:`2.3.1 BitBake User Manual </2.3.1/bitbake-user-manual/bitbake-user-manual.html>` +- :yocto_docs:`2.3.2 BitBake User Manual </2.3.2/bitbake-user-manual/bitbake-user-manual.html>` +- :yocto_docs:`2.3.3 BitBake User Manual </2.3.3/bitbake-user-manual/bitbake-user-manual.html>` +- :yocto_docs:`2.3.4 BitBake User Manual </2.3.4/bitbake-user-manual/bitbake-user-manual.html>` + +************************** +2.2 'morty' Release Series +************************** + +- :yocto_docs:`2.2 BitBake User Manual </2.2/bitbake-user-manual/bitbake-user-manual.html>` +- :yocto_docs:`2.2.1 BitBake User Manual </2.2.1/bitbake-user-manual/bitbake-user-manual.html>` +- :yocto_docs:`2.2.2 BitBake User Manual </2.2.2/bitbake-user-manual/bitbake-user-manual.html>` +- :yocto_docs:`2.2.3 BitBake User Manual </2.2.3/bitbake-user-manual/bitbake-user-manual.html>` + +**************************** +2.1 'krogoth' Release Series +**************************** + +- :yocto_docs:`2.1 BitBake User Manual </2.1/bitbake-user-manual/bitbake-user-manual.html>` +- :yocto_docs:`2.1.1 BitBake User Manual </2.1.1/bitbake-user-manual/bitbake-user-manual.html>` +- :yocto_docs:`2.1.2 BitBake User Manual </2.1.2/bitbake-user-manual/bitbake-user-manual.html>` +- :yocto_docs:`2.1.3 BitBake User Manual </2.1.3/bitbake-user-manual/bitbake-user-manual.html>` + +*************************** +2.0 'jethro' Release Series +*************************** + +- :yocto_docs:`1.9 BitBake User Manual </1.9/bitbake-user-manual/bitbake-user-manual.html>` +- :yocto_docs:`2.0 BitBake User Manual </2.0/bitbake-user-manual/bitbake-user-manual.html>` +- :yocto_docs:`2.0.1 BitBake User Manual </2.0.1/bitbake-user-manual/bitbake-user-manual.html>` +- :yocto_docs:`2.0.2 BitBake User Manual </2.0.2/bitbake-user-manual/bitbake-user-manual.html>` +- :yocto_docs:`2.0.3 BitBake User Manual </2.0.3/bitbake-user-manual/bitbake-user-manual.html>` + +************************* +1.8 'fido' Release Series +************************* + +- :yocto_docs:`1.8 BitBake User Manual </1.8/bitbake-user-manual/bitbake-user-manual.html>` +- :yocto_docs:`1.8.1 BitBake User Manual </1.8.1/bitbake-user-manual/bitbake-user-manual.html>` +- :yocto_docs:`1.8.2 BitBake User Manual </1.8.2/bitbake-user-manual/bitbake-user-manual.html>` + +************************** +1.7 'dizzy' Release Series +************************** + +- :yocto_docs:`1.7 BitBake User Manual </1.7/bitbake-user-manual/bitbake-user-manual.html>` +- :yocto_docs:`1.7.1 BitBake User Manual </1.7.1/bitbake-user-manual/bitbake-user-manual.html>` +- :yocto_docs:`1.7.2 BitBake User Manual </1.7.2/bitbake-user-manual/bitbake-user-manual.html>` +- :yocto_docs:`1.7.3 BitBake User Manual </1.7.3/bitbake-user-manual/bitbake-user-manual.html>` + +************************** +1.6 'daisy' Release Series +************************** + +- :yocto_docs:`1.6 BitBake User Manual </1.6/bitbake-user-manual/bitbake-user-manual.html>` +- :yocto_docs:`1.6.1 BitBake User Manual </1.6.1/bitbake-user-manual/bitbake-user-manual.html>` +- :yocto_docs:`1.6.2 BitBake User Manual </1.6.2/bitbake-user-manual/bitbake-user-manual.html>` +- :yocto_docs:`1.6.3 BitBake User Manual </1.6.3/bitbake-user-manual/bitbake-user-manual.html>` + diff --git a/poky/bitbake/doc/sphinx-static/switchers.js b/poky/bitbake/doc/sphinx-static/switchers.js new file mode 100644 index 000000000..32113cfa9 --- /dev/null +++ b/poky/bitbake/doc/sphinx-static/switchers.js @@ -0,0 +1,233 @@ +(function() { + 'use strict'; + + var all_versions = { + 'dev': 'dev (3.2)', + '3.1.2': '3.1.2', + '3.0.3': '3.0.3', + '2.7.4': '2.7.4', + }; + + var all_doctypes = { + 'single': 'Individual Webpages', + 'mega': "All-in-one 'Mega' Manual", + }; + + // Simple version comparision + // Return 1 if a > b + // Return -1 if a < b + // Return 0 if a == b + function ver_compare(a, b) { + if (a == "dev") { + return 1; + } + + if (a === b) { + return 0; + } + + var a_components = a.split("."); + var b_components = b.split("."); + + var len = Math.min(a_components.length, b_components.length); + + // loop while the components are equal + for (var i = 0; i < len; i++) { + // A bigger than B + if (parseInt(a_components[i]) > parseInt(b_components[i])) { + return 1; + } + + // B bigger than A + if (parseInt(a_components[i]) < parseInt(b_components[i])) { + return -1; + } + } + + // If one's a prefix of the other, the longer one is greater. + if (a_components.length > b_components.length) { + return 1; + } + + if (a_components.length < b_components.length) { + return -1; + } + + // Otherwise they are the same. + return 0; + } + + function build_version_select(current_series, current_version) { + var buf = ['<select>']; + + $.each(all_versions, function(version, title) { + var series = version.substr(0, 3); + if (series == current_series) { + if (version == current_version) + buf.push('<option value="' + version + '" selected="selected">' + title + '</option>'); + else + buf.push('<option value="' + version + '">' + title + '</option>'); + + if (version != current_version) + buf.push('<option value="' + current_version + '" selected="selected">' + current_version + '</option>'); + } else { + buf.push('<option value="' + version + '">' + title + '</option>'); + } + }); + + buf.push('</select>'); + return buf.join(''); + } + + function build_doctype_select(current_doctype) { + var buf = ['<select>']; + + $.each(all_doctypes, function(doctype, title) { + if (doctype == current_doctype) + buf.push('<option value="' + doctype + '" selected="selected">' + + all_doctypes[current_doctype] + '</option>'); + else + buf.push('<option value="' + doctype + '">' + title + '</option>'); + }); + if (!(current_doctype in all_doctypes)) { + // In case we're browsing a doctype that is not yet in all_doctypes. + buf.push('<option value="' + current_doctype + '" selected="selected">' + + current_doctype + '</option>'); + all_doctypes[current_doctype] = current_doctype; + } + buf.push('</select>'); + return buf.join(''); + } + + function navigate_to_first_existing(urls) { + // Navigate to the first existing URL in urls. + var url = urls.shift(); + + // Web browsers won't redirect file:// urls to file urls using ajax but + // its useful for local testing + if (url.startsWith("file://")) { + window.location.href = url; + return; + } + + if (urls.length == 0) { + window.location.href = url; + return; + } + $.ajax({ + url: url, + success: function() { + window.location.href = url; + }, + error: function() { + navigate_to_first_existing(urls); + } + }); + } + + function get_docroot_url() { + var url = window.location.href; + var root = DOCUMENTATION_OPTIONS.URL_ROOT; + + var urlarray = url.split('/'); + // Trim off anything after '/' + urlarray.pop(); + var depth = (root.match(/\.\.\//g) || []).length; + for (var i = 0; i < depth; i++) { + urlarray.pop(); + } + + return urlarray.join('/') + '/'; + } + + function on_version_switch() { + var selected_version = $(this).children('option:selected').attr('value'); + var url = window.location.href; + var current_version = DOCUMENTATION_OPTIONS.VERSION; + var docroot = get_docroot_url() + + var new_versionpath = selected_version + '/'; + if (selected_version == "dev") + new_versionpath = ''; + + // dev versions have no version prefix + if (current_version == "dev") { + var new_url = docroot + new_versionpath + url.replace(docroot, ""); + var fallback_url = docroot + new_versionpath; + } else { + var new_url = url.replace('/' + current_version + '/', '/' + new_versionpath); + var fallback_url = new_url.replace(url.replace(docroot, ""), ""); + } + + console.log(get_docroot_url()) + console.log(url + " to url " + new_url); + console.log(url + " to fallback " + fallback_url); + + if (new_url != url) { + navigate_to_first_existing([ + new_url, + fallback_url, + 'https://www.yoctoproject.org/docs/', + ]); + } + } + + function on_doctype_switch() { + var selected_doctype = $(this).children('option:selected').attr('value'); + var url = window.location.href; + if (selected_doctype == 'mega') { + var docroot = get_docroot_url() + var current_version = DOCUMENTATION_OPTIONS.VERSION; + // Assume manuals before 3.2 are using old docbook mega-manual + if (ver_compare(current_version, "3.2") < 0) { + var new_url = docroot + "mega-manual/mega-manual.html"; + } else { + var new_url = docroot + "singleindex.html"; + } + } else { + var new_url = url.replace("singleindex.html", "index.html") + } + + if (new_url != url) { + navigate_to_first_existing([ + new_url, + 'https://www.yoctoproject.org/docs/', + ]); + } + } + + // Returns the current doctype based upon the url + function doctype_segment_from_url(url) { + if (url.includes("singleindex") || url.includes("mega-manual")) + return "mega"; + return "single"; + } + + $(document).ready(function() { + var release = DOCUMENTATION_OPTIONS.VERSION; + var current_doctype = doctype_segment_from_url(window.location.href); + var current_series = release.substr(0, 3); + var version_select = build_version_select(current_series, release); + + $('.version_switcher_placeholder').html(version_select); + $('.version_switcher_placeholder select').bind('change', on_version_switch); + + var doctype_select = build_doctype_select(current_doctype); + + $('.doctype_switcher_placeholder').html(doctype_select); + $('.doctype_switcher_placeholder select').bind('change', on_doctype_switch); + + if (ver_compare(release, "3.1") < 0) { + $('#outdated-warning').html('Version ' + release + ' of the project is now considered obsolete, please select and use a more recent version'); + $('#outdated-warning').css('padding', '.5em'); + } else if (release != "dev") { + $.each(all_versions, function(version, title) { + var series = version.substr(0, 3); + if (series == current_series && version != release) { + $('#outdated-warning').html('This document is for outdated version ' + release + ', you should select the latest release version in this series, ' + version + '.'); + $('#outdated-warning').css('padding', '.5em'); + } + }); + } + }); +})(); diff --git a/poky/bitbake/doc/sphinx-static/theme_overrides.css b/poky/bitbake/doc/sphinx-static/theme_overrides.css new file mode 100644 index 000000000..4fd76a152 --- /dev/null +++ b/poky/bitbake/doc/sphinx-static/theme_overrides.css @@ -0,0 +1,164 @@ +/* + SPDX-License-Identifier: CC-BY-2.0-UK +*/ + +body { + font-family: Verdana, Sans, sans-serif; + + min-width: 640px; + margin: 0em auto; + color: #333; +} + +h1,h2,h3,h4,h5,h6,h7 { + font-family: Arial, Sans; + color: #00557D; + clear: both; +} + +h1 { + font-size: 2em; + text-align: left; + padding: 0em 0em 0em 0em; + margin: 2em 0em 0em 0em; +} + +h2.subtitle { + margin: 0.10em 0em 3.0em 0em; + padding: 0em 0em 0em 0em; + font-size: 1.8em; + padding-left: 20%; + font-weight: normal; + font-style: italic; +} + +h2 { + margin: 2em 0em 0.66em 0em; + padding: 0.5em 0em 0em 0em; + font-size: 1.5em; + font-weight: bold; +} + +h3.subtitle { + margin: 0em 0em 1em 0em; + padding: 0em 0em 0em 0em; + font-size: 142.14%; + text-align: right; +} + +h3 { + margin: 1em 0em 0.5em 0em; + padding: 1em 0em 0em 0em; + font-size: 140%; + font-weight: bold; +} + +h4 { + margin: 1em 0em 0.5em 0em; + padding: 1em 0em 0em 0em; + font-size: 120%; + font-weight: bold; +} + +h5 { + margin: 1em 0em 0.5em 0em; + padding: 1em 0em 0em 0em; + font-size: 110%; + font-weight: bold; +} + +h6 { + margin: 1em 0em 0em 0em; + padding: 1em 0em 0em 0em; + font-size: 110%; + font-weight: bold; +} + +em { + font-weight: bold; +} + +.pre { + font-size: medium; + font-family: Courier, monospace; +} + +.wy-nav-content a { + text-decoration: underline; + color: #444; + background: transparent; +} + +.wy-nav-content a:hover { + text-decoration: underline; + background-color: #dedede; +} + +.wy-nav-content a:visited { + color: #444; +} + +[alt='Permalink'] { color: #eee; } +[alt='Permalink']:hover { color: black; } + +@media screen { + /* content column + * + * RTD theme's default is 800px as max width for the content, but we have + * tables with tons of columns, which need the full width of the view-port. + */ + + .wy-nav-content{max-width: none; } + + /* inline literal: drop the borderbox, padding and red color */ + code, .rst-content tt, .rst-content code { + color: inherit; + border: none; + padding: unset; + background: inherit; + font-size: 85%; + } + + .rst-content tt.literal,.rst-content tt.literal,.rst-content code.literal { + color: inherit; + } + + /* Admonition should be gray, not blue or green */ + .rst-content .note .admonition-title, + .rst-content .tip .admonition-title, + .rst-content .warning .admonition-title, + .rst-content .caution .admonition-title, + .rst-content .important .admonition-title { + background: #f0f0f2; + color: #00557D; + + } + + .rst-content .note, + .rst-content .tip, + .rst-content .important, + .rst-content .warning, + .rst-content .caution { + background: #f0f0f2; + } + + /* Remove the icon in front of note/tip element, and before the logo */ + .icon-home:before, .rst-content .admonition-title:before { + display: none + } + + /* a custom informalexample container is used in some doc */ + .informalexample { + border: 1px solid; + border-color: #aaa; + margin: 1em 0em; + padding: 1em; + page-break-inside: avoid; + } + + /* Remove the blue background in the top left corner, around the logo */ + .wy-side-nav-search { + background: inherit; + } + +} |