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Diffstat (limited to 'poky/bitbake/doc/bitbake-user-manual/bitbake-user-manual-metadata.rst')
| -rw-r--r-- | poky/bitbake/doc/bitbake-user-manual/bitbake-user-manual-metadata.rst | 171 |
1 files changed, 86 insertions, 85 deletions
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 index 20c330e6a..b0494d080 100644 --- a/poky/bitbake/doc/bitbake-user-manual/bitbake-user-manual-metadata.rst +++ b/poky/bitbake/doc/bitbake-user-manual/bitbake-user-manual-metadata.rst @@ -91,9 +91,10 @@ level changes: Variables that are exported to the environment are preceded by the string "export" in the command's output. -- For recipe changes, use the following:: +- To find changes to a given variable in a specific recipe, use the + following:: - $ bitbake recipe -e \| grep VARIABLE=" + $ bitbake recipename -e | grep VARIABLENAME=\" This command checks to see if the variable actually makes it into a specific recipe. @@ -225,7 +226,7 @@ immediately, rather than when the variable is actually used:: 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 +of :term:`T` is "456". The variable :term:`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`` @@ -248,7 +249,7 @@ examples:: C = "cval" C =+ "test" -The variable ``B`` contains "bval additionaldata" and ``C`` contains "test +The variable :term:`B` contains "bval additionaldata" and ``C`` contains "test cval". .. _appending-and-prepending-without-spaces: @@ -267,7 +268,7 @@ examples:: C = "cval" C =. "test" -The variable ``B`` contains "bvaladditionaldata" and ``C`` contains +The variable :term:`B` contains "bvaladditionaldata" and ``C`` contains "testcval". Appending and Prepending (Override Style Syntax) @@ -281,13 +282,13 @@ 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" + B:append = " additional data" C = "cval" - C_prepend = "additional data " + C:prepend = "additional data " D = "dval" - D_append = "additional data" + D:append = "additional data" -The variable ``B`` +The variable :term:`B` becomes "bval additional data" and ``C`` becomes "additional data cval". The variable ``D`` becomes "dvaladditional data". @@ -312,10 +313,10 @@ 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" + FOO:remove = "123" + FOO:remove = "456" FOO2 = " abc def ghi abcdef abc def abc def def" - FOO2_remove = "\ + FOO2:remove = "\ def \ abc \ ghi \ @@ -324,14 +325,14 @@ Surrounding spaces and spacing are preserved. Here is an example:: The variable ``FOO`` becomes " 789 123456 " and ``FOO2`` becomes " abcdef ". -Like "_append" and "_prepend", "_remove" is applied at variable +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 +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:: @@ -346,18 +347,18 @@ 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 +uses the ":append" operator, then the final value of ``FOO`` will be "initial val", as intended:: - FOO_append = " val" + FOO:append = " val" .. note:: - It is never necessary to use "+=" together with "_append". The following + It is never necessary to use "+=" together with ":append". The following sequence of assignments appends "barbaz" to FOO:: - FOO_append = "bar" - FOO_append = "baz" + FOO:append = "bar" + FOO:append = "baz" The only effect of changing the second assignment in the previous @@ -378,8 +379,8 @@ You can find more out about variable flags in general in the 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"). +except for override style syntax (i.e. ":prepend", ":append", and +":remove"). Here are some examples showing how to set variable flags:: @@ -496,14 +497,14 @@ 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 +files. This section describes how you can use :term:`OVERRIDES` as conditional metadata, talks about key expansion in relationship to -``OVERRIDES``, and provides some examples to help with understanding. +:term:`OVERRIDES`, and provides some examples to help with understanding. Conditional Metadata -------------------- -You can use ``OVERRIDES`` to conditionally select a specific version of +You can use :term:`OVERRIDES` to conditionally select a specific version of a variable and to conditionally append or prepend the value of a variable. @@ -513,10 +514,10 @@ variable. 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 +- *Selecting a Variable:* The :term:`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 + conditional on "arm", and "arm" is in :term:`OVERRIDES`, then the "arm"-specific version of the variable is used rather than the non-conditional version. Here is an example:: @@ -525,7 +526,7 @@ variable. TEST_os = "osspecific" TEST_nooverride = "othercondvalue" - In this example, the ``OVERRIDES`` + In this example, the :term:`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 @@ -538,36 +539,36 @@ variable. 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" + 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:: + listed in :term:`OVERRIDES`. Here is an example:: DEPENDS = "glibc ncurses" OVERRIDES = "machine:local" - DEPENDS_append_machine = "libmad" + DEPENDS:append:machine = "libmad" - In this example, ``DEPENDS`` becomes "glibc ncurses libmad". + In this example, :term:`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" + KERNEL_FEATURES:append = " ${KERNEL_EXTRA_FEATURES}" + KERNEL_FEATURES:append:qemux86=" cfg/sound.scc cfg/paravirt_kvm.scc" + KERNEL_FEATURES:append:qemux86-64=" cfg/sound.scc cfg/paravirt_kvm.scc" - *Setting a Variable for a Single Task:* BitBake supports setting a variable just for the duration of a single task. Here is an example:: FOO_task-configure = "val 1" - FOO_task-compile = "val 2" + FOO:task-compile = "val 2" In the previous example, ``FOO`` has the value "val 1" while the @@ -580,9 +581,9 @@ variable. ``do_compile`` task. You can also use this syntax with other combinations (e.g. - "``_prepend``") as shown in the following example:: + "``:prepend``") as shown in the following example:: - EXTRA_OEMAKE_prepend_task-compile = "${PARALLEL_MAKE} " + EXTRA_OEMAKE:prepend:task-compile = "${PARALLEL_MAKE} " Key Expansion ------------- @@ -612,33 +613,33 @@ 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 +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" + 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 +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 +:term:`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" + A:append:foo = "X" For this case, before -overrides are handled, ``A`` is set to "Z" and ``A_append_foo`` is set +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. @@ -648,21 +649,21 @@ back as in the first example:: OVERRIDES = "foo" A = "Y" - A_foo_append = "Z" - A_foo_append = "X" + 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" +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``). +``A`` is replaced with ``A:foo``). This final example mixes in some varying operators:: A = "1" - A_append = "2" - A_append = "3" + A:append = "2" + A:append = "3" A += "4" A .= "5" @@ -670,7 +671,7 @@ 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. +these assignments are made, BitBake applies the ":append" operations. Those operations result in ``A`` becoming "1 4523". Sharing Functionality @@ -686,7 +687,7 @@ 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`` +include ``include``, ``inherit``, :term:`INHERIT`, and ``require`` directives. Locating Include and Class Files @@ -702,7 +703,7 @@ current directory for ``include`` and ``require`` directives. 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``. +:term:`BBPATH`. ``inherit`` Directive --------------------- @@ -725,7 +726,7 @@ 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``. +``classes/autotools.bbclass`` in :term:`BBPATH`. .. note:: @@ -752,7 +753,7 @@ parsed. One way to achieve a conditional inherit in this case is to use overrides:: VARIABLE = "" - VARIABLE_someoverride = "myclass" + VARIABLE:someoverride = "myclass" Another method is by using anonymous Python. Here is an example:: @@ -780,7 +781,7 @@ 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``. +BitBake locates the first file it can find within :term:`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>` @@ -822,7 +823,7 @@ 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``. +locates the first file it can find within :term:`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 @@ -851,7 +852,7 @@ As an example, suppose you needed to inherit a class file called 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``. +subdirectory in one of the directories specified in :term:`BBPATH`. .. note:: @@ -907,7 +908,7 @@ 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`` +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. @@ -919,7 +920,7 @@ As an example, consider the following:: fn } - fn_prepend() { + fn:prepend() { bbplain second } @@ -927,7 +928,7 @@ As an example, consider the following:: bbplain third } - do_foo_append() { + do_foo:append() { bbplain fourth } @@ -977,7 +978,7 @@ override-style operators to BitBake-style Python functions. As an example, consider the following:: - python do_foo_prepend() { + python do_foo:prepend() { bb.plain("first") } @@ -985,7 +986,7 @@ As an example, consider the following:: bb.plain("second") } - python do_foo_append() { + python do_foo:append() { bb.plain("third") } @@ -1015,7 +1016,7 @@ is an example:: SOMECONDITION = "1" DEPENDS = "${@get_depends(d)}" -This would result in ``DEPENDS`` containing ``dependencywithcond``. +This would result in :term:`DEPENDS` containing ``dependencywithcond``. Here are some things to know about Python functions: @@ -1134,12 +1135,12 @@ equivalent to the following snippet:: 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 +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" + FOO:append = " from outside" python () { d.setVar("FOO", "foo from anonymous") @@ -1164,7 +1165,7 @@ 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 +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 @@ -1382,7 +1383,7 @@ 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 +The :term:`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:: @@ -1467,7 +1468,7 @@ functionality of the task: 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 + the :term:`BB_NUMBER_THREADS` variable causes ``number_threads`` to have no effect. - ``[postfuncs]``: List of functions to call after the completion of @@ -1537,7 +1538,7 @@ 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:: +and the content of the :term:`FILE` variable:: addhandler myclass_eventhandler python myclass_eventhandler() { @@ -1576,7 +1577,7 @@ 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 + :term:`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 @@ -1733,13 +1734,13 @@ 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 +the task of each item listed in :term:`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 +of each item in :term:`DEPENDS` must complete before ``do_configure`` can execute. Runtime Dependencies @@ -1748,8 +1749,8 @@ 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 +The :term:`PACKAGES` variable lists runtime packages. Each of those packages +can have :term:`RDEPENDS` and :term:`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. :: @@ -1757,9 +1758,9 @@ executed. :: do_package_qa[rdeptask] = "do_packagedata" In the previous -example, the ``do_packagedata`` task of each item in ``RDEPENDS`` must +example, the ``do_packagedata`` task of each item in :term:`RDEPENDS` must have completed before ``do_package_qa`` can execute. -Although ``RDEPENDS`` contains entries from the +Although :term:`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. @@ -1802,7 +1803,7 @@ 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:: +data in :term:`DEPENDS`. Here is an example:: do_patch[depends] = "quilt-native:do_populate_sysroot" |