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Diffstat (limited to 'poky/documentation/bsp-guide/bsp.rst')
| -rw-r--r-- | poky/documentation/bsp-guide/bsp.rst | 100 |
1 files changed, 42 insertions, 58 deletions
diff --git a/poky/documentation/bsp-guide/bsp.rst b/poky/documentation/bsp-guide/bsp.rst index 024a240c2..408620212 100644 --- a/poky/documentation/bsp-guide/bsp.rst +++ b/poky/documentation/bsp-guide/bsp.rst @@ -1,4 +1,4 @@ -.. SPDX-License-Identifier: CC-BY-2.0-UK +.. SPDX-License-Identifier: CC-BY-SA-2.0-UK ************************************************ Board Support Packages (BSP) - Developer's Guide @@ -31,14 +31,14 @@ convention: :: meta-bsp_root_name The string "meta-" is prepended to the -machine or platform name, which is bsp_root_name in the above form. +machine or platform name, which is "bsp_root_name" in the above form. .. note:: Because the BSP layer naming convention is well-established, it is advisable to follow it when creating layers. Technically speaking, a - BSP layer name does not need to start with - meta-. However, various scripts and tools in the Yocto Project development + BSP layer name does not need to start with ``meta-``. + However, various scripts and tools in the Yocto Project development environment assume this convention. To help understand the BSP layer concept, consider the BSPs that the @@ -81,7 +81,7 @@ directory of that Layer. This directory is what you add to the ``conf/bblayers.conf`` file found in your :term:`Build Directory`, which is established after you run the OpenEmbedded build environment setup -script (i.e. :ref:`ref-manual/ref-structure:\`\`oe-init-build-env\`\`` ). +script (i.e. :ref:`ref-manual/ref-structure:\`\`oe-init-build-env\`\``). Adding the root directory allows the :term:`OpenEmbedded Build System` to recognize the BSP layer and from it build an image. Here is an example: :: @@ -95,10 +95,11 @@ layer and from it build an image. Here is an example: :: .. note:: - Ordering and ``BBFILE_PRIORITY`` for the layers listed in BBLAYERS matter. For - example, if multiple layers define a machine configuration, the OpenEmbedded - build system uses the last layer searched given similar layer priorities. The - build system works from the top-down through the layers listed in ``BBLAYERS``. + Ordering and :term:`BBFILE_PRIORITY` for the layers listed in ``BBLAYERS`` + matter. For example, if multiple layers define a machine configuration, the + OpenEmbedded build system uses the last layer searched given similar layer + priorities. The build system works from the top-down through the layers + listed in ``BBLAYERS``. Some BSPs require or depend on additional layers beyond the BSP's root layer in order to be functional. In this case, you need to specify these @@ -107,7 +108,7 @@ Additionally, if any build instructions exist for the BSP, you must add them to the "Dependencies" section. Some layers function as a layer to hold other BSP layers. These layers -are knows as ":term:`container layers <Container Layer>`". An example of +are known as ":term:`container layers <Container Layer>`". An example of this type of layer is OpenEmbedded's `meta-openembedded <https://github.com/openembedded/meta-openembedded>`__ layer. The ``meta-openembedded`` layer contains many ``meta-*`` layers. @@ -141,8 +142,8 @@ section. .. note:: - For structural information on BSPs, see the Example Filesystem Layout - section. + For structural information on BSPs, see the + :ref:`bsp-guide/bsp:example filesystem layout` section. #. *Set Up the Build Environment:* Be sure you are set up to use BitBake in a shell. See the ":ref:`dev-manual/dev-manual-start:preparing the build host`" @@ -150,10 +151,10 @@ section. to get a build host ready that is either a native Linux machine or a machine that uses CROPS. -#. *Clone the ``poky`` Repository:* You need to have a local copy of the +#. *Clone the poky Repository:* You need to have a local copy of the Yocto Project :term:`Source Directory` (i.e. a local ``poky`` repository). See the - "ref:`dev-manual/dev-manual-start:cloning the ``poky`` repository`" and + ":ref:`dev-manual/dev-manual-start:cloning the \`\`poky\`\` repository`" and possibly the ":ref:`dev-manual/dev-manual-start:checking out by branch in poky`" or ":ref:`dev-manual/dev-manual-start:checking out by tag in poky`" @@ -168,7 +169,7 @@ section. BSP layers, you can look at the `index of machines <&YOCTO_RELEASE_DL_URL;/machines>`__ for the release. -#. *Optionally Clone the ``meta-intel`` BSP Layer:* If your hardware is +#. *Optionally Clone the meta-intel BSP Layer:* If your hardware is based on current Intel CPUs and devices, you can leverage this BSP layer. For details on the ``meta-intel`` BSP layer, see the layer's `README <http://git.yoctoproject.org/cgit/cgit.cgi/meta-intel/tree/README>`__ @@ -193,7 +194,7 @@ section. #. *Check Out the Proper Branch:* The branch you check out for ``meta-intel`` must match the same branch you are using for the - Yocto Project release (e.g. &DISTRO_NAME_NO_CAP;): :: + Yocto Project release (e.g. ``&DISTRO_NAME_NO_CAP;``): :: $ cd meta-intel $ git checkout -b &DISTRO_NAME_NO_CAP; remotes/origin/&DISTRO_NAME_NO_CAP; @@ -233,15 +234,13 @@ section. setup script to define the OpenEmbedded build environment on your build host. :: - $ source &OE_INIT_FILE; + $ source oe-init-build-env Among other things, the script creates the :term:`Build Directory`, which is ``build`` in this case and is located in the :term:`Source Directory`. After the script runs, your current working directory is set to the ``build`` directory. -.. _bsp-filelayout: - Example Filesystem Layout ========================= @@ -291,7 +290,9 @@ individual BSPs could differ. :: meta-bsp_root_name/recipes-kernel/linux/linux-yocto_kernel_rev.bbappend Below is an example of the Raspberry Pi BSP layer that is available from -the :yocto_git:`Source Respositories <>`: :: +the :yocto_git:`Source Respositories <>`: + +.. code-block:: none meta-raspberrypi/COPYING.MIT meta-raspberrypi/README.md @@ -448,8 +449,6 @@ the :yocto_git:`Source Respositories <>`: :: The following sections describe each part of the proposed BSP format. -.. _bsp-filelayout-license: - License Files ------------- @@ -468,8 +467,6 @@ developer. For information on how to maintain license compliance, see the ":ref:`dev-manual/dev-manual-common-tasks:maintaining open source license compliance during your product's lifecycle`" section in the Yocto Project Development Tasks Manual. -.. _bsp-filelayout-readme: - README File ----------- @@ -485,8 +482,6 @@ At a minimum, the ``README`` file must contain a list of dependencies, such as the names of any other layers on which the BSP depends and the name of the BSP maintainer with his or her contact information. -.. _bsp-filelayout-readme-sources: - README.sources File ------------------- @@ -506,8 +501,6 @@ used to generate the images that ship with the BSP. If the BSP's ``binary`` directory is missing or the directory has no images, an existing ``README.sources`` file is meaningless and usually does not exist. -.. _bsp-filelayout-binary: - Pre-built User Binaries ----------------------- @@ -531,8 +524,6 @@ hardware. Additionally, the present to locate the sources used to build the images and provide information on the Metadata. -.. _bsp-filelayout-layer: - Layer Configuration File ------------------------ @@ -544,13 +535,13 @@ The ``conf/layer.conf`` file identifies the file structure as a layer, identifies the contents of the layer, and contains information about how the build system should use it. Generally, a standard boilerplate file such as the following works. In the following example, you would replace -bsp with the actual name of the BSP (i.e. bsp_root_name from the example +"bsp" with the actual name of the BSP (i.e. "bsp_root_name" from the example template). :: # We have a conf and classes directory, add to BBPATH BBPATH .= ":${LAYERDIR}" - # We have a recipes directory, add to BBFILES + # We have a recipes directory containing .bb and .bbappend files, add to BBFILES BBFILES += "${LAYERDIR}/recipes-*/*/*.bb \ ${LAYERDIR}/recipes-*/*/*.bbappend" @@ -583,8 +574,6 @@ This file simply makes :term:`BitBake` aware of the recipes and configuration directories. The file must exist so that the OpenEmbedded build system can recognize the BSP. -.. _bsp-filelayout-machine: - Hardware Configuration Options ------------------------------ @@ -623,8 +612,6 @@ configuration file. For example, the Raspberry Pi BSP include conf/machine/include/rpi-base.inc -.. _bsp-filelayout-misc-recipes: - Miscellaneous BSP-Specific Recipe Files --------------------------------------- @@ -655,8 +642,6 @@ directory. Here is the ``machconfig`` file for the Raspberry Pi BSP: :: ``meta/recipes-bsp/formfactor/formfactor_0.0.bb``, which is found in the :term:`Source Directory`. -.. _bsp-filelayout-recipes-graphics: - Display Support Files --------------------- @@ -668,8 +653,6 @@ This optional directory contains recipes for the BSP if it has special requirements for graphics support. All files that are needed for the BSP to support a display are kept here. -.. _bsp-filelayout-kernel: - Linux Kernel Configuration -------------------------- @@ -694,7 +677,7 @@ located in the BSP Layer for your target device (e.g. the Suppose you are using the ``linux-yocto_4.4.bb`` recipe to build the kernel. In other words, you have selected the kernel in your -bsp_root_name\ ``.conf`` file by adding +``"bsp_root_name".conf`` file by adding :term:`PREFERRED_PROVIDER` and :term:`PREFERRED_VERSION` statements as follows: :: @@ -704,7 +687,7 @@ statements as follows: :: .. note:: When the preferred provider is assumed by default, the ``PREFERRED_PROVIDER`` - statement does not appear in the ``bsp_root_name`` .conf file. + statement does not appear in the ``"bsp_root_name".conf`` file. You would use the ``linux-yocto_4.4.bbappend`` file to append specific BSP settings to the kernel, thus configuring the kernel for your @@ -781,7 +764,7 @@ workflow. .. note:: - - Five hardware reference BSPs exist that are part of the Yocto + - Four hardware reference BSPs exist that are part of the Yocto Project release and are located in the ``poky/meta-yocto-bsp`` BSP layer: @@ -870,8 +853,8 @@ Before looking at BSP requirements, you should consider the following: - The requirements in this section apply regardless of how you package a BSP. You should consult the packaging and distribution guidelines for your specific release process. For an example of packaging and - distribution requirements, see the "`Third Party BSP Release - Process <https://wiki.yoctoproject.org/wiki/Third_Party_BSP_Release_Process>`__" + distribution requirements, see the ":yocto_wiki:`Third Party BSP Release + Process </wiki/Third_Party_BSP_Release_Process>`" wiki page. - The requirements for the BSP as it is made available to a developer @@ -897,7 +880,7 @@ Yocto Project: your BSP layer as listed in the ``recipes.txt`` file, which is found in ``poky/meta`` directory of the :term:`Source Directory` or in the OpenEmbedded-Core Layer (``openembedded-core``) at - http://git.openembedded.org/openembedded-core/tree/meta. + https://git.openembedded.org/openembedded-core/tree/meta. You should place recipes (``*.bb`` files) and recipe modifications (``*.bbappend`` files) into ``recipes-*`` subdirectories by @@ -1074,7 +1057,7 @@ also supports several other machines: .. note:: - If the meta-xyz layer did not support multiple machines, you would place + If the ``meta-xyz`` layer did not support multiple machines, you would place the interfaces configuration file in the layer here: :: meta-xyz/recipes-core/init-ifupdown/files/interfaces @@ -1233,7 +1216,7 @@ file. In this example, the ``conf/layer.conf`` is the following: :: # We have a conf and classes directory, add to BBPATH BBPATH .= ":${LAYERDIR}" - # We have recipes-\* directories, add to BBFILES + # We have a recipes directory containing .bb and .bbappend files, add to BBFILES BBFILES += "${LAYERDIR}/recipes-*/*/*.bb \ ${LAYERDIR}/recipes-*/*/*.bbappend" @@ -1262,13 +1245,13 @@ general or kernel layer. One or more machine configuration files exist in the ``bsp_layer/conf/machine/`` directory of the layer: :: - bsp_layer/conf/machine/machine1\.conf`` - bsp_layer/conf/machine/machine2\.conf`` - bsp_layer/conf/machine/machine3\.conf`` + bsp_layer/conf/machine/machine1\.conf + bsp_layer/conf/machine/machine2\.conf + bsp_layer/conf/machine/machine3\.conf ... more ... For example, the machine configuration file for the `BeagleBone and -BeagleBone Black development boards <http://beagleboard.org/bone>`__ is +BeagleBone Black development boards <https://beagleboard.org/bone>`__ is located in the layer ``poky/meta-yocto-bsp/conf/machine`` and is named ``beaglebone-yocto.conf``: :: @@ -1344,7 +1327,7 @@ Project Reference Manual. .. tip:: - Many ``MACHINE\*`` variables exist that help you configure a particular piece + Many ``MACHINE*`` variables exist that help you configure a particular piece of hardware. - :term:`EXTRA_IMAGEDEPENDS`: @@ -1359,12 +1342,12 @@ Project Reference Manual. These features, which are collectively known as "tuning features", exist in the :term:`OpenEmbedded-Core (OE-Core)` layer (e.g. ``poky/meta/conf/machine/include``). In this example, the default - tunning file is "cortexa8hf-neon". + tuning file is "cortexa8hf-neon". .. note:: The include statement that pulls in the - conf/machine/include/tune-cortexa8.inc file provides many tuning + ``conf/machine/include/tune-cortexa8.inc`` file provides many tuning possibilities. - :term:`IMAGE_FSTYPES`: The @@ -1389,7 +1372,7 @@ Project Reference Manual. - ``do_image_wic[depends]``: A task that is constructed during the build. In this example, the task depends on specific tools in order - to create the sysroot when buiding a Wic image. + to create the sysroot when building a Wic image. - :term:`SERIAL_CONSOLES`: Defines a serial console (TTY) to enable using getty. In this case, @@ -1429,7 +1412,8 @@ Project Reference Manual. .. note:: - For more information on how the SPL variables are used, see the u-boot.inc + For more information on how the SPL variables are used, see the + :yocto_git:`u-boot.inc </cgit/cgit.cgi/poky/tree/meta/recipes-bsp/u-boot/u-boot.inc>` include file. - :term:`UBOOT_* <UBOOT_ENTRYPOINT>`: Defines @@ -1473,7 +1457,7 @@ The ``meta-yocto-bsp/recipes-kernel/linux`` directory in the layer contains metadata used to build the kernel. In this case, a kernel append file (i.e. ``linux-yocto_5.0.bbappend``) is used to override an established kernel recipe (i.e. ``linux-yocto_5.0.bb``), which is located in -https://git.yoctoproject.org/cgit/cgit.cgi/poky/tree/meta/recipes-kernel/linux. +:yocto_git:`/cgit/cgit.cgi/poky/tree/meta/recipes-kernel/linux`. Following is the contents of the append file: :: |