1.. SPDX-License-Identifier: CC-BY-SA-2.0-UK
2
3=========================
4Yocto Project Quick Build
5=========================
6
7Welcome!
8========
9
10This short document steps you through the process for a typical
11image build using the Yocto Project. The document also introduces how to
12configure a build for specific hardware. You will use Yocto Project to
13build a reference embedded OS called Poky.
14
15.. note::
16
17   -  The examples in this paper assume you are using a native Linux
18      system running a recent Ubuntu Linux distribution. If the machine
19      you want to use Yocto Project on to build an image
20      (:term:`Build Host`) is not
21      a native Linux system, you can still perform these steps by using
22      CROss PlatformS (CROPS) and setting up a Poky container. See the
23      :ref:`dev-manual/start:setting up to use cross platforms (crops)`
24      section
25      in the Yocto Project Development Tasks Manual for more
26      information.
27
28   -  You may use Windows Subsystem For Linux v2 to set up a build host
29      using Windows 10.
30
31      .. note::
32
33         The Yocto Project is not compatible with WSLv1, it is
34         compatible but not officially supported nor validated with
35         WSLv2, if you still decide to use WSL please upgrade to WSLv2.
36
37      See the :ref:`dev-manual/start:setting up to use windows
38      subsystem for linux (wslv2)` section in the Yocto Project Development
39      Tasks Manual for more information.
40
41If you want more conceptual or background information on the Yocto
42Project, see the :doc:`/overview-manual/index`.
43
44Compatible Linux Distribution
45=============================
46
47Make sure your :term:`Build Host` meets the
48following requirements:
49
50-  50 Gbytes of free disk space
51
52-  Runs a supported Linux distribution (i.e. recent releases of Fedora,
53   openSUSE, CentOS, Debian, or Ubuntu). For a list of Linux
54   distributions that support the Yocto Project, see the
55   :ref:`ref-manual/system-requirements:supported linux distributions`
56   section in the Yocto Project Reference Manual. For detailed
57   information on preparing your build host, see the
58   :ref:`dev-manual/start:preparing the build host`
59   section in the Yocto Project Development Tasks Manual.
60
61-
62
63   -  Git &MIN_GIT_VERSION; or greater
64   -  tar &MIN_TAR_VERSION; or greater
65   -  Python &MIN_PYTHON_VERSION; or greater.
66   -  gcc &MIN_GCC_VERSION; or greater.
67
68If your build host does not meet any of these three listed version
69requirements, you can take steps to prepare the system so that you
70can still use the Yocto Project. See the
71:ref:`ref-manual/system-requirements:required git, tar, python and gcc versions`
72section in the Yocto Project Reference Manual for information.
73
74Build Host Packages
75===================
76
77You must install essential host packages on your build host. The
78following command installs the host packages based on an Ubuntu
79distribution:
80
81.. code-block:: shell
82
83  $ sudo apt-get install &UBUNTU_HOST_PACKAGES_ESSENTIAL;
84
85.. note::
86
87   For host package requirements on all supported Linux distributions,
88   see the :ref:`ref-manual/system-requirements:required packages for the build host`
89   section in the Yocto Project Reference Manual.
90
91Use Git to Clone Poky
92=====================
93
94Once you complete the setup instructions for your machine, you need to
95get a copy of the Poky repository on your build host. Use the following
96commands to clone the Poky repository.
97
98.. code-block:: shell
99
100   $ git clone git://git.yoctoproject.org/poky
101   Cloning into 'poky'...
102   remote: Counting
103   objects: 432160, done. remote: Compressing objects: 100%
104   (102056/102056), done. remote: Total 432160 (delta 323116), reused
105   432037 (delta 323000) Receiving objects: 100% (432160/432160), 153.81 MiB | 8.54 MiB/s, done.
106   Resolving deltas: 100% (323116/323116), done.
107   Checking connectivity... done.
108
109Go to :yocto_wiki:`Releases wiki page </Releases>`, and choose a release
110codename (such as ``&DISTRO_NAME_NO_CAP;``), corresponding to either the
111latest stable release or a Long Term Support release.
112
113Then move to the ``poky`` directory and take a look at existing branches:
114
115.. code-block:: shell
116
117   $ cd poky
118   $ git branch -a
119   .
120   .
121   .
122   remotes/origin/HEAD -> origin/master
123   remotes/origin/dunfell
124   remotes/origin/dunfell-next
125   .
126   .
127   .
128   remotes/origin/gatesgarth
129   remotes/origin/gatesgarth-next
130   .
131   .
132   .
133   remotes/origin/master
134   remotes/origin/master-next
135   .
136   .
137   .
138
139
140For this example, check out the ``&DISTRO_NAME_NO_CAP;`` branch based on the
141``&DISTRO_NAME;`` release:
142
143.. code-block:: shell
144
145   $ git checkout -t origin/&DISTRO_NAME_NO_CAP; -b my-&DISTRO_NAME_NO_CAP;
146   Branch 'my-&DISTRO_NAME_NO_CAP;' set up to track remote branch '&DISTRO_NAME_NO_CAP;' from 'origin'.
147   Switched to a new branch 'my-&DISTRO_NAME_NO_CAP;'
148
149The previous Git checkout command creates a local branch named
150``my-&DISTRO_NAME_NO_CAP;``. The files available to you in that branch
151exactly match the repository's files in the ``&DISTRO_NAME_NO_CAP;``
152release branch.
153
154Note that you can regularly type the following command in the same directory
155to keep your local files in sync with the release branch:
156
157.. code-block:: shell
158
159   $ git pull
160
161For more options and information about accessing Yocto Project related
162repositories, see the
163:ref:`dev-manual/start:locating yocto project source files`
164section in the Yocto Project Development Tasks Manual.
165
166Building Your Image
167===================
168
169Use the following steps to build your image. The build process creates
170an entire Linux distribution, including the toolchain, from source.
171
172.. note::
173
174   -  If you are working behind a firewall and your build host is not
175      set up for proxies, you could encounter problems with the build
176      process when fetching source code (e.g. fetcher failures or Git
177      failures).
178
179   -  If you do not know your proxy settings, consult your local network
180      infrastructure resources and get that information. A good starting
181      point could also be to check your web browser settings. Finally,
182      you can find more information on the
183      ":yocto_wiki:`Working Behind a Network Proxy </Working_Behind_a_Network_Proxy>`"
184      page of the Yocto Project Wiki.
185
186#. **Initialize the Build Environment:** From within the ``poky``
187   directory, run the :ref:`ref-manual/structure:\`\`oe-init-build-env\`\``
188   environment
189   setup script to define Yocto Project's build environment on your
190   build host.
191
192   .. code-block:: shell
193
194      $ cd poky
195      $ source oe-init-build-env
196      You had no conf/local.conf file. This configuration file has therefore been
197      created for you with some default values. You may wish to edit it to, for
198      example, select a different MACHINE (target hardware). See conf/local.conf
199      for more information as common configuration options are commented.
200
201      You had no conf/bblayers.conf file. This configuration file has therefore
202      been created for you with some default values. To add additional metadata
203      layers into your configuration please add entries to conf/bblayers.conf.
204
205      The Yocto Project has extensive documentation about OE including a reference
206      manual which can be found at:
207          https://docs.yoctoproject.org
208
209      For more information about OpenEmbedded see their website:
210          https://www.openembedded.org/
211
212      ### Shell environment set up for builds. ###
213
214      You can now run 'bitbake <target>'
215
216      Common targets are:
217          core-image-minimal
218          core-image-full-cmdline
219          core-image-sato
220          core-image-weston
221          meta-toolchain
222          meta-ide-support
223
224      You can also run generated QEMU images with a command like 'runqemu qemux86-64'
225
226      Other commonly useful commands are:
227       - 'devtool' and 'recipetool' handle common recipe tasks
228       - 'bitbake-layers' handles common layer tasks
229       - 'oe-pkgdata-util' handles common target package tasks
230
231   Among other things, the script creates the :term:`Build Directory`, which is
232   ``build`` in this case and is located in the :term:`Source Directory`.  After
233   the script runs, your current working directory is set to the Build
234   Directory. Later, when the build completes, the Build Directory contains all the
235   files created during the build.
236
237#. **Examine Your Local Configuration File:** When you set up the build
238   environment, a local configuration file named ``local.conf`` becomes
239   available in a ``conf`` subdirectory of the Build Directory. For this
240   example, the defaults are set to build for a ``qemux86`` target,
241   which is suitable for emulation. The package manager used is set to
242   the RPM package manager.
243
244   .. tip::
245
246      You can significantly speed up your build and guard against fetcher
247      failures by using mirrors. To use mirrors, add these lines to your
248      local.conf file in the Build directory::
249
250         SSTATE_MIRRORS = "\
251         file://.* http://sstate.yoctoproject.org/dev/PATH;downloadfilename=PATH \n \
252         file://.* http://sstate.yoctoproject.org/&YOCTO_DOC_VERSION_MINUS_ONE;/PATH;downloadfilename=PATH \n \
253         file://.* http://sstate.yoctoproject.org/&YOCTO_DOC_VERSION;/PATH;downloadfilename=PATH \n \
254         "
255
256
257      The previous examples showed how to add sstate paths for Yocto Project
258      &YOCTO_DOC_VERSION_MINUS_ONE;, &YOCTO_DOC_VERSION;, and a development
259      area. For a complete index of sstate locations, see http://sstate.yoctoproject.org/.
260
261#. **Start the Build:** Continue with the following command to build an OS
262   image for the target, which is ``core-image-sato`` in this example:
263
264   .. code-block:: shell
265
266      $ bitbake core-image-sato
267
268   For information on using the ``bitbake`` command, see the
269   :ref:`overview-manual/concepts:bitbake` section in the Yocto Project Overview and
270   Concepts Manual, or see
271   :ref:`bitbake:bitbake-user-manual/bitbake-user-manual-intro:the bitbake command`
272   in the BitBake User Manual.
273
274#. **Simulate Your Image Using QEMU:** Once this particular image is
275   built, you can start QEMU, which is a Quick EMUlator that ships with
276   the Yocto Project:
277
278   .. code-block:: shell
279
280      $ runqemu qemux86-64
281
282   If you want to learn more about running QEMU, see the
283   :ref:`dev-manual/qemu:using the quick emulator (qemu)` chapter in
284   the Yocto Project Development Tasks Manual.
285
286#. **Exit QEMU:** Exit QEMU by either clicking on the shutdown icon or by typing
287   ``Ctrl-C`` in the QEMU transcript window from which you evoked QEMU.
288
289Customizing Your Build for Specific Hardware
290============================================
291
292So far, all you have done is quickly built an image suitable for
293emulation only. This section shows you how to customize your build for
294specific hardware by adding a hardware layer into the Yocto Project
295development environment.
296
297In general, layers are repositories that contain related sets of
298instructions and configurations that tell the Yocto Project what to do.
299Isolating related metadata into functionally specific layers facilitates
300modular development and makes it easier to reuse the layer metadata.
301
302.. note::
303
304   By convention, layer names start with the string "meta-".
305
306Follow these steps to add a hardware layer:
307
308#. **Find a Layer:** Many hardware layers are available. The Yocto Project
309   :yocto_git:`Source Repositories <>` has many hardware layers.
310   This example adds the
311   `meta-altera <https://github.com/kraj/meta-altera>`__ hardware layer.
312
313#. **Clone the Layer:** Use Git to make a local copy of the layer on your
314   machine. You can put the copy in the top level of the copy of the
315   Poky repository created earlier:
316
317   .. code-block:: shell
318
319      $ cd poky
320      $ git clone https://github.com/kraj/meta-altera.git
321      Cloning into 'meta-altera'...
322      remote: Counting objects: 25170, done.
323      remote: Compressing objects: 100% (350/350), done.
324      remote: Total 25170 (delta 645), reused 719 (delta 538), pack-reused 24219
325      Receiving objects: 100% (25170/25170), 41.02 MiB | 1.64 MiB/s, done.
326      Resolving deltas: 100% (13385/13385), done.
327      Checking connectivity... done.
328
329   The hardware layer is now available
330   next to other layers inside the Poky reference repository on your build
331   host as ``meta-altera`` and contains all the metadata needed to
332   support hardware from Altera, which is owned by Intel.
333
334   .. note::
335
336      It is recommended for layers to have a branch per Yocto Project release.
337      Please make sure to checkout the layer branch supporting the Yocto Project
338      release you're using.
339
340#. **Change the Configuration to Build for a Specific Machine:** The
341   :term:`MACHINE` variable in the
342   ``local.conf`` file specifies the machine for the build. For this
343   example, set the :term:`MACHINE` variable to ``cyclone5``. These
344   configurations are used:
345   https://github.com/kraj/meta-altera/blob/master/conf/machine/cyclone5.conf.
346
347   .. note::
348
349      See the "Examine Your Local Configuration File" step earlier for more
350      information on configuring the build.
351
352#. **Add Your Layer to the Layer Configuration File:** Before you can use
353   a layer during a build, you must add it to your ``bblayers.conf``
354   file, which is found in the
355   :term:`Build Directory` ``conf``
356   directory.
357
358   Use the ``bitbake-layers add-layer`` command to add the layer to the
359   configuration file:
360
361   .. code-block:: shell
362
363      $ cd poky/build
364      $ bitbake-layers add-layer ../meta-altera
365      NOTE: Starting bitbake server...
366      Parsing recipes: 100% |##################################################################| Time: 0:00:32
367      Parsing of 918 .bb files complete (0 cached, 918 parsed). 1401 targets,
368      123 skipped, 0 masked, 0 errors.
369
370   You can find
371   more information on adding layers in the
372   :ref:`dev-manual/common-tasks:adding a layer using the \`\`bitbake-layers\`\` script`
373   section.
374
375Completing these steps has added the ``meta-altera`` layer to your Yocto
376Project development environment and configured it to build for the
377``cyclone5`` machine.
378
379.. note::
380
381   The previous steps are for demonstration purposes only. If you were
382   to attempt to build an image for the ``cyclone5`` machine, you should
383   read the Altera ``README``.
384
385Creating Your Own General Layer
386===============================
387
388Maybe you have an application or specific set of behaviors you need to
389isolate. You can create your own general layer using the
390``bitbake-layers create-layer`` command. The tool automates layer
391creation by setting up a subdirectory with a ``layer.conf``
392configuration file, a ``recipes-example`` subdirectory that contains an
393``example.bb`` recipe, a licensing file, and a ``README``.
394
395The following commands run the tool to create a layer named
396``meta-mylayer`` in the ``poky`` directory:
397
398.. code-block:: shell
399
400   $ cd poky
401   $ bitbake-layers create-layer meta-mylayer
402   NOTE: Starting bitbake server...
403   Add your new layer with 'bitbake-layers add-layer meta-mylayer'
404
405For more information
406on layers and how to create them, see the
407:ref:`dev-manual/common-tasks:creating a general layer using the \`\`bitbake-layers\`\` script`
408section in the Yocto Project Development Tasks Manual.
409
410Where To Go Next
411================
412
413Now that you have experienced using the Yocto Project, you might be
414asking yourself "What now?". The Yocto Project has many sources of
415information including the website, wiki pages, and user manuals:
416
417-  **Website:** The :yocto_home:`Yocto Project Website <>` provides
418   background information, the latest builds, breaking news, full
419   development documentation, and access to a rich Yocto Project
420   Development Community into which you can tap.
421
422-  **Developer Screencast:** The `Getting Started with the Yocto Project -
423   New Developer Screencast Tutorial <https://vimeo.com/36450321>`__
424   provides a 30-minute video created for users unfamiliar with the
425   Yocto Project but familiar with Linux build hosts. While this
426   screencast is somewhat dated, the introductory and fundamental
427   concepts are useful for the beginner.
428
429-  **Yocto Project Overview and Concepts Manual:** The
430   :doc:`/overview-manual/index` is a great
431   place to start to learn about the Yocto Project. This manual
432   introduces you to the Yocto Project and its development environment.
433   The manual also provides conceptual information for various aspects
434   of the Yocto Project.
435
436-  **Yocto Project Wiki:** The :yocto_wiki:`Yocto Project Wiki <>`
437   provides additional information on where to go next when ramping up
438   with the Yocto Project, release information, project planning, and QA
439   information.
440
441-  **Yocto Project Mailing Lists:** Related mailing lists provide a forum
442   for discussion, patch submission and announcements. There are several
443   mailing lists grouped by topic. See the
444   :ref:`ref-manual/resources:mailing lists`
445   section in the Yocto Project Reference Manual for a complete list of
446   Yocto Project mailing lists.
447
448-  **Comprehensive List of Links and Other Documentation:** The
449   :ref:`ref-manual/resources:links and related documentation`
450   section in the Yocto Project Reference Manual provides a
451   comprehensive list of all related links and other user documentation.
452
453.. include:: /boilerplate.rst
454