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          http://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-sato
219          meta-toolchain
220          meta-ide-support
221
222      You can also run generated QEMU images with a command like 'runqemu qemux86-64'
223
224   Among other things, the script creates the :term:`Build Directory`, which is
225   ``build`` in this case and is located in the :term:`Source Directory`.  After
226   the script runs, your current working directory is set to the Build
227   Directory. Later, when the build completes, the Build Directory contains all the
228   files created during the build.
229
230#. **Examine Your Local Configuration File:** When you set up the build
231   environment, a local configuration file named ``local.conf`` becomes
232   available in a ``conf`` subdirectory of the Build Directory. For this
233   example, the defaults are set to build for a ``qemux86`` target,
234   which is suitable for emulation. The package manager used is set to
235   the RPM package manager.
236
237   .. tip::
238
239      You can significantly speed up your build and guard against fetcher
240      failures by using mirrors. To use mirrors, add these lines to your
241      local.conf file in the Build directory::
242
243         SSTATE_MIRRORS = "\
244         file://.* http://sstate.yoctoproject.org/dev/PATH;downloadfilename=PATH \n \
245         file://.* http://sstate.yoctoproject.org/&YOCTO_DOC_VERSION_MINUS_ONE;/PATH;downloadfilename=PATH \n \
246         file://.* http://sstate.yoctoproject.org/&YOCTO_DOC_VERSION;/PATH;downloadfilename=PATH \n \
247         "
248
249
250      The previous examples showed how to add sstate paths for Yocto Project
251      &YOCTO_DOC_VERSION_MINUS_ONE;, &YOCTO_DOC_VERSION;, and a development
252      area. For a complete index of sstate locations, see http://sstate.yoctoproject.org/.
253
254#. **Start the Build:** Continue with the following command to build an OS
255   image for the target, which is ``core-image-sato`` in this example:
256
257   .. code-block:: shell
258
259      $ bitbake core-image-sato
260
261   For information on using the ``bitbake`` command, see the
262   :ref:`overview-manual/concepts:bitbake` section in the Yocto Project Overview and
263   Concepts Manual, or see the ":ref:`BitBake Command
264   <bitbake:bitbake-user-manual/bitbake-user-manual-intro:the bitbake command>`" section in the BitBake User Manual.
265
266#. **Simulate Your Image Using QEMU:** Once this particular image is
267   built, you can start QEMU, which is a Quick EMUlator that ships with
268   the Yocto Project:
269
270   .. code-block:: shell
271
272      $ runqemu qemux86-64
273
274   If you want to learn more about running QEMU, see the
275   :ref:`dev-manual/qemu:using the quick emulator (qemu)` chapter in
276   the Yocto Project Development Tasks Manual.
277
278#. **Exit QEMU:** Exit QEMU by either clicking on the shutdown icon or by typing
279   ``Ctrl-C`` in the QEMU transcript window from which you evoked QEMU.
280
281Customizing Your Build for Specific Hardware
282============================================
283
284So far, all you have done is quickly built an image suitable for
285emulation only. This section shows you how to customize your build for
286specific hardware by adding a hardware layer into the Yocto Project
287development environment.
288
289In general, layers are repositories that contain related sets of
290instructions and configurations that tell the Yocto Project what to do.
291Isolating related metadata into functionally specific layers facilitates
292modular development and makes it easier to reuse the layer metadata.
293
294.. note::
295
296   By convention, layer names start with the string "meta-".
297
298Follow these steps to add a hardware layer:
299
300#. **Find a Layer:** Many hardware layers are available. The Yocto Project
301   :yocto_git:`Source Repositories <>` has many hardware layers.
302   This example adds the
303   `meta-altera <https://github.com/kraj/meta-altera>`__ hardware layer.
304
305#. **Clone the Layer:** Use Git to make a local copy of the layer on your
306   machine. You can put the copy in the top level of the copy of the
307   Poky repository created earlier:
308
309   .. code-block:: shell
310
311      $ cd poky
312      $ git clone https://github.com/kraj/meta-altera.git
313      Cloning into 'meta-altera'...
314      remote: Counting objects: 25170, done.
315      remote: Compressing objects: 100% (350/350), done.
316      remote: Total 25170 (delta 645), reused 719 (delta 538), pack-reused 24219
317      Receiving objects: 100% (25170/25170), 41.02 MiB | 1.64 MiB/s, done.
318      Resolving deltas: 100% (13385/13385), done.
319      Checking connectivity... done.
320
321   The hardware layer is now available
322   next to other layers inside the Poky reference repository on your build
323   host as ``meta-altera`` and contains all the metadata needed to
324   support hardware from Altera, which is owned by Intel.
325
326   .. note::
327
328      It is recommended for layers to have a branch per Yocto Project release.
329      Please make sure to checkout the layer branch supporting the Yocto Project
330      release you're using.
331
332#. **Change the Configuration to Build for a Specific Machine:** The
333   :term:`MACHINE` variable in the
334   ``local.conf`` file specifies the machine for the build. For this
335   example, set the :term:`MACHINE` variable to ``cyclone5``. These
336   configurations are used:
337   https://github.com/kraj/meta-altera/blob/master/conf/machine/cyclone5.conf.
338
339   .. note::
340
341      See the "Examine Your Local Configuration File" step earlier for more
342      information on configuring the build.
343
344#. **Add Your Layer to the Layer Configuration File:** Before you can use
345   a layer during a build, you must add it to your ``bblayers.conf``
346   file, which is found in the
347   :term:`Build Directory` ``conf``
348   directory.
349
350   Use the ``bitbake-layers add-layer`` command to add the layer to the
351   configuration file:
352
353   .. code-block:: shell
354
355      $ cd poky/build
356      $ bitbake-layers add-layer ../meta-altera
357      NOTE: Starting bitbake server...
358      Parsing recipes: 100% |##################################################################| Time: 0:00:32
359      Parsing of 918 .bb files complete (0 cached, 918 parsed). 1401 targets,
360      123 skipped, 0 masked, 0 errors.
361
362   You can find
363   more information on adding layers in the
364   :ref:`dev-manual/common-tasks:adding a layer using the \`\`bitbake-layers\`\` script`
365   section.
366
367Completing these steps has added the ``meta-altera`` layer to your Yocto
368Project development environment and configured it to build for the
369``cyclone5`` machine.
370
371.. note::
372
373   The previous steps are for demonstration purposes only. If you were
374   to attempt to build an image for the ``cyclone5`` machine, you should
375   read the Altera ``README``.
376
377Creating Your Own General Layer
378===============================
379
380Maybe you have an application or specific set of behaviors you need to
381isolate. You can create your own general layer using the
382``bitbake-layers create-layer`` command. The tool automates layer
383creation by setting up a subdirectory with a ``layer.conf``
384configuration file, a ``recipes-example`` subdirectory that contains an
385``example.bb`` recipe, a licensing file, and a ``README``.
386
387The following commands run the tool to create a layer named
388``meta-mylayer`` in the ``poky`` directory:
389
390.. code-block:: shell
391
392   $ cd poky
393   $ bitbake-layers create-layer meta-mylayer
394   NOTE: Starting bitbake server...
395   Add your new layer with 'bitbake-layers add-layer meta-mylayer'
396
397For more information
398on layers and how to create them, see the
399:ref:`dev-manual/common-tasks:creating a general layer using the \`\`bitbake-layers\`\` script`
400section in the Yocto Project Development Tasks Manual.
401
402Where To Go Next
403================
404
405Now that you have experienced using the Yocto Project, you might be
406asking yourself "What now?". The Yocto Project has many sources of
407information including the website, wiki pages, and user manuals:
408
409-  **Website:** The :yocto_home:`Yocto Project Website <>` provides
410   background information, the latest builds, breaking news, full
411   development documentation, and access to a rich Yocto Project
412   Development Community into which you can tap.
413
414-  **Developer Screencast:** The `Getting Started with the Yocto Project -
415   New Developer Screencast Tutorial <https://vimeo.com/36450321>`__
416   provides a 30-minute video created for users unfamiliar with the
417   Yocto Project but familiar with Linux build hosts. While this
418   screencast is somewhat dated, the introductory and fundamental
419   concepts are useful for the beginner.
420
421-  **Yocto Project Overview and Concepts Manual:** The
422   :doc:`/overview-manual/index` is a great
423   place to start to learn about the Yocto Project. This manual
424   introduces you to the Yocto Project and its development environment.
425   The manual also provides conceptual information for various aspects
426   of the Yocto Project.
427
428-  **Yocto Project Wiki:** The :yocto_wiki:`Yocto Project Wiki <>`
429   provides additional information on where to go next when ramping up
430   with the Yocto Project, release information, project planning, and QA
431   information.
432
433-  **Yocto Project Mailing Lists:** Related mailing lists provide a forum
434   for discussion, patch submission and announcements. There are several
435   mailing lists grouped by topic. See the
436   :ref:`ref-manual/resources:mailing lists`
437   section in the Yocto Project Reference Manual for a complete list of
438   Yocto Project mailing lists.
439
440-  **Comprehensive List of Links and Other Documentation:** The
441   :ref:`ref-manual/resources:links and related documentation`
442   section in the Yocto Project Reference Manual provides a
443   comprehensive list of all related links and other user documentation.
444
445.. include:: /boilerplate.rst
446