17 The :term:`BitBake` task executor
23 BitBake handles the parsing and execution of the data files. The data
35 BitBake knows how to combine multiple data sources together and refers
46 BitBake  section in Yocto Project Components
49 BitBake is the tool at the heart of the :term:`OpenEmbedded Build System`
54 This section briefly introduces BitBake. If you want more information on
55 BitBake, see the :doc:`BitBake User Manual <bitbake:index>`.
57 To see a list of the options BitBake supports, use either of the
60    $ bitbake -h
61    $ bitbake --help
63 The most common usage for BitBake is ``bitbake recipename``, where
70    $ bitbake matchbox-desktop
73 versions of ``matchbox-desktop`` might exist. BitBake chooses the one
75 about how BitBake chooses between different target versions and
77 ":ref:`bitbake:bitbake-user-manual/bitbake-user-manual-execution:preferences`" section
78 of the BitBake User Manual.
80 BitBake also tries to execute any dependent tasks first. So for example,
81 before building ``matchbox-desktop``, BitBake would build a cross
84 A useful BitBake option to consider is the ``-k`` or ``--continue``
85 option. This option instructs BitBake to try and continue processing the
148 Conforming to a known structure allows BitBake to make assumptions
150 procedures and learn about tools (i.e. ``bitbake-layers``) for creating
162 is BitBake, the task executor.
182    :term:`BitBake`. This block expands
183    on how BitBake fetches source, applies patches, completes
198    produced along with an image or separately with BitBake.
204 you can tell BitBake the target architecture for which you are building
214 BitBake needs some basic configuration files in order to complete a
238 already exist. BitBake uses the Build Directory for all its work during
248 :term:`OpenEmbedded-Core (OE-Core)` and BitBake
306 The ``bblayers.conf`` file tells BitBake what layers you want considered
329    to include the path to a ``conf/site.conf``. Then, when BitBake looks
345 When you launch your build with the ``bitbake target`` command, BitBake
352 ":doc:`bitbake:bitbake-user-manual/bitbake-user-manual-metadata`" chapter
353 of the BitBake User Manual. Because the files are parsed in a specific
364 BitBake's global behavior. This section takes a closer look at the
429 BitBake uses the ``conf/bblayers.conf`` file, which is part of the user
439 ``conf/distro/distro.conf`` override similar settings that BitBake finds
528 BitBake uses the :term:`SRC_URI`
582 :ref:`bitbake:bitbake-user-manual/bitbake-user-manual-fetching:fetchers` employing various Source
586 BitBake uses the :term:`SRC_URI`
598 When fetching a repository, BitBake uses the
608 these, respectively. BitBake checks pre-mirrors before looking upstream
666 BitBake uses the
682 BitBake Tool
686 :term:`BitBake` to produce images and
689 the BitBake area consists of several functional areas. This section takes a
694    Documentation for the BitBake tool is available separately. See the
695    BitBake User Manual
696    for reference material on BitBake.
789 Once source code is fetched and unpacked, BitBake locates patch files
806 BitBake finds and applies multiple patches for a single recipe in the
829 After source code is patched, BitBake executes tasks that configure and
871    BitBake compiles the source using the
878 -  *do_install*: After compilation completes, BitBake executes the
968 system uses BitBake to generate the root filesystem image:
1084 The OpenEmbedded build system uses BitBake to generate the Software
1132 For each task that completes successfully, BitBake writes a stamp file
1146 To determine if a task needs to be rerun, BitBake checks if a stamp file
1156    BitBake avoids rerunning any task that has a valid stamp file, not just
1172 mark it with the :ref:`nostamp <bitbake:bitbake-user-manual/bitbake-user-manual-metadata:variable f…
1183 The description of tasks so far assumes that BitBake needs to build
1184 everything and no available prebuilt objects exist. BitBake does support
1197 version of the task where instead of building something, BitBake can
1217 and other preceding tasks. For example, if BitBake runs
1221 ``do_package`` needs to be run, BitBake needs to run those other tasks.
1227 from sstate, BitBake does not need the ``do_package`` task data.
1229 To handle all these complexities, BitBake runs in two phases. The first
1230 is the "setscene" stage. During this stage, BitBake first checks the
1231 sstate cache for any targets it is planning to build. BitBake does a
1259 <overview-manual/concepts:openembedded build system concepts>` that BitBake
1319 SDK (e.g. ``bitbake -c populate_sdk_ext`` imagename) or a standard SDK
1320 (e.g. ``bitbake -c populate_sdk`` imagename). This section takes a
1403    ``bitbake -c populate_sdk imagename`` to create the SDK, a set of
1447 :term:`BitBake` to create an image, the
1450 BitBake uses to compile source files when creating the target image. You
1452 cross-compiler that is used internally within BitBake only.
1482    BitBake uses when it builds an image for a targeted device.
1561 unless :term:`BitBake` can determine
1623 When determining what parts of the system need to be built, BitBake
1691 Equally, there are cases where you need to add dependencies BitBake is
1700 As an example, consider a case with in-line Python where BitBake is not
1702 ``-DDD``), BitBake produces output when it discovers something for which
1719 and the dependent task hashes can be influenced. Within the BitBake
1720 configuration file, you can give BitBake some extra information to help
1742 in BitBake. This means that behavior is unchanged from previous
1744 through this setting in the ``bitbake.conf`` file::
1850   information, see the ":ref:`bitbake:bitbake-user-manual/bitbake-user-manual-execution:setscene`"
1851   section in the BitBake User Manual.
1856 …For more information, see the ":ref:`bitbake:bitbake-user-manual/bitbake-user-manual-metadata:vari…
1857    section in the BitBake
1875    ":ref:`bitbake:bitbake-user-manual/bitbake-user-manual-execution:the task list`"
1876    section in the BitBake User Manual for more information on the
1919 acceleration phase. BitBake goes through this phase before the main
1937 The above section explained how BitBake skips the execution of tasks
1945 To keep track of such equivalence, BitBake has to manage three hashes
1965 When Hash Equivalence is enabled, BitBake computes the task hash
1976 let BitBake know whether this output hash is the same as a previously
1979 If the output hash is already known, BitBake will update the task's
1982 task hash, and BitBake will be able to retrieve their output from
1994 tasks in BitBake's run queue doesn't have to propagate to all the
1998 recorded output, BitBake can safely retrieve all the downstream
2027 -  :term:`bitbake:BB_HASHSERVE`, specifying a local or remote Hash
2033 -  :term:`bitbake:BB_SIGNATURE_HANDLER`, which must be set  to ``OEEquivHash``.
2149       bitbake.conf) includes "${PN}".
2159 of a ``[``\ :ref:`deptask <bitbake:bitbake-user-manual/bitbake-user-manual-metadata:variable flags>…
2177 to require :term:`BitBake` to run as
2189 the BitBake keyword/variable flag that requests a fake root environment
2220 :term:`FAKEROOT* <bitbake:FAKEROOT>` variables in the
2221 BitBake User Manual. You can also reference the "`Why Not