ref-manual: classes: kernel: document automatic defconfig usage

Since a very long time the kernel bbclass uses a defconfig file from
SRC_URI automatically. Document this feature.

(From yocto-docs rev: d99f7913ca3fc546a9714a38f3e22403261c4015)

Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Reviewed-by: Michael Opdenacker <michael.opdenacker@bootlin.com>
Signed-off-by: Steve Sakoman <steve@sakoman.com>
This commit is contained in:
Luca Ceresoli
2023-05-05 11:10:06 +02:00
committed by Steve Sakoman
parent cd1e4106e6
commit 30d015c636

View File

@@ -1532,6 +1532,13 @@ code to build all kernel trees. All needed headers are staged into the
:term:`STAGING_KERNEL_DIR` directory to allow out-of-tree module builds
using the :ref:`ref-classes-module` class.
If a file named ``defconfig`` is listed in :term:`SRC_URI`, then by default
:ref:`ref-tasks-configure` copies it as ``.config`` in the build directory,
so it is automatically used as the kernel configuration for the build. This
copy is not performed in case ``.config`` already exists there: this allows
recipes to produce a configuration by other means in
``do_configure:prepend``.
Each built kernel module is packaged separately and inter-module
dependencies are created by parsing the ``modinfo`` output. If all modules
are required, then installing the ``kernel-modules`` package installs all