[libcamera-devel] [PATCH v2] README: Add unit tests instructions

[Kieran Bingham]

The unit tests require kernel modules to be loaded to support the
virtual test cameras. Add notes to the readme to highlight that it can
be done, and what kernel configurations are required.

Suggested-by: William Salmon <pointswaves at gmail.com>
Signed-off-by: Kieran Bingham <kieran.bingham at ideasonboard.com>
---

v2:
 - Reword small fixes from Laurent
 - Move to contributing.rst

 Documentation/contributing.rst | 41 ++++++++++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)

diff --git a/Documentation/contributing.rst b/Documentation/contributing.rst
index 2f0b4921f7e6..27c77558a6e6 100644
--- a/Documentation/contributing.rst
+++ b/Documentation/contributing.rst
@@ -59,6 +59,47 @@ uses `Doxygen`_.  Please make sure to document all code during development.
 .. _Sphinx: https://www.sphinx-doc.org
 .. _Doxygen: https://www.doxygen.nl
 
+Running the unit tests
+----------------------
+
+When submitting patches, it is recommended to run the unit tests. The unit
+tests rely on kernel drivers which produce virtual devices. These can be either
+built into the kernel, or provided as modules (=y or =m):
+
+.. code::
+
+    CONFIG_MEDIA_TEST_SUPPORT=y
+    CONFIG_V4L_TEST_DRIVERS=y
+
+    CONFIG_VIDEO_VIM2M=m
+    CONFIG_VIDEO_VIMC=m
+    CONFIG_VIDEO_VIVID=m
+
+If the kernel provides the test drivers as modules, they need to be loaded
+before running the tests:
+
+.. code::
+
+    sudo modprobe vimc
+    sudo modprobe vivid
+    sudo modprobe vim2m
+
+Make sure your build configuration has tests enabled by running the following
+in the build directory:
+
+.. code::
+
+    meson configure -Dtest=true
+
+Enabling 'test=true' will implicitly add the VIMC test pipeline handler to the
+build configuration.
+
+Then the tests can be run with:
+
+.. code::
+
+  ninja -C build test
+
 Submitting Patches
 ------------------
 
-- 
2.34.1