=============
Getting KUnit
=============

If you're working on Linux 5.5+, you have KUnit.
Otherwise, you'll want to backport the patches, which should all begin with ``"kunit: "``.

An option of last resort is to use the deprecated and incompatible
``kunit/alpha/master`` branch.
See :ref:`alpha-master` below for more details.

.. _download-links:

Where are these versions?
=========================

Upstream
--------

KUnit can be found in Linux 5.5 and newer.

- Code: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/
- `Usage <../third_party/kernel/docs/usage.html>`__ - for a more detailed explanation of KUnit features
- `API <../third_party/kernel/docs/api>`__ - for the list of KUnit APIs used for testing

The KUnit code itself is primarily found in the `lib/kunit <https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/lib/kunit>`__
directory.

.. _alpha-master:

Deprecated
----------

This is where KUnit development was done prior to getting upstreamed, but all
development on it has since ceased.

It has a couple of features that haven't made their way in the upstream version
of KUnit yet, namely:

- Class mocking
- Function mocking
- Hardware/platform faking
- Error recovery

.. note::
  Tests written against the ``kunit/alpha/master`` branch will *not* be
  directly compatible with the upstream version, however.  You can set
  ``CONFIG_KUNIT_USE_UPSTREAM_NAMES=y`` to make it act a bit more like the
  upstream version, see `this patch series
  <https://kunit-review.googlesource.com/c/linux/+/4029/>`_ for details.

The old, deprecated branch is stored in a Google-hosted gerrit instance.

- Code: https://kunit.googlesource.com/linux/+/kunit/alpha/master.
- `Usage <../third_party/stable_kernel/docs/usage.html>`__ - for a more detailed explanation of KUnit features
- `API <../third_party/stable_kernel/docs/api>`__ - for the list of KUnit APIs used for testing
- kunitconfig file: https://kunit.googlesource.com/kunitconfig/+/refs/heads/kunit/alpha/master/kunitconfig