Contributing
============


Getting Started
---------------

-  Make sure you have a Github account and you are logged on
   `developer.trustedfirmware.org`_.
-  Send an email to the |TFACMF-MAIL-LIST| about your work. This gives
   everyone visibility of whether others are working on something similar.
-  Clone the `TFACMF repository`_ on your own machine as suggested in the
   :ref:`User Guide`.
-  Create a local topic branch based on the `TFACMF repository`_ ``master``
   branch.

Making Changes
--------------

-  Make commits of logical units. See these general `Git guidelines`_ for
   contributing to a project.
-  Follow the :ref:`Coding Style & Guidelines`.
-  Keep the commits on topic. If you need to fix another bug or make another
   enhancement, please create a separate change.
-  Avoid long commit series. If you do have a long series, consider whether
   some commits should be squashed together or addressed in a separate topic.
-  Make sure your commit messages are in the proper format.
-  Where appropriate, please update the documentation.

   -  Consider whether the :ref:`User Guide` or other in-source documentation
      needs updating.
   -  Ensure that each changed file has the correct copyright and license
      information. Files that entirely consist of contributions to this
      project should have a copyright notice and BSD-3-Clause SPDX license
      identifier of the form as shown in :ref:`license`. Files that contain
      changes to imported Third Party IP files should retain their original
      copyright and license notices. For significant contributions you may
      add your own copyright notice in following format:

      ::

          Portions copyright (c) [XXXX-]YYYY, <OWNER>. All rights reserved.

      where XXXX is the year of first contribution (if different to YYYY) and
      YYYY is the year of most recent contribution. <OWNER> is your name or
      your company name.
   -  If you are submitting new files that you intend to be the technical
      sub-maintainer for (for example, a new platform port), then also update
      the :ref:`maintainers` file.
   -  For topics with multiple commits, you should make all documentation
      changes (and nothing else) in the last commit of the series. Otherwise,
      include the documentation changes within the single commit.

-  Please test your changes.

Submitting Changes
------------------

-  Ensure that each commit in the series has at least one ``Signed-off-by:``
   line, using your real name and email address. The names in the
   ``Signed-off-by:`` and ``Author:`` lines must match. If anyone else
   contributes to the commit, they must also add their own ``Signed-off-by:``
   line. By adding this line the contributor certifies the contribution is made
   under the terms of the
   :download:`Developer Certificate of Origin <../dco.txt>`.

   More details may be found in the `Gerrit Signed-off-by Lines guidelines`_.

-  Ensure that each commit also has a unique ``Change-Id:`` line. If you have
   cloned the repository with the "`Clone with commit-msg hook`" clone method
   (as advised on the :ref:`User Guide`), this should already be the case.

   More details may be found in the `Gerrit Change-Ids documentation`_.

-  Submit your changes for review at https://review.trustedfirmware.org
   targeting the ``integration`` branch.

   -  The changes will then undergo further review and testing by the
      :ref:`maintainers`. Any review comments will be made directly on your
      patch. This may require you to do some rework.

   Refer to the `Gerrit Uploading Changes documentation`_ for more details.

-  When the changes are accepted, the :ref:`maintainers` will integrate them.

   -  Typically, the :ref:`maintainers` will merge the changes into the
      ``integration`` branch.
   -  If the changes are not based on a sufficiently-recent commit, or if they
      cannot be automatically rebased, then the :ref:`maintainers` may rebase it
      on the ``master`` branch or ask you to do so.
   -  After final integration testing, the changes will make their way into the
      ``master`` branch. If a problem is found during integration, the merge
      commit will be removed from the ``integration`` branch and the
      :ref:`maintainers` will ask you to create a new patch set to resolve the
      problem.

--------------

.. _developer.trustedfirmware.org: https://developer.trustedfirmware.org
.. _Git guidelines: http://git-scm.com/book/ch5-2.html
.. _Gerrit Uploading Changes documentation: https://review.trustedfirmware.org/Documentation/user-upload.html
.. _Gerrit Signed-off-by Lines guidelines: https://review.trustedfirmware.org/Documentation/user-signedoffby.html
.. _Gerrit Change-Ids documentation: https://review.trustedfirmware.org/Documentation/user-changeid.html

*Copyright (c) 2019-2020, Arm Limited and Contributors. All rights reserved.*

SPDX-License-Identifier: BSD-3-Clause