1Contributor's Guide 2=================== 3 4Getting Started 5--------------- 6 7- Make sure you have a Github account and you are logged on both 8 `developer.trustedfirmware.org`_ and `review.trustedfirmware.org`_. 9 10- If you plan to contribute a major piece of work, it is usually a good idea to 11 start a discussion around it on the mailing list. This gives everyone 12 visibility of what is coming up, you might learn that somebody else is 13 already working on something similar or the community might be able to 14 provide some early input to help shaping the design of the feature. 15 16 If you intend to include Third Party IP in your contribution, please mention 17 it explicitly in the email thread and ensure that the changes that include 18 Third Party IP are made in a separate patch (or patch series). 19 20- Clone `Trusted Firmware-A`_ on your own machine as described in 21 :ref:`prerequisites_get_source`. 22 23- Create a local topic branch based on the `Trusted Firmware-A`_ ``master`` 24 branch. 25 26Making Changes 27-------------- 28 29- Make commits of logical units. See these general `Git guidelines`_ for 30 contributing to a project. 31 32- Ensure your commit messages comply with the `Conventional Commits`_ 33 specification: 34 35 .. code:: 36 37 <type>[optional scope]: <description> 38 39 [optional body] 40 41 [optional footer(s)] 42 43 You can use the tooling installed by the optional steps in the 44 :ref:`prerequisites <Prerequisites>` guide to validate this locally. 45 46- Keep the commits on topic. If you need to fix another bug or make another 47 enhancement, please address it on a separate topic branch. 48 49- Split the patch in manageable units. Small patches are usually easier to 50 review so this will speed up the review process. 51 52- Avoid long commit series. If you do have a long series, consider whether 53 some commits should be squashed together or addressed in a separate topic. 54 55- Ensure that each commit in the series has at least one ``Signed-off-by:`` 56 line, using your real name and email address. The names in the 57 ``Signed-off-by:`` and ``Commit:`` lines must match. By adding this line the 58 contributor certifies the contribution is made under the terms of the 59 :download:`Developer Certificate of Origin <../../dco.txt>`. 60 61 There might be multiple ``Signed-off-by:`` lines, depending on the history 62 of the patch. 63 64 More details may be found in the `Gerrit Signed-off-by Lines guidelines`_. 65 66- Ensure that each commit also has a unique ``Change-Id:`` line. If you have 67 cloned the repository with the "`Clone with commit-msg hook`" clone method 68 (following the :ref:`Prerequisites` document), this should already be the 69 case. 70 71 More details may be found in the `Gerrit Change-Ids documentation`_. 72 73- Write informative and comprehensive commit messages. A good commit message 74 provides all the background information needed for reviewers to understand 75 the intent and rationale of the patch. This information is also useful for 76 future reference. 77 78 For example: 79 80 - What does the patch do? 81 - What motivated it? 82 - What impact does it have? 83 - How was it tested? 84 - Have alternatives been considered? Why did you choose this approach over 85 another one? 86 - If it fixes an `issue`_, include a reference. 87 88- Follow the :ref:`Coding Style` and :ref:`Coding Guidelines`. 89 90 - Use the checkpatch.pl script provided with the Linux source tree. A 91 Makefile target is provided for convenience, see :ref:`this 92 section<automatic-compliance-checking>` for more details. 93 94- Where appropriate, please update the documentation. 95 96 - Consider whether the :ref:`Porting Guide`, :ref:`Firmware Design` document 97 or other in-source documentation needs updating. 98 99 - If you are submitting new files that you intend to be the code owner for 100 (for example, a new platform port), then also update the 101 :ref:`code owners` file. 102 103 - For topics with multiple commits, you should make all documentation changes 104 (and nothing else) in the last commit of the series. Otherwise, include 105 the documentation changes within the single commit. 106 107.. _copyright-license-guidance: 108 109- Ensure that each changed file has the correct copyright and license 110 information. Files that entirely consist of contributions to this project 111 should have a copyright notice and BSD-3-Clause SPDX license identifier of 112 the form as shown in :ref:`license`. Files that contain changes to imported 113 Third Party IP files should retain their original copyright and license 114 notices. 115 116 For significant contributions you may add your own copyright notice in the 117 following format: 118 119 :: 120 121 Portions copyright (c) [XXXX-]YYYY, <OWNER>. All rights reserved. 122 123 where XXXX is the year of first contribution (if different to YYYY) and YYYY 124 is the year of most recent contribution. <OWNER> is your name or your company 125 name. 126 127- Ensure that each patch in the patch series compiles in all supported 128 configurations. Patches which do not compile will not be merged. 129 130- Please test your changes. As a minimum, ensure that Linux boots on the 131 Foundation FVP. See :ref:`Arm Fixed Virtual Platforms (FVP)` for more 132 information. For more extensive testing, consider running the `TF-A Tests`_ 133 against your patches. 134 135- Ensure that all CI automated tests pass. Failures should be fixed. They might 136 block a patch, depending on how critical they are. 137 138Submitting Changes 139------------------ 140 141- Submit your changes for review at https://review.trustedfirmware.org 142 targeting the ``integration`` branch. 143 144- Add reviewers for your patch: 145 146 - At least one code owner for each module modified by the patch. See the list 147 of modules and their :ref:`code owners`. 148 149 - At least one maintainer. See the list of :ref:`maintainers`. 150 151 - If some module has no code owner, try to identify a suitable (non-code 152 owner) reviewer. Running ``git blame`` on the module's source code can 153 help, as it shows who has been working the most recently on this area of 154 the code. 155 156 Alternatively, if it is impractical to identify such a reviewer, you might 157 send an email to the `TF-A mailing list`_ to broadcast your review request 158 to the community. 159 160 Note that self-reviewing a patch is prohibited, even if the patch author is 161 the only code owner of a module modified by the patch. Getting a second pair 162 of eyes on the code is essential to keep up with the quality standards the 163 project aspires to. 164 165- The changes will then undergo further review by the designated people. Any 166 review comments will be made directly on your patch. This may require you to 167 do some rework. For controversial changes, the discussion might be moved to 168 the `TF-A mailing list`_ to involve more of the community. 169 170 Refer to the `Gerrit Uploading Changes documentation`_ for more details. 171 172- The patch submission rules are the following. For a patch to be approved 173 and merged in the tree, it must get: 174 175 - One ``Code-Owner-Review+1`` for each of the modules modified by the patch. 176 - A ``Maintainer-Review+1``. 177 178 In the case where a code owner could not be found for a given module, 179 ``Code-Owner-Review+1`` is substituted by ``Code-Review+1``. 180 181 In addition to these various code review labels, the patch must also get a 182 ``Verified+1``. This is usually set by the Continuous Integration (CI) bot 183 when all automated tests passed on the patch. Sometimes, some of these 184 automated tests may fail for reasons unrelated to the patch. In this case, 185 the maintainers might (after analysis of the failures) override the CI bot 186 score to certify that the patch has been correctly tested. 187 188 In the event where the CI system lacks proper tests for a patch, the patch 189 author or a reviewer might agree to perform additional manual tests 190 in their review and the reviewer incorporates the review of the additional 191 testing in the ``Code-Review+1`` or ``Code-Owner-Review+1`` as applicable to 192 attest that the patch works as expected. Where possible additional tests should 193 be added to the CI system as a follow up task. For example, for a 194 platform-dependent patch where the said platform is not available in the CI 195 system's board farm. 196 197- When the changes are accepted, the :ref:`maintainers` will integrate them. 198 199 - Typically, the :ref:`maintainers` will merge the changes into the 200 ``integration`` branch. 201 202 - If the changes are not based on a sufficiently-recent commit, or if they 203 cannot be automatically rebased, then the :ref:`maintainers` may rebase it 204 on the ``integration`` branch or ask you to do so. 205 206 - After final integration testing, the changes will make their way into the 207 ``master`` branch. If a problem is found during integration, the 208 :ref:`maintainers` will request your help to solve the issue. They may 209 revert your patches and ask you to resubmit a reworked version of them or 210 they may ask you to provide a fix-up patch. 211 212Binary Components 213----------------- 214 215- Platforms may depend on binary components submitted to the `Trusted Firmware 216 binary repository`_ if they require code that the contributor is unable or 217 unwilling to open-source. This should be used as a rare exception. 218- All binary components must follow the contribution guidelines (in particular 219 licensing rules) outlined in the `readme.rst <tf-binaries-readme_>`_ file of 220 the binary repository. 221- Binary components must be restricted to only the specific functionality that 222 cannot be open-sourced and must be linked into a larger open-source platform 223 port. The majority of the platform port must still be implemented in open 224 source. Platform ports that are merely a thin wrapper around a binary 225 component that contains all the actual code will not be accepted. 226- Only platform port code (i.e. in the ``plat/<vendor>`` directory) may rely on 227 binary components. Generic code must always be fully open-source. 228 229-------------- 230 231*Copyright (c) 2013-2020, Arm Limited and Contributors. All rights reserved.* 232 233.. _Conventional Commits: https://www.conventionalcommits.org/en/v1.0.0 234.. _developer.trustedfirmware.org: https://developer.trustedfirmware.org 235.. _review.trustedfirmware.org: https://review.trustedfirmware.org 236.. _issue: https://developer.trustedfirmware.org/project/board/1/ 237.. _Trusted Firmware-A: https://git.trustedfirmware.org/TF-A/trusted-firmware-a.git 238.. _Git guidelines: http://git-scm.com/book/ch5-2.html 239.. _Gerrit Uploading Changes documentation: https://review.trustedfirmware.org/Documentation/user-upload.html 240.. _Gerrit Signed-off-by Lines guidelines: https://review.trustedfirmware.org/Documentation/user-signedoffby.html 241.. _Gerrit Change-Ids documentation: https://review.trustedfirmware.org/Documentation/user-changeid.html 242.. _TF-A Tests: https://trustedfirmware-a-tests.readthedocs.io 243.. _Trusted Firmware binary repository: https://review.trustedfirmware.org/admin/repos/tf-binaries 244.. _tf-binaries-readme: https://git.trustedfirmware.org/tf-binaries.git/tree/readme.rst 245.. _TF-A mailing list: https://lists.trustedfirmware.org/mailman/listinfo/tf-a 246