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