TSC Project Roles
TSC projects generally will involve Maintainers, Collaborators, and Contributors:
Maintainer: lead Collaborators on an area identified by the TSC (e.g. Architecture, code subsystems, etc.). Maintainers shall also serve as the area’s representative on the TSC as needed. Maintainers may become voting members of the TSC under the guidelines stated in the project Charter.
Collaborator: A highly involved Contributor in one or more areas. May become a Maintainer with approval of existing TSC voting members.
Contributor: anyone in the community that contributes code or documentation to the project. Contributors may become Collaborators by approval of the existing Collaborators and Maintainers of the particular code base areas or subsystems.
A Contributor is a developer who wishes to contribute to the project, at any level.
Contributors are granted the following rights and responsibilities:
Right to contribute code, documentation, translations, artwork, etc.
Right to report defects (bugs) and suggestions for enhancement.
Right to participate in the process of reviewing contributions by others.
Right to initiate and participate in discussions in any communication methods.
Right to approach any member of the community with matters they believe to be important.
Right to participate in the feature development process.
Responsibility to abide by decisions, once made. They are welcome to provide new, relevant information to reopen decisions.
Responsibility for issues and bugs introduced by one’s own contributions.
Responsibility to respect the rules of the community.
Responsibility to provide constructive advice whenever participating in discussions and in the review of contributions.
Responsibility to follow the project’s code of conduct (https://github.com/zephyrproject-rtos/zephyr/blob/main/CODE_OF_CONDUCT.md)
Contributors are initially only given Read access to the Zephyr GitHub repository. Specifically, at the Read access level, Contributors are not allowed to assign reviewers to their own pull requests. An automated process will assign reviewers. You may also share the pull request on the Zephyr devel mailing list or on the Zephyr Discord Server.
Contributors who show dedication and skill are granted the Triage permission level to the Zephyr GitHub repository.
You may nominate yourself, or another GitHub user, for promotion to the Triage permission level by creating a GitHub issue, using the nomination template.
Contributors granted the Triage permission level are permitted to add reviewers to a pull request and can be added as a reviewer by other GitHub users. Contributor change requests or approval on pull requests are not counted with respect to accepting and merging a pull request. However, Contributors comments and requested changes should still be considered by the pull request author.
A Collaborator is a Contributor who is also responsible for the maintenance of Zephyr source code. Their opinions weigh more when decisions are made, in a fully meritocratic fashion.
Collaborators have the following rights and responsibilities, in addition to those listed for Contributors:
Right to set goals for the short and medium terms for the project being maintained, alongside the Maintainer.
Responsibility to participate in the feature development process.
Responsibility to review relevant code changes within reasonable time.
Responsibility to ensure the quality of the code to expected levels.
Responsibility to participate in community discussions.
Responsibility to mentor new contributors when appropriate
Responsibility to participate in the quality verification and release process, when those happen.
Contributors are promoted to the Collaborator role by adding the GitHub user
name to one or more
collaborators sections of the MAINTAINERS File in
the Zephyr repository.
Collaborator change requests on pull requests should be addressed by the original submitter. In cases where the changes requested do not follow the expectations and the guidelines of the project or in cases of disagreement, it is the responsibility of the assignee to advance the review process and resolve any disagreements.
Collaborator approval of pull requests are counted toward the minimum required approvals needed to merge a PR. Other criteria for merging may apply.
A Maintainer is a Collaborator who is also responsible for knowing, directing and anticipating the needs of a given zephyr source code area.
Maintainers have the following rights and responsibilities, in addition to those listed for Contributors and Collaborators:
Right to set the overall architecture of the relevant subsystems or areas of involvement.
Right to make decisions in the relevant subsystems or areas of involvement, in conjunction with the collaborators and submitters. See PR Technical Escalation.
Responsibility to convey the direction of the relevant subsystem or areas to the TSC
Responsibility to ensure all contributions of the project have been reviewed within reasonable time.
Responsibility to enforce the code of conduct.
Contributors or Collaborators are promoted to the Maintainer role by adding the
GitHub user name to one or more
maintainers sections of the
MAINTAINERS File in the Zephyr repository.
Maintainer approval of pull requests are counted toward the minimum required approvals needed to merge a PR. Other criteria for merging may apply.
Individuals elected to the following Project roles, including, Maintainer, Release Engineering Team member, Release Manager, but are no longer engaged in the project as described by the rights and responsibilities of that role, may be requested by the TSC to retire from the role they are elected.
Such a request needs to be raised as a motion in the TSC and be approved by the TSC voting members. By approval of the TSC the individual is considered to be retired from the role they have been elected.
The above applies to elected TSC Project roles that may be defined in addition.
Teams and Supporting Activities
An Assignee is one of the maintainers of a subsystem or code being changed. Assignees are set either automatically based on the code being changed or set by the other Maintainers, the Release Engineering team can set an assignee when the latter is not possible.
Right to dismiss stale and unrelated reviews or reviews not following expectations from reviewers and seek reviews from additional maintainers, developers and contributors
Right to block pull requests from being merged until issues or changes requested are addressed
Responsibility to re-assign a pull request if they are the original submitter of the code
Responsibility to drive the pull request to a mergeable state
Solicit approvals from maintainers of the subsystems affected
Responsibility to drive the PR Technical Escalation process
Release Engineering Team
A team of active Maintainers involved in multiple areas.
The members of the Release Engineering team are expected to fill the Release Manager role based on a defined cadence and selection process.
The cadence and selection process are defined by the Release Engineering team and are approved by the TSC.
The team reports directly into the TSC.
Release Engineering team has the following rights and responsibilities:
Right to merge code changes to the zephyr tree following the project rules.
Right to revert any changes that have broken the code base
Right to close any stale changes after <N> months of no activity
Responsibility to take directions from the TSC and follow them.
Responsibility to coordinate code merges with maintainers.
Responsibility to merge all contributions regardless of their origin and area if they have been approved by the respective maintainers and follow the merge criteria of a change.
Responsibility to keep the Zephyr code base in a working and passing state (as per CI)
Joining the Release Engineering team
Maintainers highly involved in the project may be nominated by a TSC voting member to join the Release Engineering team. Nominees may become members of the team by approval of the existing TSC voting members.
To ensure a functional Release Engineering team the TSC shall periodically review the team’s followed processes, the appropriate size, and the membership composition (ensure, for example, that team members are geographically distributed across multiple locations and time-zones).
A Maintainer responsible for driving a specific release to completion following the milestones and the roadmap of the project for this specific release.
TSC has to approve a release manager.
A Release Manager is a member of the Release Engineering team and has the rights and responsibilities of that team in addition to the following:
Right to manage and coordinate all code merges after the code freeze milestone (M3, see program management overview.)
Responsibility to drive and coordinate the triaging process for the release
Responsibility to create the release notes of the release
Responsibility to notify all stakeholders of the project, including the community at large about the status of the release in a timely manner.
Responsibility to coordinate with QA and validation and verify changes either directly or through QA before major changes and major milestones.
Roles / Permissions
Generic guidelines for deciding and filling in the Maintainers’ list
We should keep the granularity of code maintainership at a manageable level
We should be looking for maintainers for areas of code that are orphaned (i.e. without an explicit maintainer)
Un-maintained areas should be indicated clearly in the MAINTAINERS file
All submitted pull requests should have an assignee
We Introduce an area/subsystem hierarchy to address the above point
Parent-area maintainer should be acting as default substitute/fallback assignee for un-maintained sub-areas
Area maintainer gets precedence over parent-area maintainer
Pull requests may be re-assigned if this is needed or more appropriate
Re-assigned by original assignee
In general, updates to the MAINTAINERS file should be in a standalone commit alongside other changes introducing new files and directories to the tree.
Major changes to the file, including the addition of new areas with new maintainers should come in as standalone pull requests and require TSC review.
If additional review by the TSC is required, the maintainers of the file should send the requested changes to the TSC and give members of the TSC two (2) days to object to any of the changes to maintainership of areas or the addition of new maintainers or areas.
Path, collaborator and name changes do not require a review by the TSC.
Addition of new areas without a maintainer do not require review by the TSC.
The MAINTAINERS file itself shall have a maintainer
Architectures, core components, sub-systems, samples, tests
Each area shall have an explicit maintainer
Boards (incl relevant samples, tests), SoCs (incl DTS) * May have a maintainer, shall have a higher-level platform maintainer
Shall have a driver-area (and API) maintainer
Could have individual driver implementation maintainers but preferably collaborator/contributors
In the above case, platform-specific PRs may be re-assigned to respective collaborator/contributor of driver implementation
Minimal of 2 approvals, including an approval by the designated assignee.
Pull requests should be reviewed by at least a maintainer or collaborator of each affected area; Unless the changes to a given area are considered trivial enough, in which case approvals by other affected subsystems maintainers/collaborators would suffice.
Four eye principle on the organisation level. We already require at least 2 approvals (basic four eye principle), however, such reviews and approvals might be unintentionally biased in the case where the submitter is from the same organisation as the approvers. To allow for project wide review and approvals, the merge criteria is extended with the guidelines below:
Changes or additions to common and shared code shall have approvals from different organisations (at least one approval from an organisation different than the submitters’). Common and shared code is defined as anything that does not fall under
Changes or additions to hardware support (driver, SoC, boards) shall at least have the merger be from a different organisation. This applies only to implementation of an API supporting vendor specific hardware and not the APIs.
Release engineers may make exceptions for areas with contributions primarily coming from one organisation and where reviews from other organisations are not possible, however, merges shall be completed by a person from a different organisation. In such cases, the minimum review period of at least 2 days shall be strictly followed to allow for additional reviews.
Release engineers shall not merge code changes originating and reviewed only by their own organisation. To be able to merge such changes, at least one review shall be from a different organisation.
A minimum review period of 2 business days, 4 hours for trivial changes (see Give reviewers time to review before code merge).
Hotfixes can be merged at any time after CI has passed and are excluded from most of the conditions listed above.
All required checks are passing:
Checkpatch (Coding Style)
Integration Tests (Via twister) on emulation/simulation platforms
Simulated Bluetooth Tests
Static Analysis (Coverity)
Documentation coverage (APIs)