Proposals and RFCs

Many changes, including bug fixes and documentation improvements can be implemented and reviewed via the normal GitHub pull request workflow.

Many changes however are “substantial” and need to go through a design process and produce a consensus among the project stakeholders.

The “RFC” (request for comments) process is intended to provide a consistent and controlled path for new features to enter the project.

Contributors and project stakeholders should consider using this process if they intend to make “substantial” changes to Zephyr or its documentation. Some examples that would benefit from an RFC are:

  • A new feature that creates new API surface area, and would require a feature flag if introduced.

  • The modification of an existing stable API.

  • The removal of features that already shipped as part of Zephyr.

  • The introduction of new idiomatic usage or conventions, even if they do not include code changes to Zephyr itself.

The RFC process is a great opportunity to get more eyeballs on proposals coming from contributors before it becomes a part of Zephyr. Quite often, even proposals that seem “obvious” can be significantly improved once a wider group of interested people have a chance to weigh in.

The RFC process can also be helpful to encourage discussions about a proposed feature as it is being designed, and incorporate important constraints into the design while it’s easier to change, before the design has been fully implemented.

Some changes do not require an RFC:

  • Rephrasing, reorganizing or refactoring

  • Addition or removal of warnings

  • Addition of new boards, SoCs or drivers to existing subsystems

  • …

The process in itself consists in creating a GitHub issue with the RFC label that documents the proposal thoroughly. There is an RFC template included in the main Zephyr GitHub repository that serves as a guideline to write a new RFC.

As with Pull Requests, RFCs might require discussion in the context of one of the Zephyr meetings in order to move it forward in cases where there is either disagreement or not enough voiced opinions in order to proceed. Make sure to either label it appropriately or include it in the corresponding GitHub project in order for it to be examined during the next meeting.