Proposal

I'd like to drop the bare-metal big-endian Armv7-R targets down to Tier 3.

The reason is simple - we cannot test them in https://github.com/rust-embedded/cortex-ar/. This because QEMU support for Big Endian Armv7-R is broken. I tried quite hard, but all the strings I printed with semihosting came out byte swapped (or "etybaws depp") because of how QEMU kludges the access to memory in big-endian mode.

The target also has only a single maintainer. Although, if @chrisnc wants to put up a case for keeping it at Tier 2 though, I'm happy to hear it!

The PR is rust-lang/rust#146523

Process

The main points of the Major Change Process are as follows:

• File an issue describing the proposal.
• A compiler team member who is knowledgeable in the area can second by writing @rustbot second or kickoff a team FCP with @rfcbot fcp $RESOLUTION.
  • Refer to Proposals, Approvals and Stabilization docs for when a second is sufficient, or when a full team FCP is required.
• Once an MCP is seconded, the Final Comment Period begins.
  • Final Comment Period lasts for 10 days after all outstanding concerns are solved.
  • Outstanding concerns will block the Final Comment Period from finishing. Once all concerns are resolved, the 10 day countdown is restarted.
  • If no concerns are raised after 10 days since the resolution of the last outstanding concern, the MCP is considered approved.

You can read more about Major Change Proposals on forge.