proposal: all: add plan9/arm64 port

[psilva261]

Hi!

It would be great to support plan9/arm64. With plan9front it could be used on the MNT Reform and on the Raspberry Pi. The implementation would be similar to plan9/arm.

Also there's a first draft which can already be used. Most tests pass but more work is needed.

Greetings, Philip

[ianlancetaylor]

CC @golang/release

See https://go.dev/wiki/PortingPolicy.

[heschi]

The porting policy says:

The cost must be balanced by an overall benefit in the form of potential new users or use cases for Go.

Is there a significant demand for this?

[psilva261]

On the Plan 9 Mailing Lists a few times people were asking about Go on plan9/arm64 which is also how I found out that a Port wouldn't be that much effort. And of course in general on Plan 9 applications are in demand. At least for a possible builder there was already the offer to find a hosting option.

[DeedleFake]

I ran into this when I was playing around with 9front on a Pi 4 not too long ago. I was quite disappointed. I had a number of things I wanted to experiment with but was unable to because of the lack of support.

[bcmills]

On the one hand, given that plan9 already supports 386, amd64, and arm, the arm64 variant seems like a missing cell in an otherwise-complete matrix.

On the other hand, the existing plan9 ports are already on pretty shaky ground — I count 21 open plan9 issues in the “Test Flakes” project as of right now. (I re-triaged those issues in December to attempt to enable watchflakes monitoring for plan9, but we are currently skipping those builders anyway pending some watchflakes improvements to be able to exclude them from the “broken commit” heuristics.)

So I wonder: would adding arm64 support make cross-arch fixes more likely, or would it contribute yet another set of plan9 failure modes needing triage?