Support for LX2

[Frostie314159]

Are there any plans for supporting the LX2 microarch?

[igrr]

I don't think we have a manual for that one. Does it have any software-visible architectural differences compared to other Xtensa implementations? (At least between the LX6 and LX7, I don't think there were any.)

[Frostie314159]

The only thing I have for that arch is, the firmware for the ar9271 nic https://github.com/qca/open-ath9k-htc-firmware I plan on writing a firmware for that nic.

[igrr]

Looking at the config file of that core, I think the only thing that stands out, architecture wise, is that this is a big-endian configuration.

I am not sure there are any assumption about endianness in the xtensa-lx crate or the Xtensa LLVM backend, for that matter. I don't think we've ever worked with a big-endian Xtensa core before, so it is probably something you'll have to try!

If it is of any help, you can add your specific core configuration to the QEMU emulator, likely making the initial development a bit simpler compared to doing it on real hardware.

(The rest of the config looks fairly normal. The core supports XEA2, so at least interrupt handling should work same as on the later Xtensa versions.)

[jessebraham]

We have no plans to support additional architecture at this time. We just finished removing LX106 support for various reasons.

I would suggest forking the repository. If you really feel that support for this arch should be included in this package, you're welcome to open a PR and include a CODEOWNERS file so it's clear who to contact with regards to maintenance.

[Frostie314159]

Thanks for the response, I'm going to close this, since it isn't planned.