add support for rve - Githubissues

riscv-software-src / riscv-pk

RISC-V Proxy Kernel

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add support for rve #280

Open liweiwei90 opened 2 years ago

liweiwei90 commented 2 years ago

This PR adds support for rve, if rve is enabled:

disable the handling of upper registers
change the syscall number to register t0

aswaterman commented 2 years ago

Is there an RVE ABI that specifies the syscall number comes in t0? It is a reasonable choice, but I want to make sure it is written down somewhere before adding software support for it.

liweiwei90 commented 2 years ago

Sorry for late reply. I didn't find any spec to write this. I just found this in a closed issue(https://github.com/riscv-non-isa/riscv-elf-psabi-doc/issues/11).

Is there an RVE ABI that specifies the syscall number comes in t0? It is a reasonable choice, but I want to make sure it is written down somewhere before adding software support for it.

aswaterman commented 2 years ago

OK, I propose we leave this PR open until there is a written RV32E syscall ABI.

liweiwei90 commented 2 years ago

OK, I propose we leave this PR open until there is a written RV32E syscall ABI.

OK.