On Tue, 1 Aug 2023 at 16:28, Keith Packard <kei...@keithp.com> wrote: > > > > Yeah, the closest to a "standard" we have for nios2 is that > > I asked the Codesourcery folks to document it in the libgloss > > sources and put the URL to it in a comment at the top of > > nios2-semi.c, given that there's no official spec and the > > original and main guest-side user is libgloss. > > m68k is in a similar position only without the URL > > in our source file :-) > > Yeah, we had the same ask when getting risc-v semihosting merged. For > that, I actually pushed through an "official" risc-v standard. I kinda > wish I'd used the m68k model instead of the arm model as that provides > simple POSIX semantics...
Yeah, there's a lot of stuff in the Arm semihosting API that I wouldn't put in there for a from-new version that didn't need to handle legacy guests. Notably the "errno" concept is badly underspecified and/or broken. On an architecture with a decent number of registers it would probably also make sense to use them rather than having every single call put its args in memory. thanks -- PMM
