On Wed, 29 Jan 2020 at 16:45, Keith Packard <kei...@keithp.com> wrote: > > Peter Maydell <peter.mayd...@linaro.org> writes: > > > True but irrelevant. You need to refer to a proper > > risc-v specification for your semihosting. > > The RISC-V Foundation defined semihosting as relative to the existing > ARM specification, so using a link to that is appropriate here. > > Here's the current specification of the unprivileged ISA, which includes > the definition of semihosting > > https://riscv.org/specifications/ > > While it may be nice in some abstract sense to create a "better" > semihosting spec, that's not what the RISC-V foundation has decided to > do.
We've gone round this several times. You can't just say "it's the arm spec", because you're not arm and your architecture is different. You need to actually document what the architecture-specific parts are, even if you want to mostly say "and we follow the Arm spec most of the time". If you really really want to say "32 bit RISC-V is gratuitously different from 64-bit RISC-V in these areas because we just blindly copied the way Arm happened to have historically developed" then you can do that if you like, but you need to actually write it down in a document somewhere. You're trying to implement an ABI which has multiple different implementations of both consumers and producers; it's not a good idea to shortcut the process of actually writing down what the requirements between the two ends are. thanks -- PMM
