syscall-alt

[syscall-alt] is a rust crate that provides inline assembler (asm! macro) definitions of syscalls for some Linux platforms. It also includes:-

• An enum defining common Linux syscalls;
• Some minor wrapper logic to make straightforward to work with syscalls.
• Correct Syscall / Posix error codes ('E'), eg EINVAL
  • Linux:-
    • These differ slightly on MIPS and PowerPC
    • MIPS64 is the same as MIPS
    • PowerPC64 is the same as PowerPC
    • PowerPC is nearly identical to x8664 bar EDEADLOCK:-
      • PowerPC is the only platform on which EDEADLOCK != EDEADLK (so watch out when using match)
    • MIPS is very different to x8664
      • But it has exactly the same set of E numbers
• SYS call numbers and E numbers are available for every arch, eg if you want to know them for arm, but are compiled for x86_64, they are available
  • Watch out if using EDEADLOCK, EDEADLCK, ENOTSUP and EOPNOTSUPP; these vary in definition and value, sometimes being missing, sometimes being equal
  • Take a little care with EWOULDBLOCK and EAGAIN; all current platforms make EWOULDBLOCK the same as EAGAIN, but this isn't required by POSIX
• A windows stub, which contains EAGAIN, etc, as defined on Windows (but no syscall numbers)

The code is very much 'early-days', so expect breaking changes.

This crate is #[!no_std], and does not require the std library or the libc crate

TODO

• syscalls are not actually implemented for Linux mips, mips64, powerpc, powerpc64, or s390x but could be by tring to use musl's syscall_arch.h headers (bar s390x)
• We could implement iOS ARM 32-bit syscalls; see https://stackoverflow.com/questions/4371897/arm-darwin-assembly-looking-for-system-calls-tutorial-perhaps for ideas
• Support ARM and ARM64 for the BSDs as and when rust gains support for them
• Syscalling is not implemented for Solaris, and won't ever be implemented for Windows

Licensing

The license for this project is AGPL.