cvs commit: src/lib/libc/amd64 SYS.h

Peter Wemm peter at FreeBSD.org
Wed Apr 30 11:06:15 PDT 2003


peter       2003/04/30 11:06:14 PDT

  FreeBSD src repository

  Modified files:
    lib/libc/amd64       SYS.h 
  Log:
  Update for AMD64-style syscalls.  Repocopied from i386/SYS.h.
  Note that the syscall instruction clobbers %rcx, which is inconvenient
  because it is the fourth syscall argument, so we use %r10 (another scratch
  register) for the 4th syscall arg instead (I picked %r10 to be the same as
  NetBSD).  int 0x80 is still possible though, and it uses %rcx as usual.
  Note that the syscall style syscall does *NOT* preserve all the registers,
  unlike int 0x80.  We do not preserve the scratch registers except for
  %rdi and %rsi.  int 0x80 does preserve everything but the return values.
  
  Revision  Changes    Path
  1.25      +4 -7      src/lib/libc/amd64/SYS.h


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