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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