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/* Copyright (C) 1991, 1992, 1993, 1994, 1995 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If
not, write to the Free Software Foundation, Inc., 675 Mass Ave,
Cambridge, MA 02139, USA. */
#include <sysdep.h>
#ifndef SYS_vfork
#define SYS_vfork 66
#endif
/* Clone the calling process, but without copying the whole address space.
The the calling process is suspended until the the new process exits or is
replaced by a call to `execve'. Return -1 for errors, 0 to the new process,
and the process ID of the new process to the old process. */
.globl ___vfork
___vfork:
/* Pop the return PC value into A0. */
movel sp@+, a0
/* Push the syscall number and trap into the kernel. */
movel #SYS_vfork, sp@-
trap #0
bcs error /* Branch forward if it failed. */
/* It succeeded. See which fork we're in. D1 is now 0 for the
parent and 1 for the child. Decrement it to make it -1 (all
bits set) for the parent, and 0 (no bits set) for the child.
Then AND it with D0, so the parent gets D0&-1==R0, and the child
gets D0&0==0. */
subql #1, d1
andl d1, d0
/* Jump to the return PC. */
jmp a0@
error:
movel d0, _errno
moveq #-1, d0
jmp a0@
weak_alias (__vfork, vfork)
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