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/* $OpenBSD: Ovfork.S,v 1.4 2009/07/13 21:28:45 miod Exp $ */
/*-
* Copyright (c) 1991, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Ralph Campbell.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include "SYS.h"
/*
* pid = vfork();
*
* v1 == 0 in parent process, v1 == 1 in child process.
* v0 == pid of child in parent, v0 == pid of parent in child.
*/
FRAMESZ= MKFSIZ(1,1)
GPOFF= FRAMESZ-2*REGSZ
SYSLEAF(vfork, FRAMESZ)
PTR_SUBU sp, FRAMESZ
SETUP_GP64(GPOFF, vfork)
.set reorder
li v0, SYS_vfork # system call number for vfork
syscall
beq a3, zero, 1f # jump if no errors
LA t9, cerror
RESTORE_GP64
PTR_ADDU sp, FRAMESZ
jr t9
1:
beq v1, zero, 2f # parent process ?
move v0, zero # return zero in child
2:
RESTORE_GP64
PTR_ADDU sp, FRAMESZ
j ra
SYSEND(vfork)
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