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compat_Ovfork.S revision 1.1.10.1 
      1 /*	$NetBSD: compat_Ovfork.S,v 1.1.10.1 2007/11/06 18:39:11 matt Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1990 The Regents of the University of California.
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. Neither the name of the University nor the names of its contributors
     16  *    may be used to endorse or promote products derived from this software
     17  *    without specific prior written permission.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     29  * SUCH DAMAGE.
     30  *
     31  *	from: @(#)Ovfork.s	5.1 (Berkeley) 4/23/90
     32  */
     33 
     34 #include "SYS.h"
     35 
     36 WARN_REFERENCES(vfork, \
     37     "warning: reference to compatibility vfork(); include <unistd.h> for correct reference")
     38 
     39 /*
     40  * pid = vfork();
     41  *
     42  * On return from the SWI:
     43  * r1 == 0 in parent process, r1 == 1 in child process.
     44  * r0 == pid of child in parent, r0 == pid of parent in child.
     45  */
     46 	.text
     47 	.align	0
     48 
     49 ENTRY(vfork)
     50 	mov	r2, lr
     51 	SYSTRAP(vfork)
     52 	_SYSCALL_CERROR_CHECK
     53 	mov	lr, r2
     54 	sub	r1, r1, #1	/* r1 == 0xffffffff if parent, 0 if child */
     55 	and	r0, r0, r1	/* r0 == 0 if child, else unchanged */
     56 	RET
     57