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      1 /*	$NetBSD: __vfork14.S,v 1.2 2003/08/07 16:42:25 agc Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1992, 1993
      5  *	The Regents of the University of California.  All rights reserved.
      6  *
      7  * This software was developed by the Computer Systems Engineering group
      8  * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
      9  * contributed to Berkeley.
     10  *
     11  * Redistribution and use in source and binary forms, with or without
     12  * modification, are permitted provided that the following conditions
     13  * are met:
     14  * 1. Redistributions of source code must retain the above copyright
     15  *    notice, this list of conditions and the following disclaimer.
     16  * 2. Redistributions in binary form must reproduce the above copyright
     17  *    notice, this list of conditions and the following disclaimer in the
     18  *    documentation and/or other materials provided with the distribution.
     19  * 3. Neither the name of the University nor the names of its contributors
     20  *    may be used to endorse or promote products derived from this software
     21  *    without specific prior written permission.
     22  *
     23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     33  * SUCH DAMAGE.
     34  *
     35  * from: Header: Ovfork.s,v 1.1 91/07/06 13:05:56 torek Exp
     36  */
     37 
     38 #include <machine/asm.h>
     39 #if defined(SYSLIBC_SCCS) && !defined(lint)
     40 #if 0
     41 	.asciz "@(#)Ovfork.s	8.1 (Berkeley) 6/4/93"
     42 #else
     43 	RCSID("$NetBSD: __vfork14.S,v 1.2 2003/08/07 16:42:25 agc Exp $")
     44 #endif
     45 #endif /* SYSLIBC_SCCS and not lint */
     46 
     47 /*
     48  * pid = vfork();
     49  *
     50  * %o1 == 0 in parent process, 1 in child process.
     51  * %o0 == pid of child in parent, pid of parent in child.
     52  */
     53 
     54 #include "SYS.h"
     55 
     56 SYSCALL(__vfork14)
     57 	dec	%o1		! from 1 to 0 in child, 0 to -1 in parent
     58 	retl
     59 	and	%o0, %o1, %o0	! return 0 in child, pid in parent
     60