1/*	$NetBSD: Ovfork.S,v 1.4 2003/08/07 16:42:29 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: Ovfork.S,v 1.4 2003/08/07 16:42:29 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
56WARN_REFERENCES(vfork, \
57    "warning: reference to compatibility vfork(); include <unistd.h> for correct reference")
58
59SYSCALL(vfork)
60	dec	%o1		/* from 1 to 0 in child, 0 to -1 in parent */
61	retl
62	 and	%o0, %o1, %o0	/* return 0 in child, pid in parent */
63