Ovfork.S revision 5790 
1/*-
2 * Copyright (c) 1990 The Regents of the University of California.
3 * All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * William Jolitz.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 *    must display the following acknowledgement:
18 *	This product includes software developed by the University of
19 *	California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 *    may be used to endorse or promote products derived from this software
22 *    without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 *
36 *	$Id: Ovfork.S,v 1.1 1994/08/05 01:18:38 wollman Exp $
37 */
38
39#if defined(SYSLIBC_RCS) && !defined(lint)
40	.text
41	.asciz "$Id$"
42#endif /* SYSLIBC_RCS and not lint */
43
44#include "SYS.h"
45
46/*
47 * pid = vfork();
48 *
49 * %edx == 0 in parent process, %edx == 1 in child process.
50 * %eax == pid of child in parent, %eax == pid of parent in child.
51 *
52 */
53	.set	vfork,66
54.globl	_vfork
55.type	_vfork,@function
56
57_vfork:
58	popl	%ecx		/* my rta into ecx */
59	movl	$vfork, %eax
60	LCALL(7,0)
61	jb	verror
62vforkok:
63	cmpl	$0,%edx		/* child process? */
64	jne	child		/* yes */
65	jmp 	parent
66.globl	_errno
67verror:
68#ifdef PIC
69	PIC_PROLOGUE
70	movl	PIC_GOT(_errno), %edx
71	movl	%eax,(%edx)
72	PIC_EPILOGUE
73#else
74	movl	%eax,_errno
75#endif
76	movl	$-1,%eax
77	jmp	%ecx
78child:
79	movl	$0,%eax
80parent:
81	jmp	%ecx
82