xref: /original-bsd/lib/libc/i386/sys/Ovfork.s (revision c3e32dec)
1/*-
2 * Copyright (c) 1990, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * William Jolitz.
7 *
8 * %sccs.include.redist.c%
9 */
10
11#if defined(SYSLIBC_SCCS) && !defined(lint)
12	.asciz "@(#)Ovfork.s	8.1 (Berkeley) 06/04/93"
13#endif /* SYSLIBC_SCCS and not lint */
14
15#include "SYS.h"
16
17/*
18 * pid = vfork();
19 *
20 * %edx == 0 in parent process, %edx == 1 in child process.
21 * %eax == pid of child in parent, %eax == pid of parent in child.
22 *
23 */
24	.set	vfork,66
25.globl	_vfork
26
27_vfork:
28	popl	%ecx		/* my rta into ecx */
29	movl	$vfork, %eax
30	LCALL(7,0)
31	jb	verror
32vforkok:
33	cmpl	$0,%edx		/* child process? */
34	jne	child		/* yes */
35	jmp 	parent
36.globl	_errno
37verror:
38	movl	%eax,_errno
39	movl	$-1,%eax
40	jmp	%ecx
41child:
42	movl	$0,%eax
43parent:
44	jmp	%ecx
45