vfork.s

ucLinux is a very good embeded sytem. Most of company use this as their development OS.

/* vi: set sw=4 ts=4: */
/* vfork for uClibc
 *
 * Copyright (C) 2000 by Lineo, inc. and Erik Andersen
 * Copyright (C) 2000,2001 by Erik Andersen <[e-mail]>
 * Written by Erik Andersen <[e-mail]>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Library General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or (at your
 * option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public License
 * for more details.
 *
 * You should have received a copy of the GNU Library General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

#define _ERRNO_H
#include <bits/errno.h>
#include <sys/syscall.h>

#ifdef __NR_fork
.text
.global vfork
.type vfork,%function
.align 4
vfork:

#ifdef __NR_vfork
	swi	__NR_vfork
	cmn	r0, #4096
	movcc	pc, lr

	/* Check if vfork even exists.  */
	ldr     r1, =-ENOSYS
	teq     r0, r1
	bne     __error
#endif

	/* If we don't have vfork, use fork.  */
	swi     __NR_fork
	cmn     r0, #4096

	/* Syscal worked.  Return to child/parent */
	movcc   pc, lr

__error:
	b	__syscall_error

.size vfork,.-vfork
#endif