arm/sys/fork.S

1.7      matt /*	$NetBSD: fork.S,v 1.7 2013/08/16 22:28:05 matt Exp $	*/
1.1     bjh21
1.1     bjh21 /*-
1.1     bjh21  * Copyright (c) 1990 The Regents of the University of California.
1.1     bjh21  * All rights reserved.
1.1     bjh21  *
1.1     bjh21  * Redistribution and use in source and binary forms, with or without
1.1     bjh21  * modification, are permitted provided that the following conditions
1.1     bjh21  * are met:
1.1     bjh21  * 1. Redistributions of source code must retain the above copyright
1.1     bjh21  *    notice, this list of conditions and the following disclaimer.
1.1     bjh21  * 2. Redistributions in binary form must reproduce the above copyright
1.1     bjh21  *    notice, this list of conditions and the following disclaimer in the
1.1     bjh21  *    documentation and/or other materials provided with the distribution.
1.5       agc  * 3. Neither the name of the University nor the names of its contributors
1.1     bjh21  *    may be used to endorse or promote products derived from this software
1.1     bjh21  *    without specific prior written permission.
1.1     bjh21  *
1.1     bjh21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
1.1     bjh21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
1.1     bjh21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
1.1     bjh21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
1.1     bjh21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
1.1     bjh21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
1.1     bjh21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
1.1     bjh21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
1.1     bjh21  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
1.1     bjh21  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
1.1     bjh21  * SUCH DAMAGE.
1.1     bjh21  *
1.1     bjh21  *	from: @(#)fork.s	5.1 (Berkeley) 4/23/90
1.1     bjh21  */
1.1     bjh21
1.1     bjh21 #include "SYS.h"
1.1     bjh21
1.2     bjh21 /*
1.2     bjh21  * pid = fork();
1.2     bjh21  *
1.2     bjh21  * On return from the SWI:
1.2     bjh21  * r1 == 0 in parent process, r1 == 1 in child process.
1.2     bjh21  * r0 == pid of child in parent, r0 == pid of parent in child.
1.2     bjh21  */
1.2     bjh21
1.3   nathanw _SYSCALL(__fork,fork)
1.7      matt 	subs	r1, r1, #1	/* r1 == 0xffffffff if parent, 0 if child */
1.7      matt 	ands	r0, r0, r1	/* r0 == 0 if child, else unchanged */
1.6  rearnsha 	RET
1.7      matt END(__fork)