1/* $OpenBSD: Ovfork.S,v 1.3 2004/02/16 16:49:58 drahn Exp $ */ 2/* $NetBSD: Ovfork.S,v 1.6 2003/08/07 16:42:03 agc Exp $ */ 3 4/*- 5 * Copyright (c) 1990 The Regents of the University of California. 6 * All rights reserved. 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. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * from: @(#)Ovfork.s 5.1 (Berkeley) 4/23/90 33 */ 34 35#include "SYS.h" 36 37/* 38 * pid = vfork(); 39 * 40 * On return from the SWI: 41 * r1 == 0 in parent process, r1 == 1 in child process. 42 * r0 == pid of child in parent, r0 == pid of parent in child. 43 */ 44 .text 45 .align 0 46 47SYSENTRY(vfork) 48 mov r2, r14 49 SYSTRAP(vfork) 50 bcs PIC_SYM(CERROR, PLT) 51 sub r1, r1, #1 /* r1 == 0xffffffff if parent, 0 if child */ 52 and r0, r0, r1 /* r0 == 0 if child, else unchanged */ 53 mov r15, r2 54