1/* 2 * Copyright (c) 1992 The Regents of the University of California. 3 * All rights reserved. 4 * 5 * This software was developed by the Computer Systems Engineering group 6 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and 7 * contributed to Berkeley. 8 * 9 * %sccs.include.redist.c% 10 * 11 * from: $Header: Ovfork.s,v 1.1 91/07/06 13:05:56 torek Exp $ 12 */ 13 14#if defined(LIBC_SCCS) && !defined(lint) 15 .asciz "@(#)Ovfork.s 5.1 (Berkeley) 06/25/92" 16#endif /* LIBC_SCCS and not lint */ 17 18/* 19 * pid = vfork(); 20 * 21 * %o1 == 0 in parent process, 1 in child process. 22 * %o0 == pid of child in parent, pid of parent in child. 23 */ 24 25#include "SYS.h" 26 27SYSCALL(vfork) 28 dec %o1 ! from 1 to 0 in child, 0 to -1 in parent 29 retl 30 and %o0, %o1, %o0 ! return 0 in child, pid in parent 31