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fork.S revision 1.10
      1  1.10      uwe /*	$NetBSD: fork.S,v 1.10 2006/01/06 05:11:29 uwe Exp $	*/
      2   1.1  msaitoh 
      3   1.1  msaitoh /*-
      4   1.1  msaitoh  * Copyright (c) 1990 The Regents of the University of California.
      5   1.1  msaitoh  * All rights reserved.
      6   1.1  msaitoh  *
      7   1.1  msaitoh  * This code is derived from software contributed to Berkeley by
      8   1.1  msaitoh  * William Jolitz.
      9   1.1  msaitoh  *
     10   1.1  msaitoh  * Redistribution and use in source and binary forms, with or without
     11   1.1  msaitoh  * modification, are permitted provided that the following conditions
     12   1.1  msaitoh  * are met:
     13   1.1  msaitoh  * 1. Redistributions of source code must retain the above copyright
     14   1.1  msaitoh  *    notice, this list of conditions and the following disclaimer.
     15   1.1  msaitoh  * 2. Redistributions in binary form must reproduce the above copyright
     16   1.1  msaitoh  *    notice, this list of conditions and the following disclaimer in the
     17   1.1  msaitoh  *    documentation and/or other materials provided with the distribution.
     18   1.8      agc  * 3. Neither the name of the University nor the names of its contributors
     19   1.1  msaitoh  *    may be used to endorse or promote products derived from this software
     20   1.1  msaitoh  *    without specific prior written permission.
     21   1.1  msaitoh  *
     22   1.1  msaitoh  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     23   1.1  msaitoh  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     24   1.1  msaitoh  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     25   1.1  msaitoh  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     26   1.1  msaitoh  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     27   1.1  msaitoh  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     28   1.1  msaitoh  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     29   1.1  msaitoh  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     30   1.1  msaitoh  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     31   1.1  msaitoh  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     32   1.1  msaitoh  * SUCH DAMAGE.
     33   1.1  msaitoh  *
     34   1.1  msaitoh  *	from: @(#)fork.s	5.1 (Berkeley) 4/23/90
     35   1.1  msaitoh  */
     36   1.1  msaitoh 
     37   1.1  msaitoh #include <machine/asm.h>
     38   1.1  msaitoh #if defined(SYSLIBC_SCCS) && !defined(lint)
     39  1.10      uwe 	RCSID("$NetBSD: fork.S,v 1.10 2006/01/06 05:11:29 uwe Exp $")
     40   1.1  msaitoh #endif /* SYSLIBC_SCCS and not lint */
     41   1.1  msaitoh 
     42   1.1  msaitoh #include "SYS.h"
     43   1.1  msaitoh 
     44  1.10      uwe /*
     45  1.10      uwe  * pid = fork();
     46  1.10      uwe  *
     47  1.10      uwe  * r1 == 0 in parent process, r1 == 1 in child process.
     48  1.10      uwe  * r0 == pid of child in parent, r0 == pid of parent in child.
     49  1.10      uwe  *
     50  1.10      uwe  */
     51  1.10      uwe ENTRY(__fork)
     52  1.10      uwe 	mov	#SYS_fork, r0
     53  1.10      uwe 	trapa	#0x80
     54  1.10      uwe 	bf	err
     55   1.9      uwe 
     56  1.10      uwe 	add	#0xff, r1	/* from 1 to 0 in child, 0 to -1 in parent */
     57  1.10      uwe 	rts
     58  1.10      uwe 	 and	r1, r0		/* 0 in child, child pid in parent */
     59  1.10      uwe 
     60  1.10      uwe err:
     61  1.10      uwe 	JUMP_CERROR
     62   1.9      uwe 
     63  1.10      uwe 	SET_ENTRY_SIZE(__fork)
     64