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__vfork14.S revision 1.3
      1  1.3   kleink /*	$NetBSD: __vfork14.S,v 1.3 1998/10/06 19:05:26 kleink Exp $	*/
      2  1.1  thorpej 
      3  1.1  thorpej /*-
      4  1.1  thorpej  * Copyright (c) 1990 The Regents of the University of California.
      5  1.1  thorpej  * All rights reserved.
      6  1.1  thorpej  *
      7  1.1  thorpej  * This code is derived from software contributed to Berkeley by
      8  1.1  thorpej  * the Systems Programming Group of the University of Utah Computer
      9  1.1  thorpej  * Science Department.
     10  1.1  thorpej  *
     11  1.1  thorpej  * Redistribution and use in source and binary forms, with or without
     12  1.1  thorpej  * modification, are permitted provided that the following conditions
     13  1.1  thorpej  * are met:
     14  1.1  thorpej  * 1. Redistributions of source code must retain the above copyright
     15  1.1  thorpej  *    notice, this list of conditions and the following disclaimer.
     16  1.1  thorpej  * 2. Redistributions in binary form must reproduce the above copyright
     17  1.1  thorpej  *    notice, this list of conditions and the following disclaimer in the
     18  1.1  thorpej  *    documentation and/or other materials provided with the distribution.
     19  1.1  thorpej  * 3. All advertising materials mentioning features or use of this software
     20  1.1  thorpej  *    must display the following acknowledgement:
     21  1.1  thorpej  *	This product includes software developed by the University of
     22  1.1  thorpej  *	California, Berkeley and its contributors.
     23  1.1  thorpej  * 4. Neither the name of the University nor the names of its contributors
     24  1.1  thorpej  *    may be used to endorse or promote products derived from this software
     25  1.1  thorpej  *    without specific prior written permission.
     26  1.1  thorpej  *
     27  1.1  thorpej  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     28  1.1  thorpej  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     29  1.1  thorpej  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     30  1.1  thorpej  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     31  1.1  thorpej  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     32  1.1  thorpej  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     33  1.1  thorpej  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     34  1.1  thorpej  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     35  1.1  thorpej  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     36  1.1  thorpej  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     37  1.1  thorpej  * SUCH DAMAGE.
     38  1.1  thorpej  */
     39  1.1  thorpej 
     40  1.1  thorpej #include "SYS.h"
     41  1.1  thorpej 
     42  1.1  thorpej #if defined(LIBC_SCCS) && !defined(lint)
     43  1.1  thorpej #if 0
     44  1.1  thorpej 	RCSID("from: @(#)Ovfork.s	5.1 (Berkeley) 5/12/90")
     45  1.1  thorpej #else
     46  1.3   kleink 	RCSID("$NetBSD: __vfork14.S,v 1.3 1998/10/06 19:05:26 kleink Exp $")
     47  1.1  thorpej #endif
     48  1.1  thorpej #endif /* LIBC_SCCS and not lint */
     49  1.1  thorpej 
     50  1.1  thorpej /*
     51  1.1  thorpej  * @(#)vfork.s	4.1 (Berkeley) 12/21/80
     52  1.1  thorpej  * C library -- vfork
     53  1.1  thorpej  */
     54  1.1  thorpej 
     55  1.1  thorpej /*
     56  1.1  thorpej  * pid = vfork();
     57  1.1  thorpej  *
     58  1.1  thorpej  * d1 == 0 in parent process, d1 == 1 in child process.
     59  1.1  thorpej  * d0 == pid of child in parent, d0 == pid of parent in child.
     60  1.1  thorpej  *
     61  1.1  thorpej  * trickery here, due to keith sklower, uses ret to clear the stack,
     62  1.1  thorpej  * and then returns with a jump indirect, since only one person can return
     63  1.1  thorpej  * with a ret off this stack... we do the ret before we vfork!
     64  1.1  thorpej  */
     65  1.1  thorpej 
     66  1.1  thorpej ENTRY(__vfork14)
     67  1.1  thorpej 	movl	sp@+,a0
     68  1.1  thorpej 	movl	#SYS___vfork14,d0
     69  1.1  thorpej 	trap	#0
     70  1.1  thorpej 	jcs	err
     71  1.1  thorpej 	subql	#1,d1	/* from 1 to 0 in child, 0 to -1 in parent */
     72  1.1  thorpej 	andl	d1,d0
     73  1.1  thorpej 	jmp	a0@
     74  1.1  thorpej err:
     75  1.3   kleink #ifdef	_REENTRANT
     76  1.3   kleink 	.globl	_C_LABEL(__errno)
     77  1.3   kleink 	movl	a0,sp@-
     78  1.3   kleink 	movl	d0,sp@-
     79  1.3   kleink #ifdef	PIC
     80  1.3   kleink 	movl	#_C_LABEL(_GLOBAL_OFFSET_TABLE_),a1
     81  1.3   kleink 	lea	pc@(0,a1:l),a1
     82  1.3   kleink 	movl	a1@(_C_LABEL(__errno):l),a1
     83  1.3   kleink 	jsr	a1@
     84  1.3   kleink #else
     85  1.3   kleink 	jbsr	_C_LABEL(__errno)
     86  1.3   kleink #endif	/* PIC */
     87  1.3   kleink 	movl	d0,a1
     88  1.3   kleink 	movl	sp@+,a1@
     89  1.3   kleink 	movl	sp@+,a0
     90  1.3   kleink #else
     91  1.2  thorpej 	.globl	_C_LABEL(errno)
     92  1.1  thorpej #ifdef	PIC
     93  1.3   kleink 	movl	#_C_LABEL(_GLOBAL_OFFSET_TABLE_),a1
     94  1.1  thorpej 	lea	pc@(0,a1:l),a1
     95  1.2  thorpej 	movl	a1@(_C_LABEL(errno):w),a1
     96  1.1  thorpej 	movl	d0,a1@
     97  1.1  thorpej #else
     98  1.2  thorpej 	movl	d0,_C_LABEL(errno)
     99  1.3   kleink #endif	/* PIC */
    100  1.3   kleink #endif	/* _REENTRANT */
    101  1.1  thorpej 	moveq	#-1,d0
    102  1.1  thorpej 	jmp	a0@
    103