sbrk.S revision 1.13 
1/*	$NetBSD: sbrk.S,v 1.13 2000/06/23 15:40:38 kleink Exp $	*/
2
3/*-
4 * Copyright (c) 1990 The Regents of the University of California.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * William Jolitz.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 * 3. All advertising materials mentioning features or use of this software
19 *    must display the following acknowledgement:
20 *	This product includes software developed by the University of
21 *	California, Berkeley and its contributors.
22 * 4. Neither the name of the University nor the names of its contributors
23 *    may be used to endorse or promote products derived from this software
24 *    without specific prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * SUCH DAMAGE.
37 *
38 *	from: @(#)sbrk.s	5.1 (Berkeley) 4/23/90
39 */
40
41#include <machine/asm.h>
42#if defined(SYSLIBC_SCCS) && !defined(lint)
43	RCSID("$NetBSD: sbrk.S,v 1.13 2000/06/23 15:40:38 kleink Exp $")
44#endif /* SYSLIBC_SCCS and not lint */
45
46#include "SYS.h"
47
48	.globl	_end
49	.globl	CURBRK
50
51	.data
52CURBRK:	.long	_end
53	.text
54
55#ifdef WEAK_ALIAS
56WEAK_ALIAS(sbrk, _sbrk)
57ENTRY(_sbrk)
58#else
59ENTRY(sbrk)
60#endif
61#ifdef PIC
62	movl	4(%esp),%ecx
63	PIC_PROLOGUE
64	movl	PIC_GOT(CURBRK),%edx
65	PIC_EPILOGUE
66	movl	(%edx),%eax
67	addl	%eax,%ecx
68	movl	%ecx,4(%esp)
69	movl	$(SYS_break),%eax
70	int	$0x80
71	jc	err
72	PIC_PROLOGUE
73	movl	PIC_GOT(CURBRK),%edx
74	PIC_EPILOGUE
75	movl	(%edx),%eax
76	movl	%ecx,(%edx)
77	ret
78err:
79	PIC_PROLOGUE
80	mov	PIC_GOT(CERROR),%edx
81	PIC_EPILOGUE
82	jmp	%edx
83#else
84	movl	4(%esp),%ecx
85	movl	CURBRK,%eax
86	addl	%eax,4(%esp)
87	movl	$(SYS_break),%eax
88	int	$0x80
89	jc	err
90	movl	CURBRK,%eax
91	addl	%ecx,CURBRK
92	ret
93err:
94	jmp	CERROR
95#endif
96