sbrk.S revision 1.2 
1/*-
2 * Copyright (c) 1990 The Regents of the University of California.
3 * All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * William Jolitz.
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. All advertising materials mentioning features or use of this software
17 *    must display the following acknowledgement:
18 *	This product includes software developed by the University of
19 *	California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 *    may be used to endorse or promote products derived from this software
22 *    without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 *
36 *	from: @(#)sbrk.s	5.1 (Berkeley) 4/23/90
37 *	$Id: sbrk.S,v 1.2 1993/10/21 02:19:36 jtc Exp $
38 */
39
40#if defined(SYSLIBC_SCCS) && !defined(lint)
41	.text
42	.asciz "$Id: sbrk.S,v 1.2 1993/10/21 02:19:36 jtc Exp $"
43#endif /* SYSLIBC_SCCS and not lint */
44
45#include "SYS.h"
46
47#define	SYS_brk		17
48
49	.globl	_end
50	.globl	minbrk
51	.globl	curbrk
52
53	.data
54minbrk:	.long	_end
55curbrk:	.long	_end
56	.text
57
58ENTRY(sbrk)
59#ifdef PIC
60	movl	4(%esp),%ecx
61	PIC_PROLOGUE
62	movl	PIC_GOT(curbrk),%edx
63	movl	(%edx),%eax
64	PIC_EPILOGUE
65	addl	%eax,4(%esp)
66	lea	SYS_brk,%eax
67	LCALL(7,0)
68	jb	err
69	PIC_PROLOGUE
70	movl	PIC_GOT(curbrk),%edx
71	movl	(%edx),%eax
72	addl	%ecx,(%edx)
73	PIC_EPILOGUE
74	ret
75err:
76	jmp	PIC_PLT(cerror)
77
78#else
79
80	movl	4(%esp),%ecx
81	movl	curbrk,%eax
82	addl	%eax,4(%esp)
83	lea	SYS_brk,%eax
84	LCALL(7,0)
85	jb	err
86	movl	curbrk,%eax
87	addl	%ecx,curbrk
88	ret
89err:
90	jmp	cerror
91#endif
92