sbrk.S revision 1849 
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 *	$Id: sbrk.S,v 1.2 1994/02/21 05:19:16 rgrimes Exp $
37 */
38
39#if defined(SYSLIBC_SCCS) && !defined(lint)
40	.asciz "@(#)sbrk.s	5.1 (Berkeley) 4/23/90"
41#endif /* SYSLIBC_SCCS and not lint */
42
43#include "SYS.h"
44
45#define	SYS_brk		17
46
47	.globl	_end
48	.globl	minbrk
49	.globl	curbrk
50
51	.data
52minbrk:	.long	_end
53curbrk:	.long	_end
54	.text
55
56ENTRY(sbrk)
57#ifdef PIC
58	movl	4(%esp),%ecx
59	PIC_PROLOGUE
60	movl	PIC_GOT(curbrk),%edx
61	movl	(%edx),%eax
62	PIC_EPILOGUE
63	addl	%eax,4(%esp)
64	lea	SYS_brk,%eax
65	LCALL(7,0)
66	jb	err
67	PIC_PROLOGUE
68	movl	PIC_GOT(curbrk),%edx
69	movl	(%edx),%eax
70	addl	%ecx,(%edx)
71	PIC_EPILOGUE
72	ret
73err:
74	jmp	PIC_PLT(cerror)
75
76#else
77
78	movl	4(%esp),%ecx
79	movl	curbrk,%eax
80	addl	%eax,4(%esp)
81	lea	SYS_brk,%eax
82	LCALL(7,0)
83	jb	err
84	movl	curbrk,%eax
85	addl	%ecx,curbrk
86	ret
87err:
88	jmp	cerror
89#endif
90