sbrk.S revision 11183 
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 1995/01/23 01:30:04 davidg Exp $
37 */
38
39#if defined(SYSLIBC_RCS) && !defined(lint)
40	.text
41	.asciz "$Id: sbrk.S,v 1.2 1995/01/23 01:30:04 davidg Exp $"
42#endif /* SYSLIBC_RCS and not lint */
43
44#include "SYS.h"
45
46#define	SYS_brk		17
47
48	.globl	_end
49	.globl	minbrk
50	.globl	curbrk
51
52	.data
53minbrk:	.long	_end
54curbrk:	.long	_end
55	.text
56
57ENTRY(sbrk)
58#ifdef PIC
59	movl	4(%esp),%ecx
60	PIC_PROLOGUE
61	movl	PIC_GOT(curbrk),%edx
62	movl	(%edx),%eax
63	PIC_EPILOGUE
64	testl	%ecx,%ecx
65	jz	back
66	addl	%eax,4(%esp)
67	lea	SYS_brk,%eax
68	LCALL(7,0)
69	jb	err
70	PIC_PROLOGUE
71	movl	PIC_GOT(curbrk),%edx
72	movl	(%edx),%eax
73	addl	%ecx,(%edx)
74	PIC_EPILOGUE
75back:
76	ret
77err:
78	jmp	PIC_PLT(cerror)
79
80#else /* !PIC */
81
82	movl	4(%esp),%ecx
83	movl	curbrk,%eax
84	testl	%ecx,%ecx
85	jz	back
86	addl	%eax,4(%esp)
87	lea	SYS_brk,%eax
88	LCALL(7,0)
89	jb	err
90	movl	curbrk,%eax
91	addl	%ecx,curbrk
92back:
93	ret
94err:
95	jmp	cerror
96#endif /* PIC */
97