1/*	$NetBSD: brk.S,v 1.8 2004/08/21 11:30:17 rearnsha Exp $	*/
2
3/*-
4 * Copyright (c) 1990 The Regents of the University of California.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 *    may be used to endorse or promote products derived from this software
17 *    without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 *
31 *	from: @(#)brk.s	5.2 (Berkeley) 12/17/90
32 */
33
34#include "SYS.h"
35
36	.globl	_C_LABEL(_end)
37	.globl	CURBRK
38
39#ifdef WEAK_ALIAS
40WEAK_ALIAS(brk, _brk)
41#endif
42
43	.data
44	.align	0
45	.globl	_C_LABEL(__minbrk)
46	.type	_C_LABEL(__minbrk),#object
47_C_LABEL(__minbrk):
48	.word	_C_LABEL(_end)
49
50/*
51 * Change the data segment size
52 */
53ENTRY(_brk)
54#ifdef PIC
55	/* Setup the GOT */
56	ldr	r3, .Lgot
57	add	r3, pc, r3
58.L1:
59	ldr	r1, .Lminbrk
60	ldr	r1, [r3, r1]
61#else
62	ldr	r1, .Lminbrk
63#endif
64	/* Get the minimum allowable brk address */
65	ldr	r1, [r1]
66
67	/*
68	 * Valid the address specified and set to the minimum
69	 * if the address is below minbrk.
70	 */
71	cmp	r0, r1
72	movcc	r0, r1
73	mov	r2, r0
74	SYSTRAP(break)
75	bcs	PIC_SYM(CERROR, PLT)
76
77#ifdef PIC
78	ldr	r1, .Lcurbrk
79	ldr	r1, [r3, r1]
80#else
81	ldr	r1, .Lcurbrk
82#endif
83	/* Store the new address in curbrk */
84	str	r2, [r1]
85
86	/* Return 0 for success */
87	mov	r0, #0x00000000
88	RET
89
90	.align	2
91#ifdef PIC
92.Lgot:
93	.word	_C_LABEL(_GLOBAL_OFFSET_TABLE_) + (. - (.L1+4))
94#endif
95.Lminbrk:
96	.word	PIC_SYM(_C_LABEL(__minbrk), GOT)
97.Lcurbrk:
98	.word	PIC_SYM(CURBRK, GOT)
99