1/*	$NetBSD: brk.S,v 1.15 2008/11/06 13:42:55 nakayama Exp $	*/
2
3/*
4 * Copyright (c) 1992, 1993
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * This software was developed by the Computer Systems Engineering group
8 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
9 * contributed to Berkeley.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 *    notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 *    notice, this list of conditions and the following disclaimer in the
18 *    documentation and/or other materials provided with the distribution.
19 * 3. Neither the name of the University nor the names of its contributors
20 *    may be used to endorse or promote products derived from this software
21 *    without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 *
35 * from: Header: brk.s,v 1.3 92/06/25 12:56:05 mccanne Exp
36 */
37
38#include <machine/asm.h>
39#if defined(SYSLIBC_SCCS) && !defined(lint)
40#if 0
41	.asciz "@(#)brk.s	8.1 (Berkeley) 6/4/93"
42#else
43	RCSID("$NetBSD: brk.S,v 1.15 2008/11/06 13:42:55 nakayama Exp $")
44#endif
45#endif /* SYSLIBC_SCCS and not lint */
46
47#include "SYS.h"
48
49	.globl	CURBRK
50	.globl	_C_LABEL(__minbrk)
51	.globl	_end
52
53#ifdef WEAK_ALIAS
54WEAK_ALIAS(brk, _brk)
55#endif
56
57	.data
58_C_LABEL(__minbrk):
59	.long	_end			! lower brk limit; also for gmon code
60	.text
61
62ENTRY(_brk)
63#ifdef __PIC__
64	PIC_PROLOGUE(%o5,%o4)
65	set	_C_LABEL(__minbrk), %o4
66	ld	[%o5 + %o4], %o4
67	ld	[%o4], %o1		! %o1 = minbrk
68	cmp	%o1, %o0		! if (minbrk > %o0)
69	bgu,a	0f
70	 mov	%o1, %o0		!	%o0 = minbrk
710:
72	mov	%o0, %o2		! save argument to syscall
73	mov	SYS_break, %g1
74	t	ST_SYSCALL
75	set	CURBRK, %o3
76	bcc,a	1f
77	 ld	[%o5 + %o3], %o4
78	ERROR()
791:
80	retl				! success, return 0 & record new break
81	 st	%o2, [%o4]
82#else
83	sethi	%hi(_C_LABEL(__minbrk)), %o1	! %o1 = minbrk
84	ld	[%o1 + %lo(_C_LABEL(__minbrk))], %o1
85	cmp	%o1, %o0		! if (minbrk > %o0)
86	bgu,a	0f
87	 mov	%o1, %o0		!	%o0 = minbrk
880:
89	mov	%o0, %o2		! save argument to syscall
90	mov	SYS_break, %g1
91	t	ST_SYSCALL
92	bcc,a	1f
93	 sethi	%hi(CURBRK), %g1
94	ERROR()
951:
96	retl				! success, return 0 & record new break
97	 st	%o2, [%g1 + %lo(CURBRK)]
98#endif
99