xref: /netbsd/lib/libc/arch/m68k/sys/brk.S (revision bf9ec67e)
1/*	$NetBSD: brk.S,v 1.13 2001/05/05 17:46:37 kleink Exp $	*/
2
3/*-
4 * Copyright (c) 1990 The Regents of the University of California.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * the Systems Programming Group of the University of Utah Computer
9 * Science Department.
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. All advertising materials mentioning features or use of this software
20 *    must display the following acknowledgement:
21 *	This product includes software developed by the University of
22 *	California, Berkeley and its contributors.
23 * 4. Neither the name of the University nor the names of its contributors
24 *    may be used to endorse or promote products derived from this software
25 *    without specific prior written permission.
26 *
27 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
30 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
37 * SUCH DAMAGE.
38 */
39
40#include "SYS.h"
41
42#if defined(LIBC_SCCS) && !defined(lint)
43#if 0
44	RCSID("from: @(#)brk.s	5.1 (Berkeley) 5/12/90")
45#else
46	RCSID("$NetBSD: brk.S,v 1.13 2001/05/05 17:46:37 kleink Exp $")
47#endif
48#endif /* LIBC_SCCS and not lint */
49
50	.globl	_end
51	.globl	_C_LABEL(__minbrk)
52	.globl	CURBRK
53
54#ifdef WEAK_ALIAS
55WEAK_ALIAS(brk, _brk)
56#endif
57
58	.data
59_C_LABEL(__minbrk):
60	.long	_end
61
62	.text
63
64ENTRY(_brk)
65#ifdef	PIC
66#ifdef	__ELF__
67	lea	%pc@(_GLOBAL_OFFSET_TABLE_@GOTPC),%a1
68	movl	%a1@(_C_LABEL(__minbrk)@GOT:w),%a0
69#else
70	movl	#_C_LABEL(_GLOBAL_OFFSET_TABLE_),%a1
71	lea	%pc@(0,a1:l),%a1
72	movl	%a1@(_C_LABEL(__minbrk):w),%a0
73#endif
74	movl	%a0@,%d0
75#else
76	movl	_C_LABEL(__minbrk),%d0
77#endif
78	cmpl	%sp@(4),%d0
79	jle	ok
80	movl	%d0,%sp@(4)
81ok:
82	movl	#SYS_break,%d0
83	trap	#0
84	jcs	err
85#ifdef	PIC
86#ifdef	__ELF__
87	movl	%a1@(CURBRK@GOT:w),%a0
88#else
89	movl	%a1@(CURBRK:w),%a0
90#endif
91	movl	%sp@(4),%a0@
92#else
93	movl	%sp@(4),CURBRK
94#endif
95	clrl	%d0
96	rts
97err:
98	jra	PIC_PLT(CERROR)
99