xref: /minix/lib/libc/arch/riscv/sys/brk.S (revision 0a6a1f1d)
1/*	$NetBSD: brk.S,v 1.4 2015/03/31 11:59:41 matt Exp $	*/
2
3/*-
4 * Copyright (c) 2014 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Matt Thomas of 3am Software Foundry.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32#include "SYS.h"
33
34#if defined(LIBC_SCCS) && !defined(lint)
35	RCSID("$NetBSD: brk.S,v 1.4 2015/03/31 11:59:41 matt Exp $")
36#endif /* LIBC_SCCS and not lint */
37
38	.hidden	_C_LABEL(__minbrk)
39	.hidden	_C_LABEL(__curbrk)
40	.globl	_C_LABEL(__minbrk)
41	.globl	_C_LABEL(__curbrk)
42	.globl	_C_LABEL(_end)
43
44#ifdef WEAK_ALIAS
45WEAK_ALIAS(brk, _brk)
46#endif
47
48	.data
49	.p2align	PTR_SCALESHIFT
50_C_LABEL(__minbrk):
51	PTR_WORD	_C_LABEL(_end)
52_C_LABEL(__curbrk):
53	PTR_WORD	_C_LABEL(_end)
54
55	.text
56
57ENTRY(_brk)
58	lla	t1, _C_LABEL(__minbrk)
59	PTR_L	t5, 0(t1)
60	bgeu	a0, t5, 1f
61	move	a0, t5		# dont allow break < minbrk
621:
63	SYSTRAP(break)
64	JUMP_TO_CERROR()				/* error */
65	PTR_S	a0, __SIZEOF_POINTER__(t1)		/* success */
66	move	a0, zero
67	ret
68END(_brk)
69