xref: /minix3/lib/libc/arch/arm/sys/brk.S (revision 84d9c625bfea59e274550651111ae9edfdc40fbd)
1*84d9c625SLionel Sambuc/*	$NetBSD: brk.S,v 1.13 2013/09/12 15:36:15 joerg Exp $	*/
22fe8fb19SBen Gras
32fe8fb19SBen Gras/*-
42fe8fb19SBen Gras * Copyright (c) 1990 The Regents of the University of California.
52fe8fb19SBen Gras * All rights reserved.
62fe8fb19SBen Gras *
72fe8fb19SBen Gras * Redistribution and use in source and binary forms, with or without
82fe8fb19SBen Gras * modification, are permitted provided that the following conditions
92fe8fb19SBen Gras * are met:
102fe8fb19SBen Gras * 1. Redistributions of source code must retain the above copyright
112fe8fb19SBen Gras *    notice, this list of conditions and the following disclaimer.
122fe8fb19SBen Gras * 2. Redistributions in binary form must reproduce the above copyright
132fe8fb19SBen Gras *    notice, this list of conditions and the following disclaimer in the
142fe8fb19SBen Gras *    documentation and/or other materials provided with the distribution.
152fe8fb19SBen Gras * 3. Neither the name of the University nor the names of its contributors
162fe8fb19SBen Gras *    may be used to endorse or promote products derived from this software
172fe8fb19SBen Gras *    without specific prior written permission.
182fe8fb19SBen Gras *
192fe8fb19SBen Gras * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
202fe8fb19SBen Gras * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
212fe8fb19SBen Gras * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
222fe8fb19SBen Gras * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
232fe8fb19SBen Gras * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
242fe8fb19SBen Gras * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
252fe8fb19SBen Gras * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
262fe8fb19SBen Gras * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
272fe8fb19SBen Gras * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
282fe8fb19SBen Gras * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
292fe8fb19SBen Gras * SUCH DAMAGE.
302fe8fb19SBen Gras *
312fe8fb19SBen Gras *	from: @(#)brk.s	5.2 (Berkeley) 12/17/90
322fe8fb19SBen Gras */
332fe8fb19SBen Gras
342fe8fb19SBen Gras#include "SYS.h"
352fe8fb19SBen Gras
36f14fb602SLionel Sambuc	.globl	_C_LABEL(_end)
37*84d9c625SLionel Sambuc	.globl	_C_LABEL(__curbrk)
382fe8fb19SBen Gras
392fe8fb19SBen Gras#ifdef WEAK_ALIAS
402fe8fb19SBen GrasWEAK_ALIAS(brk, _brk)
412fe8fb19SBen Gras#endif
422fe8fb19SBen Gras
432fe8fb19SBen Gras	.data
442fe8fb19SBen Gras	.align	0
452fe8fb19SBen Gras	.globl	_C_LABEL(__minbrk)
46*84d9c625SLionel Sambuc	.hidden	_C_LABEL(__minbrk)
472fe8fb19SBen Gras	.type	_C_LABEL(__minbrk),#object
482fe8fb19SBen Gras_C_LABEL(__minbrk):
49f14fb602SLionel Sambuc	.word	_C_LABEL(_end)
502fe8fb19SBen Gras
512fe8fb19SBen Gras/*
522fe8fb19SBen Gras * Change the data segment size
532fe8fb19SBen Gras */
542fe8fb19SBen GrasENTRY(_brk)
552fe8fb19SBen Gras	ldr	r1, .Lminbrk
56*84d9c625SLionel Sambuc#ifdef __PIC__
57*84d9c625SLionel Sambuc	adr	r3, .Lminbrk
58*84d9c625SLionel Sambuc	adds	r1, r1, r3
592fe8fb19SBen Gras#endif
602fe8fb19SBen Gras	/* Get the minimum allowable brk address */
612fe8fb19SBen Gras	ldr	r1, [r1]
622fe8fb19SBen Gras
632fe8fb19SBen Gras	/*
642fe8fb19SBen Gras	 * Valid the address specified and set to the minimum
652fe8fb19SBen Gras	 * if the address is below minbrk.
662fe8fb19SBen Gras	 */
672fe8fb19SBen Gras	cmp	r0, r1
68*84d9c625SLionel Sambuc#ifdef __thumb__
69*84d9c625SLionel Sambuc	bcs	1f
70*84d9c625SLionel Sambuc	mov	r0, r1
71*84d9c625SLionel Sambuc1:
72*84d9c625SLionel Sambuc#else
732fe8fb19SBen Gras	movcc	r0, r1
74*84d9c625SLionel Sambuc#endif
752fe8fb19SBen Gras	mov	r2, r0
762fe8fb19SBen Gras	SYSTRAP(break)
77*84d9c625SLionel Sambuc	_INVOKE_CERROR()
782fe8fb19SBen Gras
792fe8fb19SBen Gras	ldr	r1, .Lcurbrk
80*84d9c625SLionel Sambuc#ifdef __PIC__
81*84d9c625SLionel Sambuc	adds	r1, r1, r3
822fe8fb19SBen Gras#endif
832fe8fb19SBen Gras	/* Store the new address in curbrk */
842fe8fb19SBen Gras	str	r2, [r1]
852fe8fb19SBen Gras
862fe8fb19SBen Gras	/* Return 0 for success */
87*84d9c625SLionel Sambuc	movs	r0, #0
882fe8fb19SBen Gras	RET
892fe8fb19SBen Gras
90*84d9c625SLionel Sambuc	.align	0
912fe8fb19SBen Gras.Lminbrk:
92*84d9c625SLionel Sambuc	.word	REL_SYM(_C_LABEL(__minbrk), .Lminbrk)
932fe8fb19SBen Gras.Lcurbrk:
94*84d9c625SLionel Sambuc	.word	REL_SYM(_C_LABEL(__curbrk), .Lminbrk)
95*84d9c625SLionel SambucEND(_brk)
96