minix/lib/libc/arch/arm/sys/sbrk.S

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/* $NetBSD: sbrk.S,v 1.12 2013/09/12 15:36:15 joerg Exp $ */
/*-
* Copyright (c) 1990 The Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* from: @(#)sbrk.s 5.1 (Berkeley) 4/23/90
*/
#include "SYS.h"
.globl _C_LABEL(_end)
#ifdef WEAK_ALIAS
WEAK_ALIAS(sbrk, _sbrk)
#endif
.data
.align 0
.globl _C_LABEL(__curbrk)
.hidden _C_LABEL(__curbrk)
.type _C_LABEL(__curbrk),#object
_C_LABEL(__curbrk):
.word _C_LABEL(_end)
/*
* Change the data segment size
*/
ENTRY(_sbrk)
/* get address or offset to __curbrk */
ldr r2, .Lcurbrk
#ifdef __PIC__
add r2, r2, pc /* pc = &.LPIC0 */
#endif
/* Get the current brk address */
ldr r1, [r2]
/* Calculate new value */
.LPIC0: mov r3, r0
adds r0, r0, r1
SYSTRAP(break)
_INVOKE_CERROR()
/* Store new curbrk value */
ldr r0, [r2]
adds r1, r0, r3
str r1, [r2]
/* Return old curbrk value */
RET
.align 0
.Lcurbrk:
.word REL_SYM(_C_LABEL(__curbrk), .LPIC0)
END(_sbrk)