freebsd-skq/lib/libc/arm/sys/brk.S
kan 45bdca2b2d Use built-in _end symbol insteadof 'end' for consistency with other
architectures. Linker defines end is synonym for _end.
2007-05-19 04:36:34 +00:00

101 lines
2.7 KiB
ArmAsm

/* $NetBSD: brk.S,v 1.6 2003/08/07 16:42:04 agc 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: @(#)brk.s 5.2 (Berkeley) 12/17/90
*/
#include <machine/asm.h>
__FBSDID("$FreeBSD$");
#include "SYS.h"
.globl _C_LABEL(_end)
.globl CURBRK
#ifdef WEAK_ALIAS
WEAK_ALIAS(brk, _brk)
#endif
.data
.align 0
.globl _C_LABEL(minbrk)
.type _C_LABEL(minbrk),#object
_C_LABEL(minbrk):
.word _C_LABEL(_end)
/*
* Change the data segment size
*/
ENTRY(_brk)
#ifdef PIC
/* Setup the GOT */
ldr r3, .Lgot
add r3, pc, r3
.L1:
ldr r1, .Lminbrk
ldr r1, [r3, r1]
#else
ldr r1, .Lminbrk
#endif
/* Get the minimum allowable brk address */
ldr r1, [r1]
/*
* Valid the address specified and set to the minimum
* if the address is below minbrk.
*/
cmp r0, r1
movlt r0, r1
mov r2, r0
SYSTRAP(break)
bcs PIC_SYM(CERROR, PLT)
#ifdef PIC
ldr r1, .Lcurbrk
ldr r1, [r3, r1]
#else
ldr r1, .Lcurbrk
#endif
/* Store the new address in curbrk */
str r2, [r1]
/* Return 0 for success */
mov r0, #0x00000000
RET
.align 2
#ifdef PIC
.Lgot:
.word _GLOBAL_OFFSET_TABLE_ - (.L1+4)
#endif
.Lminbrk:
.word PIC_SYM(_C_LABEL(minbrk), GOT)
.Lcurbrk:
.word PIC_SYM(CURBRK, GOT)