2015-10-15 10:25:28 +02:00

73 lines
2.3 KiB
ArmAsm

/* $NetBSD: brk.S,v 1.1 2014/08/10 05:47:37 matt Exp $ */
/*-
* Copyright (c) 2014 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Matt Thomas of 3am Software Foundry.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
*/
#include "SYS.h"
.globl _C_LABEL(_end)
.globl _C_LABEL(__curbrk)
WEAK_ALIAS(brk, _brk)
.data
.globl _C_LABEL(__minbrk)
.hidden _C_LABEL(__minbrk)
.type _C_LABEL(__minbrk),#object
.align 3
_C_LABEL(__minbrk):
.xword _C_LABEL(_end)
.size _C_LABEL(__minbrk), 8
/*
* Change the data segment size
*/
ENTRY(_brk)
adr x9, _C_LABEL(__minbrk)
ldr x10, [x9, #:lo12:_C_LABEL(__minbrk)]
/*
* Valid the address specified and set to the minimum
* if the address is below minbrk.
*/
cmp x0, x10
csel x0, x10, x0, lt
mov x11, x0
SYSTRAP(break)
_INVOKE_CERROR()
/* Store the new address in curbrk */
adr x9, _C_LABEL(__curbrk)
str x11, [x9, #:lo12:_C_LABEL(__curbrk)]
/* Return 0 for success */
mov x0, xzr
ret
END(_brk)