freebsd-dev/lib/libc/aarch64/sys/brk.S
Andrew Turner d422e6f9b5 Add the start of libc and libstand for arm64. Not all of the machine
dependent functions have been implemented, but this is enough for world.

Differential Revision:	https://reviews.freebsd.org/D2132
Reviewed by:	emaste
Sponsored by:	The FreeBSD Foundation
2015-04-07 09:52:14 +00:00

94 lines
2.4 KiB
ArmAsm

/*-
* Copyright (c) 2014 The FreeBSD Foundation
* All rights reserved.
*
* This software was developed by Andrew Turner under
* sponsorship from the FreeBSD Foundation.
*
* 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 AUTHOR 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 AUTHOR 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 <machine/asm.h>
__FBSDID("$FreeBSD$");
#include "SYS.h"
.data
.align 3
.globl _C_LABEL(minbrk)
.type _C_LABEL(minbrk),#object
_C_LABEL(minbrk):
.quad _C_LABEL(_end)
.text
/*
* int brk(const void *addr);
*/
ENTRY(_brk)
WEAK_REFERENCE(_brk, brk)
/* Load the address of minbrk */
#ifdef __PIC__
adrp x2, :got:minbrk
ldr x3, [x2, #:got_lo12:minbrk]
#else
ldr x3, .Lminbrk
#endif
/* Get the minimum allowable brk address */
ldr x2, [x3]
/* Validate the address */
cmp x0, x2
b.ge 1f
/* Invalid, set it to the minimum */
mov x0, x2
/* Backup the new address */
1: mov x4, x0
/* Update for this value, will overwrite x0 and x1 */
_SYSCALL(break)
b.cs cerror
#ifdef __PIC__
adrp x2, :got:curbrk
ldr x3, [x2, #:got_lo12:curbrk]
#else
ldr x3, .Lcurbrk
#endif
/* Store the new curbrk value */
str x4, [x3]
/* Return success */
mov x0, #0
ret
#ifndef __PIC__
.Lcurbrk:
.quad _C_LABEL(curbrk)
.Lminbrk:
.quad _C_LABEL(minbrk)
#endif
END(_brk)