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sbrk.S revision 1.9.10.1 
      1 /*	$NetBSD: sbrk.S,v 1.9.10.1 2014/08/20 00:02:09 tls Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1990 The Regents of the University of California.
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. Neither the name of the University nor the names of its contributors
     16  *    may be used to endorse or promote products derived from this software
     17  *    without specific prior written permission.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     29  * SUCH DAMAGE.
     30  *
     31  *	from: @(#)sbrk.s	5.1 (Berkeley) 4/23/90
     32  */
     33 
     34 #include "SYS.h"
     35 
     36 	.globl	_C_LABEL(_end)
     37 
     38 #ifdef WEAK_ALIAS
     39 WEAK_ALIAS(sbrk, _sbrk)
     40 #endif
     41 
     42 	.data
     43 	.align	0
     44 	.globl	_C_LABEL(__curbrk)
     45 	.hidden	_C_LABEL(__curbrk)
     46 	.type	_C_LABEL(__curbrk),#object
     47 _C_LABEL(__curbrk):
     48 	.word	_C_LABEL(_end)
     49 
     50 /*
     51  * Change the data segment size
     52  */
     53 ENTRY(_sbrk)
     54 	/* get address or offset to __curbrk */
     55 	ldr	r2, .Lcurbrk
     56 #ifdef __PIC__
     57 	add	r2, r2, pc	/* pc = &.LPIC0 */
     58 #endif
     59 
     60 	/* Get the current brk address */
     61 	ldr	r1, [r2]
     62 
     63 	/* Calculate new value */
     64 .LPIC0:	mov	r3, r0
     65 	adds	r0, r0, r1
     66 	SYSTRAP(break)
     67 	_INVOKE_CERROR()
     68 
     69 	/* Store new curbrk value */
     70 	ldr	r0, [r2]
     71 	adds	r1, r0, r3
     72 	str	r1, [r2]
     73 
     74 	/* Return old curbrk value */
     75 	RET
     76 
     77 	.align	0
     78 .Lcurbrk:
     79 	.word	REL_SYM(_C_LABEL(__curbrk), .LPIC0)
     80 END(_sbrk)
     81