Home | History | Annotate | Line # | Download | only in sys
sbrk.S revision 1.2.2.1 
      1 /*	$NetBSD: sbrk.S,v 1.2.2.1 2001/10/08 20:17:10 nathanw 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. All advertising materials mentioning features or use of this software
     16  *    must display the following acknowledgement:
     17  *	This product includes software developed by the University of
     18  *	California, Berkeley and its contributors.
     19  * 4. Neither the name of the University nor the names of its contributors
     20  *    may be used to endorse or promote products derived from this software
     21  *    without specific prior written permission.
     22  *
     23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     33  * SUCH DAMAGE.
     34  *
     35  *	from: @(#)sbrk.s	5.1 (Berkeley) 4/23/90
     36  */
     37 
     38 #include "SYS.h"
     39 
     40 	.globl	_C_LABEL(end)
     41 
     42 #ifdef WEAK_ALIAS
     43 WEAK_ALIAS(sbrk, _sbrk)
     44 #endif
     45 
     46 	.data
     47 	.align	0
     48 	.globl	CURBRK
     49 	.type	CURBRK,#object
     50 CURBRK:
     51 	.word	_C_LABEL(end)
     52 
     53 /*
     54  * Change the data segment size
     55  */
     56 ENTRY(_sbrk)
     57 #ifdef PIC
     58 	/* Setup the GOT */
     59 	ldr	r3, Lgot
     60 	add	r3, pc, r3
     61 .L1:
     62 	ldr	r2, Lcurbrk
     63 	ldr	r2, [r3, r2]
     64 #else
     65 	ldr	r2, Lcurbrk
     66 #endif
     67 	/* Get the current brk address */
     68 	ldr	r1, [r2]
     69 
     70 	/* Calculate new value */
     71 	mov	r3, r0
     72 	add	r0, r0, r1
     73 	SYSTRAP(break)
     74 	bcs	PIC_SYM(CERROR, PLT)
     75 
     76 	/* Store new curbrk value */
     77 	ldr	r0, [r2]
     78 	add	r1, r0, r3
     79 	str	r1, [r2]
     80 
     81 	/* Return old curbrk value */
     82 #ifdef __APCS_26__
     83 	movs	r15, r14
     84 #else
     85 	mov	r15, r14
     86 #endif
     87 
     88 	.align	0
     89 #ifdef PIC
     90 Lgot:
     91 	.word	_C_LABEL(_GLOBAL_OFFSET_TABLE_) + (. - (.L1+4))
     92 #endif
     93 Lcurbrk:
     94 	.word	PIC_SYM(CURBRK, GOT)
     95