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sbrk.S revision 1.9 
      1 /*	$NetBSD: sbrk.S,v 1.9 2003/08/07 16:42:26 agc Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1992, 1993
      5  *	The Regents of the University of California.  All rights reserved.
      6  *
      7  * This software was developed by the Computer Systems Engineering group
      8  * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
      9  * contributed to Berkeley.
     10  *
     11  * Redistribution and use in source and binary forms, with or without
     12  * modification, are permitted provided that the following conditions
     13  * are met:
     14  * 1. Redistributions of source code must retain the above copyright
     15  *    notice, this list of conditions and the following disclaimer.
     16  * 2. Redistributions in binary form must reproduce the above copyright
     17  *    notice, this list of conditions and the following disclaimer in the
     18  *    documentation and/or other materials provided with the distribution.
     19  * 3. 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: Header: sbrk.s,v 1.3 92/07/02 00:56:49 torek Exp
     36  */
     37 
     38 #include <machine/asm.h>
     39 #if defined(SYSLIBC_SCCS) && !defined(lint)
     40 #if 0
     41 	.asciz "@(#)sbrk.s	8.1 (Berkeley) 6/4/93"
     42 #else
     43 	RCSID("$NetBSD: sbrk.S,v 1.9 2003/08/07 16:42:26 agc Exp $")
     44 #endif
     45 #endif /* SYSLIBC_SCCS and not lint */
     46 
     47 #include "SYS.h"
     48 
     49 	.globl	_end
     50 	.globl	CURBRK
     51 
     52 #ifdef WEAK_ALIAS
     53 WEAK_ALIAS(sbrk, _sbrk)
     54 #endif
     55 
     56 	.data
     57 CURBRK:	.long	_end
     58 	.text
     59 
     60 ENTRY(_sbrk)
     61 #ifdef PIC
     62 	PIC_PROLOGUE(%o5,%o4)
     63 	ld	[%o5 + CURBRK], %o2
     64 	ld	[%o2], %o3			! %o3 = old break
     65 	add	%o3, %o0, %o4			! %o4 = new break
     66 	mov	%o4, %o0			! copy for syscall
     67 	mov	SYS_break, %g1
     68 	t	ST_SYSCALL			! break(new_break)
     69 	bcc,a	1f				! if success,
     70 	 mov	%o3, %o0			!    set return value
     71 	ERROR()
     72 1:
     73 	retl					! and update curbrk
     74 	 st	%o4, [%o2]
     75 #else
     76 	sethi	%hi(CURBRK), %o2
     77 	ld	[%o2 + %lo(CURBRK)], %o3	! %o3 = old break
     78 	add	%o3, %o0, %o4			! %o4 = new break
     79 	mov	%o4, %o0			! copy for syscall
     80 	mov	SYS_break, %g1
     81 	t	ST_SYSCALL			! break(new_break)
     82 	bcc,a	1f				! if success,
     83 	 mov	%o3, %o0			!    set return value
     84 	ERROR()
     85 1:
     86 	retl					! and update curbrk
     87 	 st	%o4, [%o2 + %lo(CURBRK)]
     88 #endif
     89