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sbrk.S revision 1.6 
      1 /*	$NetBSD: sbrk.S,v 1.6 2000/07/18 22:39:25 eeh 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. All advertising materials mentioning features or use of this software
     20  *    must display the following acknowledgement:
     21  *	This product includes software developed by the University of
     22  *	California, Berkeley and its contributors.
     23  * 4. Neither the name of the University nor the names of its contributors
     24  *    may be used to endorse or promote products derived from this software
     25  *    without specific prior written permission.
     26  *
     27  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     28  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     29  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     30  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     31  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     32  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     33  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     34  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     35  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     36  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     37  * SUCH DAMAGE.
     38  *
     39  * from: Header: sbrk.s,v 1.3 92/07/02 00:56:49 torek Exp
     40  */
     41 
     42 #include <machine/asm.h>
     43 #if defined(SYSLIBC_SCCS) && !defined(lint)
     44 #if 0
     45 	.asciz "@(#)sbrk.s	8.1 (Berkeley) 6/4/93"
     46 #else
     47 	RCSID("$NetBSD: sbrk.S,v 1.6 2000/07/18 22:39:25 eeh Exp $")
     48 #endif
     49 #endif /* SYSLIBC_SCCS and not lint */
     50 
     51 #include "SYS.h"
     52 
     53 	.globl	_C_LABEL(__curbrk)
     54 	.globl	_C_LABEL(_end)
     55 
     56 #ifdef WEAK_ALIAS
     57 WEAK_ALIAS(sbrk, _sbrk)
     58 #endif
     59 
     60 	.data
     61 	.align	8
     62 _C_LABEL(__curbrk):
     63 	.xword	_C_LABEL(_end)
     64 	.text
     65 
     66 ENTRY(_sbrk)
     67 #ifdef PIC
     68 	PIC_PROLOGUE(%o5,%o4)
     69 	set	_C_LABEL(__curbrk), %o3
     70 	ldx	[%o5 + %o3], %o2
     71 	ldx	[%o2], %o3			! %o3 = old break
     72 	add	%o3, %o0, %o4			! %o4 = new break
     73 	mov	%o4, %o0			! copy for syscall
     74 	mov	SYS_break, %g1
     75 	t	ST_SYSCALL			! break(new_break)
     76 	bcc,a	1f				! if success,
     77 	 mov	%o3, %o0			!    set return value
     78 	ERROR()
     79 1:
     80 	retl					! and update curbrk
     81 	 stx	%o4, [%o2]
     82 #else
     83 	sethi	%hi(_C_LABEL(__curbrk)), %o2
     84 	ldx	[%o2 + %lo(_C_LABEL(__curbrk))], %o3	! %o3 = old break
     85 	add	%o3, %o0, %o4			! %o4 = new break
     86 	mov	%o4, %o0			! copy for syscall
     87 	mov	SYS_break, %g1
     88 	t	ST_SYSCALL			! break(new_break)
     89 	bcc,a	1f				! if success,
     90 	 mov	%o3, %o0			!    set return value
     91 	ERROR()
     92 1:
     93 	retl					! and update curbrk
     94 	 stx	%o4, [%o2 + %lo(_C_LABEL(__curbrk))]
     95 #endif
     96