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brk.S revision 1.7.8.1 
      1  1.7.8.1    kleink /*	$NetBSD: brk.S,v 1.7.8.1 2000/08/22 07:23:25 kleink Exp $	*/
      2      1.3  christos 
      3      1.1       cgd /*
      4      1.1       cgd  * Copyright (c) 1992, 1993
      5      1.1       cgd  *	The Regents of the University of California.  All rights reserved.
      6      1.1       cgd  *
      7      1.1       cgd  * This software was developed by the Computer Systems Engineering group
      8      1.1       cgd  * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
      9      1.1       cgd  * contributed to Berkeley.
     10      1.1       cgd  *
     11      1.1       cgd  * Redistribution and use in source and binary forms, with or without
     12      1.1       cgd  * modification, are permitted provided that the following conditions
     13      1.1       cgd  * are met:
     14      1.1       cgd  * 1. Redistributions of source code must retain the above copyright
     15      1.1       cgd  *    notice, this list of conditions and the following disclaimer.
     16      1.1       cgd  * 2. Redistributions in binary form must reproduce the above copyright
     17      1.1       cgd  *    notice, this list of conditions and the following disclaimer in the
     18      1.1       cgd  *    documentation and/or other materials provided with the distribution.
     19      1.1       cgd  * 3. All advertising materials mentioning features or use of this software
     20      1.1       cgd  *    must display the following acknowledgement:
     21      1.1       cgd  *	This product includes software developed by the University of
     22      1.1       cgd  *	California, Berkeley and its contributors.
     23      1.1       cgd  * 4. Neither the name of the University nor the names of its contributors
     24      1.1       cgd  *    may be used to endorse or promote products derived from this software
     25      1.1       cgd  *    without specific prior written permission.
     26      1.1       cgd  *
     27      1.1       cgd  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     28      1.1       cgd  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     29      1.1       cgd  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     30      1.1       cgd  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     31      1.1       cgd  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     32      1.1       cgd  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     33      1.1       cgd  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     34      1.1       cgd  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     35      1.1       cgd  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     36      1.1       cgd  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     37      1.1       cgd  * SUCH DAMAGE.
     38      1.1       cgd  *
     39      1.1       cgd  * from: Header: brk.s,v 1.3 92/06/25 12:56:05 mccanne Exp
     40      1.1       cgd  */
     41      1.1       cgd 
     42      1.3  christos #include <machine/asm.h>
     43      1.3  christos #if defined(SYSLIBC_SCCS) && !defined(lint)
     44      1.3  christos #if 0
     45      1.1       cgd 	.asciz "@(#)brk.s	8.1 (Berkeley) 6/4/93"
     46      1.3  christos #else
     47  1.7.8.1    kleink 	RCSID("$NetBSD: brk.S,v 1.7.8.1 2000/08/22 07:23:25 kleink Exp $")
     48      1.3  christos #endif
     49      1.3  christos #endif /* SYSLIBC_SCCS and not lint */
     50      1.1       cgd 
     51      1.1       cgd #include "SYS.h"
     52      1.1       cgd 
     53      1.6    kleink 	.globl	CURBRK
     54      1.5    kleink 	.globl	_C_LABEL(__minbrk)
     55      1.7    kleink 	.globl	_end
     56      1.1       cgd 
     57  1.7.8.1    kleink #ifdef WEAK_ALIAS
     58  1.7.8.1    kleink WEAK_ALIAS(brk, _brk)
     59  1.7.8.1    kleink #endif
     60  1.7.8.1    kleink 
     61      1.1       cgd 	.data
     62      1.5    kleink _C_LABEL(__minbrk):
     63      1.7    kleink 	.long	_end			! lower brk limit; also for gmon code
     64      1.1       cgd 	.text
     65      1.1       cgd 
     66  1.7.8.1    kleink ENTRY(_brk)
     67      1.2        pk #ifdef PIC
     68      1.2        pk 	PIC_PROLOGUE(%o5,%o4)
     69      1.5    kleink 	ld	[%o5 + _C_LABEL(__minbrk)], %o4
     70      1.2        pk 	ld	[%o4], %o1		! %o1 = minbrk
     71      1.2        pk 	cmp	%o1, %o0		! if (minbrk > %o0)
     72      1.2        pk 	bg,a	0f
     73      1.2        pk 	 mov	%o1, %o0		!	%o0 = minbrk
     74      1.2        pk 0:
     75      1.2        pk 	mov	%o0, %o2		! save argument to syscall
     76      1.2        pk 	mov	SYS_break, %g1
     77      1.2        pk 	t	ST_SYSCALL
     78      1.2        pk 	bcc,a	1f
     79      1.6    kleink 	ld	[%o5 + CURBRK], %o4
     80      1.2        pk 	ERROR()
     81      1.2        pk 1:
     82      1.2        pk 	retl				! success, return 0 & record new break
     83      1.2        pk 	 st	%o2, [%o4]
     84      1.2        pk #else
     85      1.5    kleink 	sethi	%hi(_C_LABEL(__minbrk)), %o1	! %o1 = minbrk
     86      1.5    kleink 	ld	[%o1 + %lo(_C_LABEL(__minbrk))], %o1
     87      1.1       cgd 	cmp	%o1, %o0		! if (minbrk > %o0)
     88      1.1       cgd 	bg,a	0f
     89      1.1       cgd 	 mov	%o1, %o0		!	%o0 = minbrk
     90      1.1       cgd 0:
     91      1.1       cgd 	mov	%o0, %o2		! save argument to syscall
     92      1.1       cgd 	mov	SYS_break, %g1
     93      1.1       cgd 	t	ST_SYSCALL
     94      1.1       cgd 	bcc,a	1f
     95      1.6    kleink 	 sethi	%hi(CURBRK), %g1
     96      1.1       cgd 	ERROR()
     97      1.1       cgd 1:
     98      1.1       cgd 	retl				! success, return 0 & record new break
     99      1.6    kleink 	 st	%o2, [%g1 + %lo(CURBRK)]
    100      1.2        pk #endif
    101