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brk.S revision 1.4 
      1 /*	$NetBSD: brk.S,v 1.4 1998/07/01 02:16:28 tv 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: brk.s,v 1.3 92/06/25 12:56:05 mccanne Exp
     40  */
     41 
     42 #include <machine/asm.h>
     43 #if defined(SYSLIBC_SCCS) && !defined(lint)
     44 #if 0
     45 	.asciz "@(#)brk.s	8.1 (Berkeley) 6/4/93"
     46 #else
     47 	RCSID("$NetBSD: brk.S,v 1.4 1998/07/01 02:16:28 tv Exp $")
     48 #endif
     49 #endif /* SYSLIBC_SCCS and not lint */
     50 
     51 #include "SYS.h"
     52 
     53 	.globl	curbrk
     54 	.globl	minbrk
     55 
     56 	.data
     57 minbrk:	.long	_C_LABEL(end)		! lower brk limit; also for gmon code
     58 	.text
     59 
     60 #ifdef PIC
     61 ENTRY(brk)
     62 	PIC_PROLOGUE(%o5,%o4)
     63 	ld	[%o5 + minbrk], %o4
     64 	ld	[%o4], %o1		! %o1 = minbrk
     65 	cmp	%o1, %o0		! if (minbrk > %o0)
     66 	bg,a	0f
     67 	 mov	%o1, %o0		!	%o0 = minbrk
     68 0:
     69 	mov	%o0, %o2		! save argument to syscall
     70 	mov	SYS_break, %g1
     71 	t	ST_SYSCALL
     72 	bcc,a	1f
     73 	ld	[%o5 + curbrk], %o4
     74 	ERROR()
     75 1:
     76 	retl				! success, return 0 & record new break
     77 	 st	%o2, [%o4]
     78 #else
     79 ENTRY(brk)
     80 	sethi	%hi(minbrk), %o1	! %o1 = minbrk
     81 	ld	[%o1 + %lo(minbrk)], %o1
     82 	cmp	%o1, %o0		! if (minbrk > %o0)
     83 	bg,a	0f
     84 	 mov	%o1, %o0		!	%o0 = minbrk
     85 0:
     86 	mov	%o0, %o2		! save argument to syscall
     87 	mov	SYS_break, %g1
     88 	t	ST_SYSCALL
     89 	bcc,a	1f
     90 	 sethi	%hi(curbrk), %g1
     91 	ERROR()
     92 1:
     93 	retl				! success, return 0 & record new break
     94 	 st	%o2, [%g1 + %lo(curbrk)]
     95 #endif
     96