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brk.S revision 1.10 
      1 /*	$NetBSD: brk.S,v 1.10 1997/07/16 14:37:27 christos Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1990 The Regents of the University of California.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to Berkeley by
      8  * William Jolitz.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  * 3. All advertising materials mentioning features or use of this software
     19  *    must display the following acknowledgement:
     20  *	This product includes software developed by the University of
     21  *	California, Berkeley and its contributors.
     22  * 4. Neither the name of the University nor the names of its contributors
     23  *    may be used to endorse or promote products derived from this software
     24  *    without specific prior written permission.
     25  *
     26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     36  * SUCH DAMAGE.
     37  *
     38  *	from: @(#)brk.s	5.2 (Berkeley) 12/17/90
     39  */
     40 
     41 #include <machine/asm.h>
     42 #if defined(SYSLIBC_SCCS) && !defined(lint)
     43 	RCSID("$NetBSD: brk.S,v 1.10 1997/07/16 14:37:27 christos Exp $")
     44 #endif /* SYSLIBC_SCCS and not lint */
     45 
     46 #include "SYS.h"
     47 
     48 	.globl	_end
     49 	.globl	minbrk
     50 	.globl	curbrk
     51 
     52 	.data
     53 minbrk:	.long	_end
     54 	.text
     55 
     56 ENTRY(brk)
     57 #ifdef PIC
     58 	movl	4(%esp),%ecx
     59 	PIC_PROLOGUE
     60 	movl	PIC_GOT(minbrk),%edx
     61 	PIC_EPILOGUE
     62 	cmpl	%ecx,(%edx)
     63 	jl	1f
     64 	movl	(%edx),%ecx
     65 	movl	%ecx,4(%esp)
     66 1:
     67 	movl	$(SYS_break),%eax
     68 	int	$0x80
     69 	jc	err
     70 	PIC_PROLOGUE
     71 	movl	PIC_GOT(curbrk),%edx	# set up GOT addressing
     72 	PIC_EPILOGUE
     73 	xorl	%eax,%eax
     74 	movl	%ecx,(%edx)
     75 	ret
     76 err:
     77 	jmp	PIC_PLT(cerror)
     78 
     79 #else
     80 
     81 	movl	4(%esp),%ecx
     82 	cmpl	%ecx,minbrk
     83 	jl	1f
     84 	movl	minbrk,%ecx
     85 	movl	%ecx,4(%esp)
     86 1:
     87 	movl	$(SYS_break),%eax
     88 	int	$0x80
     89 	jc	err
     90 	xorl	%eax,%eax
     91 	movl	%ecx,curbrk
     92 	ret
     93 err:
     94 	jmp	cerror
     95 #endif
     96