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brk.S revision 1.7 
      1 /*	$NetBSD: brk.S,v 1.7 1999/01/14 22:48:20 kleink 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  * the Systems Programming Group of the University of Utah Computer
      9  * Science Department.
     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 
     40 #include "SYS.h"
     41 
     42 #if defined(LIBC_SCCS) && !defined(lint)
     43 #if 0
     44 	RCSID("from: @(#)brk.s	5.1 (Berkeley) 5/12/90")
     45 #else
     46 	RCSID("$NetBSD: brk.S,v 1.7 1999/01/14 22:48:20 kleink Exp $")
     47 #endif
     48 #endif /* LIBC_SCCS and not lint */
     49 
     50 	.globl	_C_LABEL(end)
     51 	.globl	_C_LABEL(__minbrk)
     52 	.globl	CURBRK
     53 
     54 	.data
     55 _C_LABEL(__minbrk):
     56 	.long	_C_LABEL(end)
     57 	.text
     58 
     59 ENTRY(brk)
     60 #ifdef	PIC
     61 	movl	#_C_LABEL(_GLOBAL_OFFSET_TABLE_),a1
     62 	lea	pc@(0,a1:l),a1
     63 	movl	a1@(_C_LABEL(__minbrk):w),a0
     64 	movl	a0@,d0
     65 #else
     66 	movl	_C_LABEL(__minbrk),d0
     67 #endif
     68 	cmpl	sp@(4),d0
     69 	jle	ok
     70 	movl	d0,sp@(4)
     71 ok:
     72 	movl	#SYS_break,d0
     73 	trap	#0
     74 	jcs	err
     75 #ifdef	PIC
     76 	movl	a1@(CURBRK:w),a0
     77 	movl	sp@(4),a0@
     78 #else
     79 	movl	sp@(4),CURBRK
     80 #endif
     81 	clrl	d0
     82 	rts
     83 err:
     84 	jra	CERROR
     85