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brk.S revision 1.13 
      1 /*	$NetBSD: brk.S,v 1.13 2001/05/05 17:46:37 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 1.13 2001/05/05 17:46:37 kleink Exp $")
     47 #endif
     48 #endif /* LIBC_SCCS and not lint */
     49 
     50 	.globl	_end
     51 	.globl	_C_LABEL(__minbrk)
     52 	.globl	CURBRK
     53 
     54 #ifdef WEAK_ALIAS
     55 WEAK_ALIAS(brk, _brk)
     56 #endif
     57 
     58 	.data
     59 _C_LABEL(__minbrk):
     60 	.long	_end
     61 
     62 	.text
     63 
     64 ENTRY(_brk)
     65 #ifdef	PIC
     66 #ifdef	__ELF__
     67 	lea	%pc@(_GLOBAL_OFFSET_TABLE_@GOTPC),%a1
     68 	movl	%a1@(_C_LABEL(__minbrk)@GOT:w),%a0
     69 #else
     70 	movl	#_C_LABEL(_GLOBAL_OFFSET_TABLE_),%a1
     71 	lea	%pc@(0,a1:l),%a1
     72 	movl	%a1@(_C_LABEL(__minbrk):w),%a0
     73 #endif
     74 	movl	%a0@,%d0
     75 #else
     76 	movl	_C_LABEL(__minbrk),%d0
     77 #endif
     78 	cmpl	%sp@(4),%d0
     79 	jle	ok
     80 	movl	%d0,%sp@(4)
     81 ok:
     82 	movl	#SYS_break,%d0
     83 	trap	#0
     84 	jcs	err
     85 #ifdef	PIC
     86 #ifdef	__ELF__
     87 	movl	%a1@(CURBRK@GOT:w),%a0
     88 #else
     89 	movl	%a1@(CURBRK:w),%a0
     90 #endif
     91 	movl	%sp@(4),%a0@
     92 #else
     93 	movl	%sp@(4),CURBRK
     94 #endif
     95 	clrl	%d0
     96 	rts
     97 err:
     98 	jra	PIC_PLT(CERROR)
     99