Home | History | Annotate | Line # | Download | only in sys
brk.S revision 1.6 
      1 /*-
      2  * Copyright (c) 1990 The Regents of the University of California.
      3  * All rights reserved.
      4  *
      5  * This code is derived from software contributed to Berkeley by
      6  * William Jolitz.
      7  *
      8  * Redistribution and use in source and binary forms, with or without
      9  * modification, are permitted provided that the following conditions
     10  * are met:
     11  * 1. Redistributions of source code must retain the above copyright
     12  *    notice, this list of conditions and the following disclaimer.
     13  * 2. Redistributions in binary form must reproduce the above copyright
     14  *    notice, this list of conditions and the following disclaimer in the
     15  *    documentation and/or other materials provided with the distribution.
     16  * 3. All advertising materials mentioning features or use of this software
     17  *    must display the following acknowledgement:
     18  *	This product includes software developed by the University of
     19  *	California, Berkeley and its contributors.
     20  * 4. Neither the name of the University nor the names of its contributors
     21  *    may be used to endorse or promote products derived from this software
     22  *    without specific prior written permission.
     23  *
     24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     34  * SUCH DAMAGE.
     35  *
     36  *	from: @(#)brk.s	5.2 (Berkeley) 12/17/90
     37  *	$Id: brk.S,v 1.6 1994/01/27 04:30:34 mycroft Exp $
     38  */
     39 
     40 #if defined(SYSLIBC_SCCS) && !defined(lint)
     41 	.text
     42 	.asciz "$Id: brk.S,v 1.6 1994/01/27 04:30:34 mycroft Exp $"
     43 #endif /* SYSLIBC_SCCS and not lint */
     44 
     45 #include "SYS.h"
     46 
     47 	.globl	curbrk
     48 	.globl	minbrk
     49 ENTRY(_brk)
     50 	jmp	ok
     51 
     52 ENTRY(brk)
     53 #ifdef PIC
     54 	movl	4(%esp),%eax
     55 	PIC_PROLOGUE
     56 	movl	PIC_GOT(curbrk),%edx	# set up GOT addressing
     57 	movl	PIC_GOT(minbrk),%ecx	#
     58 	cmpl	%eax,(%ecx)
     59 	PIC_EPILOGUE
     60 	jl	ok
     61 	movl	(%ecx),%eax
     62 	movl	%eax,4(%esp)
     63 ok:
     64 	movl	$(SYS_break),%eax
     65 	LCALL(7,0)
     66 	jb	err
     67 	movl	4(%esp),%eax
     68 	movl	%eax,(%edx)
     69 	xorl	%eax,%eax
     70 	ret
     71 err:
     72 	jmp	PIC_PLT(cerror)
     73 
     74 #else
     75 
     76 	movl	4(%esp),%eax
     77 	cmpl	%eax,minbrk
     78 	jl	ok
     79 	movl	minbrk,%eax
     80 	movl	%eax,4(%esp)
     81 ok:
     82 	movl	$(SYS_break),%eax
     83 	LCALL(7,0)
     84 	jb	err
     85 	movl	4(%esp),%eax
     86 	movl	%eax,curbrk
     87 	xorl	%eax,%eax
     88 	ret
     89 err:
     90 	jmp	cerror
     91 #endif
     92