minix/lib/libc/arch/sparc/sys/brk.S

/*	$NetBSD: brk.S,v 1.16 2013/09/12 15:36:16 joerg Exp $	*/

/*
 * Copyright (c) 1992, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * This software was developed by the Computer Systems Engineering group
 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
 * contributed to Berkeley.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * from: Header: brk.s,v 1.3 92/06/25 12:56:05 mccanne Exp
 */

#include <machine/asm.h>
#if defined(SYSLIBC_SCCS) && !defined(lint)
#if 0
	.asciz "@(#)brk.s	8.1 (Berkeley) 6/4/93"
#else
	RCSID("$NetBSD: brk.S,v 1.16 2013/09/12 15:36:16 joerg Exp $")
#endif
#endif /* SYSLIBC_SCCS and not lint */

#include "SYS.h"

	.globl	CURBRK
	.globl	_C_LABEL(__minbrk)
	.globl	_end

#ifdef WEAK_ALIAS
WEAK_ALIAS(brk, _brk)
#endif

	.data
_C_LABEL(__minbrk):
	.long	_end			! lower brk limit; also for gmon code
	.text

ENTRY(_brk)
#ifdef __PIC__
	PIC_PROLOGUE(%o5,%o4)
	set	_C_LABEL(__minbrk), %o4
	ld	[%o5 + %o4], %o4
	ld	[%o4], %o1		! %o1 = minbrk
	cmp	%o1, %o0		! if (minbrk > %o0)
	bgu,a	0f
	 mov	%o1, %o0		!	%o0 = minbrk
0:
	mov	%o0, %o2		! save argument to syscall
	mov	SYS_break, %g1
	t	ST_SYSCALL
	set	CURBRK, %o3
	bcc,a	1f
	 ld	[%o5 + %o3], %o4
	ERROR()
1:
	retl				! success, return 0 & record new break
	 st	%o2, [%o4]
#else
	sethi	%hi(_C_LABEL(__minbrk)), %o1	! %o1 = minbrk
	ld	[%o1 + %lo(_C_LABEL(__minbrk))], %o1
	cmp	%o1, %o0		! if (minbrk > %o0)
	bgu,a	0f
	 mov	%o1, %o0		!	%o0 = minbrk
0:
	mov	%o0, %o2		! save argument to syscall
	mov	SYS_break, %g1
	t	ST_SYSCALL
	bcc,a	1f
	 sethi	%hi(CURBRK), %g1
	ERROR()
1:
	retl				! success, return 0 & record new break
	 st	%o2, [%g1 + %lo(CURBRK)]
#endif