/*      $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