/*      $OpenBSD: brk.S,v 1.12 2023/12/10 16:45:52 deraadt Exp $        */
/*      $NetBSD: brk.S,v 1.9 2000/07/25 20:15:40 mycroft 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.
 */

#include <machine/asm.h>

#include "SYS.h"

        .globl  __curbrk
        .globl  _end

        .data
        .align  8
__minbrk:
        .xword  _end                    /* lower brk limit; also for gmon code */
        END(__minbrk)
        OTYPE(__minbrk)
        .text

ENTRY_NB(brk)
#ifdef __PIC__
        PIC_PROLOGUE(%o5, %o4)
        set     __minbrk, %o4
        ldx     [%o5 + %o4], %o4
        ldx     [%o4], %o1              /* %o1 = minbrk */
        cmp     %o1, %o0                /* if (minbrk > %o0) */
        movgu   %xcc, %o1, %o0          /*      %o0 = minbrk */
        mov     %o0, %o2                /* save argument to syscall */
        mov     SYS_break, %g1
99:     t       ST_SYSCALL
        PINSYSCALL(SYS_break, 99b)
        set     __curbrk, %o3
        bcc,a,pt        %icc, 1f
         ldx    [%o5 + %o3], %o4
        ERROR()
1:
        retl                            /* success, return 0 & record new break */
         stx    %o2, [%o4]
#else
        sethi   %hi(__minbrk), %o1      /* %o1 = minbrk */
        ldx     [%o1 + %lo(__minbrk)], %o1
        cmp     %o1, %o0                /* if (minbrk > %o0) */
        movgu   %xcc, %o1, %o0          /*      %o0 = minbrk */
        mov     %o0, %o2                /* save argument to syscall */
        mov     SYS_break, %g1
98:     t       ST_SYSCALL
        PINSYSCALL(SYS_break, 98b)
        bcc,a,pt        %icc,1f
         sethi  %hi(__curbrk), %g1
        ERROR()
1:
        retl                            /* success, return 0 & record new break */
         stx    %o2, [%g1 + %lo(__curbrk)]
#endif
END(brk)
        .weak   brk