/*      $OpenBSD: sbrk.S,v 1.13 2022/12/08 01:25:43 guenther Exp $      */
/*      $NetBSD: sbrk.S,v 1.7 2003/08/07 16:42:05 agc Exp $     */

/*-
 * Copyright (c) 1990 The Regents of the University of California.
 * All rights reserved.
 *
 * 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: @(#)sbrk.s        5.1 (Berkeley) 4/23/90
 */

#include "SYS.h"

        .globl  _end

        .data
        .align  2
        .globl  __curbrk
        .type   __curbrk,#object
        .hidden __curbrk
__curbrk:
        .word   _end
        END(__curbrk)

/*
 * Change the data segment size
 */
ENTRY_NB(sbrk)
#ifdef __PIC__
        /* Setup the GOT */
        ldr     r3, .Lgot
        ldr     r2, .Lcurbrk
.L1:
        add     r3, pc, r3
        ldr     r2, [r3, r2]
#else
        ldr     r2, .Lcurbrk
#endif
        /* Get the current brk address */
        ldr     r1, [r2]

        /* Calculate new value */
        mov     r3, r0
        add     r0, r0, r1
        SYSTRAP(break)
        bcs     CERROR

        /* Store new curbrk value */
        ldr     r0, [r2]
        add     r1, r0, r3
        str     r1, [r2]

        /* Return old curbrk value */
        mov     r15, r14

        .align  2
#ifdef __PIC__
.Lgot:
        .word   _GLOBAL_OFFSET_TABLE_ - (.L1+8)
#endif
.Lcurbrk:
        .word   PIC_SYM(__curbrk, GOT)
END(sbrk)
        .weak   sbrk