/*      $NetBSD: brk.S,v 1.6 2023/05/07 12:41:47 skrll Exp $    */

/*-
 * Copyright (c) 2014 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Matt Thomas of 3am Software Foundry.
 *
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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 "SYS.h"

#if defined(LIBC_SCCS) && !defined(lint)
        RCSID("$NetBSD: brk.S,v 1.6 2023/05/07 12:41:47 skrll Exp $")
#endif /* LIBC_SCCS and not lint */

        .hidden _C_LABEL(__minbrk)
        .hidden _C_LABEL(__curbrk)
        .globl  _C_LABEL(__minbrk)
        .globl  _C_LABEL(__curbrk)
        .globl  _C_LABEL(_end)

#ifdef WEAK_ALIAS
WEAK_ALIAS(brk, _brk)
#endif

        .data
        .p2align        PTR_SCALESHIFT
_C_LABEL(__minbrk):
        PTR_WORD        _C_LABEL(_end)
_C_LABEL(__curbrk):
        PTR_WORD        _C_LABEL(_end)

        .text

ENTRY(_brk)
        lla     t1, _C_LABEL(__minbrk)
        PTR_L   t5, 0(t1)
        bgeu    a0, t5, 1f
        mv      a0, t5          # dont allow break < minbrk
1:
        mv      t5, a0
        SYSTRAP(break)
        JUMP_TO_CERROR()                                /* error */
        PTR_S   t5, __SIZEOF_POINTER__(t1)              /* success */
        mv      a0, zero
        ret
END(_brk)