/*
 * Copyright (c) 2015, Freescale Semiconductor, Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 * o Redistributions of source code must retain the above copyright notice, this list
 *   of conditions and the following disclaimer.
 *
 * o 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.
 *
 * o Neither the name of Freescale Semiconductor, Inc. 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 COPYRIGHT HOLDERS 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 COPYRIGHT HOLDER 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.
 */
#if defined(__GNUC__)
#include <stdio.h>
#include <errno.h>
#endif

#if defined(__GNUC__)
/*!
 * @brief Function to override ARMGCC default function _sbrk
 *
 * _sbrk is called by malloc. ARMGCC default _sbrk compares "SP" register and
 * heap end, if heap end is larger than "SP", then _sbrk returns error and
 * memory allocation failed. This function changes to compare __HeapLimit with
 * heap end.
 */
caddr_t _sbrk(int incr)
{
    extern char end __asm("end");
    extern char heap_limit __asm("__HeapLimit");
    static char *heap_end;
    char *prev_heap_end;

    if (heap_end == NULL)
        heap_end = &end;

    prev_heap_end = heap_end;

    if (heap_end + incr > &heap_limit)
    {
        errno = ENOMEM;
        return (caddr_t)-1;
    }

    heap_end += incr;

    return (caddr_t)prev_heap_end;
}
#endif
