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/*

 * Copyright (c) 2003  Red Hat, Inc. All rights reserved.

 *

 * This copyrighted material is made available to anyone wishing to use, modify,

 * copy, or redistribute it subject to the terms and conditions of the BSD

 * License.  This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY expressed or implied, including the implied

 * warranties of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  A copy

 * of this license is available at http://www.opensource.org/licenses. Any

 * Red Hat trademarks that are incorporated in the source code or documentation

 * are not subject to the BSD License and may only be used or replicated with

 * the express permission of Red Hat, Inc.

 */

#include <errno.h>

extern int __heap __far;      /* beginning of heap */

extern int __heap_end __far;  /* if at address 0, use stack pointer as limit */

static char *the_break = (char *)(& __heap);

int

is_addr_0 (int address)

{

  return address ? 0 : 1;

}

void *

sbrk(int inc)

{

  char *current_heap_limit = (char *) (& __heap_end);

  /* is_addr_0 avoids optimizing out this block.  */

  if (is_addr_0 ((int) current_heap_limit))

    {

      int something;

      int margin = 4096;

      current_heap_limit = (char *) (& something) - margin;

    }

  if ((the_break + inc) < current_heap_limit)

    {

      void *rv = (void *) the_break;

      the_break += inc;

      return rv;

    }

  else

    {

      errno = ENOMEM;

      return (void *) -1;

    }

}

int

brk (void *ptr)

{

  the_break = ptr;

  return 0;

}