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/* sbrk.c -- allocate memory dynamically.

 *

 * Copyright (c) 1995,1996 Cygnus Support

 *

 * The authors hereby grant permission to use, copy, modify, distribute,

 * and license this software and its documentation for any purpose, provided

 * that existing copyright notices are retained in all copies and that this

 * notice is included verbatim in any distributions. No written agreement,

 * license, or royalty fee is required for any of the authorized uses.

 * Modifications to this software may be copyrighted by their authors

 * and need not follow the licensing terms described here, provided that

 * the new terms are clearly indicated on the first page of each file where

 * they apply.

 */

#include <errno.h>

#include "glue.h"

/* just in case, most boards have at least some memory */

#ifndef RAMSIZE

#  define RAMSIZE             (caddr_t)0x100000

#endif

char *heap_ptr;

/*

 * sbrk -- changes heap size size. Get nbytes more

 *         RAM. We just increment a pointer in what's

 *         left of memory on the board.

 */

char *

sbrk (nbytes)

     int nbytes;

{

  char        *base;

  if (!heap_ptr)

    heap_ptr = (char *)&_end;

  base = heap_ptr;

  heap_ptr += nbytes;

  return base;

/* FIXME: We really want to make sure we don't run out of RAM, but this

 *       isn't very portable.

 */

#if 0

  if ((RAMSIZE - heap_ptr - nbytes) >= 0) {

    base = heap_ptr;

    heap_ptr += nbytes;

    return (base);

  } else {

    errno = ENOMEM;

    return ((char *)-1);

  }

#endif

}