Subversion Repositories openrisc_2011-10-31

/*

 * cf-sbrk.c --

 *

 * Copyright (c) 2006 CodeSourcery Inc

 *

 * 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>

/*

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

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

 *         left of memory on the board.

 */

extern char __end[] __attribute__ ((aligned (4)));

/* End of heap, if non NULL.  */

extern void *__heap_limit;

void *

sbrk (int nbytes)

{

  static char *heap = __end;

  char *end = __heap_limit;

  char *base = heap;

  char *new_heap = heap + nbytes;

  if (!end)

    {

      /* Use sp - 256 as the heap limit.  */

      __asm__ __volatile__ ("move.l %/sp,%0" : "=r"(end));

      end -= 256;

    }

  if (nbytes < 0 || (long)(end - new_heap) < 0)

    {

      errno = ENOMEM;

      return (void *)-1;

    }

  heap = new_heap;

  return base;

}