Subversion Repositories openrisc_2011-10-31

#include <_ansi.h>

#include <sys/types.h>

#include <sys/stat.h>

#include "regs.S"

extern char _end[];

/* FIXME: This is not ideal, since we do a get_mem_info() call for

   every sbrk() call. */

char *

sbrk (nbytes)

     int nbytes;

{

  static char *heap_ptr = _end;

  static char *heap_start = _end;

  char        *base;

  struct s_mem {

    unsigned int size;

    unsigned int icsize;

    unsigned int dcsize;

  } mem;

  unsigned int avail = 0;

  /* The sizeof (s_mem.size) must be 4 bytes.  The compiler should be

     able to eliminate this check */

  if (sizeof (unsigned int) != 4)

    return (char *)-1;

  get_mem_info(&mem);

  /* NOTE: The value returned from the get_mem_info call is the amount

     of memory, and not the address of the (last byte + 1) */

  if (((size_t)heap_ptr >= heap_start) && ((size_t)heap_ptr < (heap_start + mem.size))) {

    avail = (heap_start + mem.size) - (size_t)heap_ptr;

    base = heap_ptr;

  } /* else will fail since "nbytes" will be greater than zeroed "avail" value */

  if ((nbytes > avail) || (heap_ptr + nbytes < _end))

   base = (char *)-1;

  else

   heap_ptr += nbytes;

  return base;

}