/**
*****************************************************************************
**
**  File        : sysmem.c
**
**  Author	    : Ac6
**
**  Abstract    : System Workbench Minimal System Memory calls file
**
** 		          For more information about which c-functions
**                need which of these lowlevel functions
**                please consult the Newlib libc-manual
**
**  Environment : System Workbench for MCU
**
**  Distribution: The file is distributed as is, without any warranty
**                of any kind.
**
**  (c)Copyright System Workbench for MCU.
**  You may use this file as-is or modify it according to the needs of your
**  project. Distribution of this file (unmodified or modified) is not
**  permitted. System Workbench for MCU permit registered System Workbench(R) users the
**  rights to distribute the assembled, compiled & linked contents of this
**  file as part of an application binary file, provided that it is built
**  using the System Workbench for MCU toolchain.
**
*****************************************************************************
*/

/* Includes */
/*---------------------------------------------------------------------------*/
#include <errno.h>
#include <stdio.h>
/*---------------------------------------------------------------------------*/
/* Variables */
extern int errno;
register char * stack_ptr asm("sp");
/*---------------------------------------------------------------------------*/
/* Functions */

/*---------------------------------------------------------------------------*/
/**
 _sbrk
 Increase program data space. Malloc and related functions depend on this
**/
caddr_t _sbrk(int incr)
{
  extern char end asm("end");
  static char *heap_end;
  char *prev_heap_end;

  if (heap_end == 0) {
    heap_end = &end;
  }

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

  heap_end += incr;

  return (caddr_t) prev_heap_end;
}
/*---------------------------------------------------------------------------*/