/**
*****************************************************************************
**
**  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;
}