include <stdio.h>
#include <stdlib.h>
#include<unistd.h>
#include<sys/types.h>
#include<sys/mman.h>
#include<fcntl.h>
#include<string.h>
#include<signal.h>
#include <sys/times.h>
#include <time.h>

struct sigaction osa;
#define DIOBASE 0xE8000000
static unsigned char _Stop = 0;


void
bypass_sigint (int sig_no)
{

  _Stop = 1;
  printf ("STOP CALLED. \n");
  
}



void
setupSIGInterupt ()
{

  struct sigaction sa, osa;
  memset (&sa, 0, sizeof (sa));
  sa.sa_handler = &bypass_sigint;
  sigaction (SIGINT, &sa, &osa);
}

int main (int argc, char **argv)
{
  setupSIGInterupt ();

  volatile unsigned int *PDATA;
  unsigned char *iostart;

  int fd = open ("/dev/mem", O_RDWR | O_SYNC);
  iostart =
    mmap (0, getpagesize (), PROT_READ | PROT_WRITE, MAP_SHARED, fd, DIOBASE);

  PDATA = (unsigned int *) (iostart + 0x04);

  unsigned short int diovalue = *PDATA; //only need 16 bits
  unsigned short int olddiovalue = diovalue;


  while(!_Stop)
  {
    diovalue = *PDATA;

    if(diovalue != olddiovalue)
    {
        olddiovalue = diovalue;
        printf("STATE CHANGE! %d\n", diovalue);

        if(diovalue ^ 0x55DC)
        {
          printf("Stop!\n");
        }
        else
        {
          printf("Execute!\n");
        }
    }
    usleep(5000);

  }

  return 0;
}