#define SERIAL Serial

const byte ONBOARD_LED = 25;


const volatile uint32_t* GPIO0_CTRL       = (uint32_t*)(0x40014004);
const volatile uint32_t* GPIO8_CTRL       = (uint32_t*)(0x40014044);
volatile uint32_t* const GPIO25_CTRL      = (uint32_t*)(0x400140CC);

volatile uint32_t* const REG_GPIO_OUT     = (uint32_t*)(0xd0000010);
volatile uint32_t* const REG_GPIO_OUT_SET = (uint32_t*)(0xd0000014);
volatile uint32_t* const REG_GPIO_OUT_CLR = (uint32_t*)(0xd0000018);
volatile uint32_t* const REG_GPIO_OUT_XOR = (uint32_t*)(0xd000001C);


volatile uint32_t* const PAD_GPIO25       = (uint32_t*)(0x4001c068);


//#define MEM32(address) (*(volatile uin32_t*)(address))

void setup() {
  SERIAL.begin(115200);
  SERIAL.println("Starting .... ");

  //pinMode(ONBOARD_LED, OUTPUT);
  //for (int i=8; i<16; i++ ) {
  //  pinMode(i, OUTPUT);
  //}

  printf( "GPIO25_CTRL %02X\n", *GPIO25_CTRL);
  printf( "PAD_GPIO25  %02X\n", *PAD_GPIO25);
  *GPIO25_CTRL = 0x05;
  *PAD_GPIO25 = 0x72;
  printf( "GPIO25_CTRL %02X\n", *GPIO25_CTRL);
  printf( "PAD_GPIO25  %02X\n", *PAD_GPIO25);

  pinMode (ONBOARD_LED, OUTPUT);
  printf( "PAD_GPIO25  %02X\n", *PAD_GPIO25);

}

static int sum = 0;
void loop() {
  for ( int i=0; i< 5000000; i++) {
    sum+= sum * sum + 1;
  }
  auto bt = bit(25);
  *REG_GPIO_OUT_XOR = bt;
  SERIAL.println(sum);

}