#include <stdint.h>

#include "isr_vector.h"
#include "ch573/gpio.h"

#define GPIO_PORT_A ch573_gpio__gpio_port_a
#define GPIO_PORT CH573_GPIO__GPIO_PORT_T_INTF

/*
 * Function which delays for a bit.
 */
void delay(void);

void main(void);

uint32_t collatz(uint32_t n)
{
  uint32_t c = 0;

  while (n > 1) {
    if (n % 2 == 0) {
      n /= 2;
    } else {
      n = n * 3 + 1;
    }
    c++;
  }

  return c;
}

void blink_n(int n)
{
  uint32_t bit = 1 << 8;
  while (n > 0) {
    GPIO_PORT.out.set(GPIO_PORT_A, OFF, 8);
    delay();
    GPIO_PORT.out.set(GPIO_PORT_A, ON, 8);
    delay();
    --n;
  }
}

void delay(void)
{
  for (volatile uint32_t i = 0; i < 10000; ++i) {
    asm volatile("");
  }
}

volatile uint32_t deadbeef = 0xdeadbeef;

// Memory-mapped address of the data values in flash.
extern uint32_t DATA_VALUES_IN_FLASH;

// Where the data is located in sram.
extern uint32_t DATA_SEGMENT_START;
extern uint32_t DATA_SEGMENT_STOP;

/* Main routine. This is called on_reset once everything else has been set up.
 */
void main(void)
{
  GPIO_PORT.dir.set(GPIO_PORT_A, DIR_OUT, 8);
  GPIO_PORT.pd_drv.set(GPIO_PORT_A, PD_DRV_OPEN_DRAIN, 8);

  for (;;) {
    if (deadbeef == 0xdeadbeef) {
      GPIO_PORT.out.set(GPIO_PORT_A, ON, 8);
    }
    delay();
    delay();
    delay();
    GPIO_PORT.out.set(GPIO_PORT_A, OFF, 8);
    delay();
  }
}

IRQ(systick) {
  collatz(5);
}

IRQ(exc) {}

IRQ(nmi) {}