#include <stdint.h>
void app_main(void) {
  volatile uint32_t *gpio_enable = (volatile uint32_t *)0x3FF44020;
  volatile uint32_t *gpio_out    = (volatile uint32_t *)0x3FF44004;
  *gpio_enable |= (1 << 2);  // GPIO2 as output
  while (1) {
    *gpio_out |= (1 << 2);        // HIGH
  }
}