#include <esp_rom_sys.h>

void app_main() {
  volatile uint32_t* gpio_enable = (volatile uint32_t*)0x3FF44020;
  volatile uint32_t* gpio_out = (volatile uint32_t*)0x3FF44004;
  while(1) {
    *gpio_enable |= (1 << 2);
    *gpio_out ^= (1 << 2);
    esp_rom_delay_us(1000000);
  }
}