#include <stdint.h>

#define RCC_AHB2ENR (*(uint32_t*)0x4002104C)
#define RCC_AHB2ENR (*(uint32_t*)0x40021058)
#define GPIOA_MODER (*(uint32_t*)0x48000000)
#define GPIOA_AFRL (*(uint32_t*)0x48000020)
#define USART2_CR1 (*(uint32_t*)0x40004400)
#define USART2_BRR (*(uint32_t*)0x4000440C)
#define USART2_RDR (*(uint32_t*)0x40004424)
#define USART2_TDR (*(uint32_t*)0x40004428)
#define USART_ISR (*(uint32_t*)0x4000441C)


void GPIO_Init()
{
  GPIOA_MODER &= ~(3 << 4);
  GPIOA_MODER &= ~(3 << 6);

  GPIOA_MODER |= ~(2 << 4);
  GPIOA_MODER |= ~(2 << 6);

  GPIOA_AFRL &= ~(15 << 8);
  GPIOA_AFRL &= ~(15 << 12);

  GPIOA_AFRL |= (7 << 8);
  GPIOA_AFRL |= (7 << 12);
}

void RCC_Init()
{
  RCC_AHB2ENR |= (1 << 0);
  RCC_APB1ENR |= (1 << 17);
}

void UART_Init()
{
  USART2_BRR = (16000000/115200);
  USART2_CR1 |= (1 << 0);
  USART2_CR1 |= (1 << 2);
  USART2_CR1 |= (1 << 3);
}

int main(void)
{
  RCC_Init();
  GPIO_Init();


}