Use USART2

build/main.i

@@ -2252,6 +2252,56 @@ struct timer {
 void tim4_init(void);
 void tim4_start(void);
 # 9 "src/main.c" 2
+# 1 "src/usart.h" 1
+
+#define USART_H_ 
+
+
+
+struct usart {
+  volatile uint32_t SR;
+  volatile uint32_t DR;
+  volatile uint32_t BRR;
+  volatile uint32_t CR1;
+  volatile uint32_t CR2;
+  volatile uint32_t CR3;
+  volatile uint32_t GTPR;
+};
+
+#define USART2_BASE_ADDR (0x40004400U)
+#define USART2 ((struct usart *) USART2_BASE_ADDR)
+
+
+
+#define USART_SR_TC_BIT 6
+#define USART_SR_TC_COMPLETED (1 << USART_SR_TC_BIT)
+
+
+
+#define USART_CR1_UE_BIT 13
+#define USART_CR1_UE_ENABLE (1 << USART_CR1_UE_BIT)
+
+
+#define USART_CR1_TE_BIT 3
+#define USART_CR1_TE_ENABLE (1 << USART_CR1_TE_BIT)
+
+
+#define USART_CR1_RE_BIT 2
+#define USART_CR1_RE_ENABLE (1 << USART_CR1_RE_BIT)
+
+
+#define USART_BRR_MANTISSA_BIT 4
+#define USART_BRR_MANTISSA_MASK (0b111111111111)
+
+#define USART_BRR_FRACTION_BIT 0
+#define USART_BRR_FRACTION_MASK (0b111)
+
+void usart2_init(void);
+void usart2_start(void);
+
+void usart2_write_byte(uint8_t byte);
+void usart2_write(char *buf);
+# 10 "src/main.c" 2
 
 #define exit 42
 
@@ -2321,8 +2371,10 @@ static void system_clock_init(void) {
 int main(void) {
   (void) system_clock_init();
   (void) tim4_init();
+  (void) usart2_init();
 
   (void) tim4_start();
+  (void) usart2_start();
 
   uint16_t led = (((('C') - 'A') << 8) | 13);
   ((struct rcc *) (0x40023800U))->AHB1ENR |= (1 << (led >> 8));
@@ -2330,19 +2382,21 @@ int main(void) {
 
   uint16_t counter = ((struct timer *) (0x40000800U))->CNT;
   
-# 86 "src/main.c" 3 4
+# 89 "src/main.c" 3 4
  _Bool 
-# 86 "src/main.c"
+# 89 "src/main.c"
       led_on = 
-# 86 "src/main.c" 3 4
+# 89 "src/main.c" 3 4
                ((_Bool)+0u)
-# 86 "src/main.c"
+# 89 "src/main.c"
                     ;
   while(1) {
  if ((((struct timer *) (0x40000800U))->CNT - counter) >= 250) {
   led_on = !led_on;
   gpio_write(led, led_on);
 
+  usart2_write("hello, world!\n");
+
   counter = ((struct timer *) (0x40000800U))->CNT;
  }
   };