+#if HAS_SERIAL_1
+
+struct ao_stm_usart ao_stm_usart1;
+
+void stm_usart1_isr(void) { ao_usart_isr(&ao_stm_usart1, USE_SERIAL_1_STDIN); }
+
+char
+ao_serial1_getchar(void)
+{
+ return ao_usart_getchar(&ao_stm_usart1);
+}
+
+void
+ao_serial1_putchar(char c)
+{
+ ao_usart_putchar(&ao_stm_usart1, c);
+}
+
+int
+_ao_serial1_pollchar(void)
+{
+ return _ao_usart_pollchar(&ao_stm_usart1);
+}
+
+void
+ao_serial1_set_speed(uint8_t speed)
+{
+ ao_usart_set_speed(&ao_stm_usart1, speed);
+}
+#endif /* HAS_SERIAL_1 */
+
+#if HAS_SERIAL_2
+
+struct ao_stm_usart ao_stm_usart2;
+
+void stm_usart2_isr(void) { ao_usart_isr(&ao_stm_usart2, USE_SERIAL_2_STDIN); }
+
+char
+ao_serial2_getchar(void)
+{
+ return ao_usart_getchar(&ao_stm_usart2);
+}
+
+void
+ao_serial2_putchar(char c)
+{
+ ao_usart_putchar(&ao_stm_usart2, c);
+}
+
+int
+_ao_serial2_pollchar(void)
+{
+ return _ao_usart_pollchar(&ao_stm_usart2);
+}
+
+void
+ao_serial2_set_speed(uint8_t speed)
+{
+ ao_usart_set_speed(&ao_stm_usart2, speed);
+}
+#endif /* HAS_SERIAL_2 */
+
+#if HAS_SERIAL_3
+
+struct ao_stm_usart ao_stm_usart3;
+
+void stm_usart3_isr(void) { ao_usart_isr(&ao_stm_usart3, USE_SERIAL_2_STDIN); }
+
+char
+ao_serial3_getchar(void)
+{
+ return ao_usart_getchar(&ao_stm_usart3);
+}
+
+void
+ao_serial3_putchar(char c)
+{
+ ao_usart_putchar(&ao_stm_usart3, c);
+}
+
+int
+_ao_serial3_pollchar(void)
+{
+ return _ao_usart_pollchar(&ao_stm_usart3);
+}
+
+void
+ao_serial3_set_speed(uint8_t speed)
+{
+ ao_usart_set_speed(&ao_stm_usart3, speed);
+}
+#endif /* HAS_SERIAL_3 */
+
+void
+ao_serial_init(void)
+{
+#if HAS_SERIAL_1
+ /*
+ * TX RX
+ * PA9 PA10
+ * PB6 PB7 *
+ */
+
+#if SERIAL_1_PA9_PA10
+ stm_rcc.ahbenr |= (1 << STM_RCC_AHBENR_GPIOAEN);
+
+ stm_afr_set(&stm_gpioa, 9, STM_AFR_AF7);
+ stm_afr_set(&stm_gpioa, 10, STM_AFR_AF7);
+#else
+#if SERIAL_1_PB6_PB7
+ stm_rcc.ahbenr |= (1 << STM_RCC_AHBENR_GPIOBEN);
+
+ stm_afr_set(&stm_gpiob, 6, STM_AFR_AF7);
+ stm_afr_set(&stm_gpiob, 7, STM_AFR_AF7);
+#else
+#error "No SERIAL_1 port configuration specified"