STM32F429I change debug port, from UART4 to USART1

f9_usart1

diff --git a/board/discoveryf4/board.c b/board/discoveryf4/board.c
index 5098469..4277cf4 100644
--- a/board/discoveryf4/board.c
+++ b/board/discoveryf4/board.c
@@ -7,26 +7,26 @@
 #include <platform/stm32f4/usart.h>
 
 struct usart_dev console_uart = {
-	.u_num = 4,
+	.u_num = 1,
 	.baud = 115200,
-	.base = UART4_BASE,
-	.rcc_apbenr = RCC_UART4_APBENR,
-	.rcc_reset = RCC_APB1RSTR_USART4RST,
+	.base = USART1_BASE,
+	.rcc_apbenr = RCC_USART1_APBENR,
+	.rcc_reset = RCC_APB2RSTR_USART1RST,
 	.tx = {
 		.port = GPIOA,
-		.pin = 0,
+		.pin = 9,
 		.pupd = GPIO_PUPDR_NONE,
 		.type = GPIO_MODER_ALT,
-		.func = af_uart4,
+		.func = af_usart1,
 		.o_type = GPIO_OTYPER_PP,
 		.speed = GPIO_OSPEEDR_50M,
 	},
 	.rx = {
 		.port = GPIOA,
-		.pin = 1,
+		.pin = 10,
 		.pupd = GPIO_PUPDR_NONE,
 		.type = GPIO_MODER_ALT,
-		.func = af_uart4,
+		.func = af_usart1,
 		.o_type = GPIO_OTYPER_PP,
 		.speed = GPIO_OSPEEDR_50M,
 	},
diff --git a/board/discoveryf4/board.h b/board/discoveryf4/board.h
index 74221ff..7b9d92a 100644
--- a/board/discoveryf4/board.h
+++ b/board/discoveryf4/board.h
@@ -14,8 +14,8 @@
 
 extern struct usart_dev console_uart;
 #define BOARD_UART_DEVICE \
-	UART4_IRQn
+	USART1_IRQn
 
-#define BOARD_UART_HANDLER	UART4_HANDLER
+#define BOARD_UART_HANDLER	USART1_HANDLER
 
 #endif	/* DISCOVERYF4_BOARD_H_ */
diff --git a/platform/stm32f4/usart.c b/platform/stm32f4/usart.c
index deadf05..02c1853 100644
--- a/platform/stm32f4/usart.c
+++ b/platform/stm32f4/usart.c
@@ -25,13 +25,18 @@ struct usart_regs {
 
 /* Calculates the value for the USART_BRR */
 /* TODO: Need more precise algorithm */
-static int16_t usart_baud(uint32_t baud)
+static int16_t usart_baud(uint32_t base, uint32_t baud)
 {
        uint16_t mantissa;
        uint16_t fraction;
 
-       mantissa = (42000000) / (16 *  baud);
-       fraction = (42000000 / baud) % 16;
+       if ((base == USART1_BASE) || (base == USART6_BASE)) {
+               mantissa = (42000000*2) / (16 *  baud);
+               fraction = ((42000000*2) / baud) % 16;
+       } else {
+               mantissa = (42000000) / (16 *  baud);
+               fraction = (42000000 / baud) % 16;
+       }
 
        return (mantissa << 4) | fraction;
 }
@@ -110,7 +115,7 @@ void usart_init(struct usart_dev *usart)
        uregs->CR2 &= ~(3 << 12);
 
        /* Set baud rate */
-       uregs->BRR = usart_baud(usart->baud);
+       uregs->BRR = usart_baud(usart->base, usart->baud);
 
        /* Enable reciever and transmitter */
        uregs->CR1 |= (USART_CR1_RE | USART_CR1_TE);