From 7086e5f9e9a13347524a7929bd13118a7916fa2f Mon Sep 17 00:00:00 2001
From: Imbus <>
Date: Wed, 16 Jul 2025 18:00:08 +0200
Subject: [PATCH] uart

---
 main.c | 10 +---------
 uart.c | 17 +++++++++--------
 2 files changed, 10 insertions(+), 17 deletions(-)

diff --git a/main.c b/main.c
index 8899a99..30a3680 100644
--- a/main.c
+++ b/main.c
@@ -16,7 +16,6 @@ static void gpio_setup(void) {
     /* Setup GPIO6 and 7 (in GPIO port A) for LED use. */
     gpio_set_mode(GPIOC, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_PUSHPULL, GPIO12);
 }
-
 static void clock_setup(void) {
     rcc_clock_setup_pll(&rcc_hse_configs[RCC_CLOCK_HSE8_72MHZ]);
 
@@ -37,14 +36,7 @@ int main(void) {
     sys_tick_setup();
     usart_setup();
 
-    usart_send_blocking(USART1, 'H');
-    usart_send_blocking(USART1, 'e');
-    usart_send_blocking(USART1, 'l');
-    usart_send_blocking(USART1, 'l');
-    usart_send_blocking(USART1, 'o');
-    usart_send_blocking(USART1, '\n');
-
-    printf("Well hello");
+    printf("Printf is working!\n");
 
     gpio_clear(GPIOC, GPIO13);
     gpio_set(GPIOC, GPIO13);
diff --git a/uart.c b/uart.c
index 30dca19..369ad15 100644
--- a/uart.c
+++ b/uart.c
@@ -5,6 +5,7 @@
 #include <libopencm3/stm32/rcc.h>
 #include <libopencm3/stm32/usart.h>
 #include <stdio.h>
+#include <unistd.h>
 
 int _write(int file, char *ptr, int len);
 
@@ -12,7 +13,6 @@ void usart_setup(void) {
     /* Setup GPIO pin GPIO_USART1_RE_TX on GPIO port B for transmit. */
     gpio_set_mode(GPIOA, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_ALTFN_PUSHPULL, GPIO_USART1_TX);
 
-    /* Setup UART parameters. */
     usart_set_baudrate(USART1, 115200);
     usart_set_databits(USART1, 8);
     usart_set_stopbits(USART1, USART_STOPBITS_1);
@@ -20,18 +20,19 @@ void usart_setup(void) {
     usart_set_flow_control(USART1, USART_FLOWCONTROL_NONE);
     usart_set_mode(USART1, USART_MODE_TX);
 
-    /* Finally enable the USART. */
     usart_enable(USART1);
 }
 
 int _write(int file, char *ptr, int len) {
-    int i;
-
-    if (file == 1) {
-        for (i = 0; i < len; i++) usart_send_blocking(USART1, ptr[i]);
-        return i;
+    if (file == STDOUT_FILENO || file == STDERR_FILENO) {
+        for (int i = 0; i < len; i++) {
+            if (ptr[i] == '\n') {
+                usart_send_blocking(USART1, '\r');
+            }
+            usart_send_blocking(USART1, ptr[i]);
+        }
+        return len;
     }
-
     errno = EIO;
     return -1;
 }