diff --git a/Source/system/uart.c b/Source/system/uart.c
--- a/Source/system/uart.c
+++ b/Source/system/uart.c
@@ -1,3 +1,7 @@
+//
+// uart: configure and initialize GPS uart
+//
+
 #include "stm32f0xx_hal.h"
 
 #include "system/uart.h"