Rewrite logging system and sync state with clients

src/common.c

@@ -1 +1,29 @@
-void *TODO;
+#include "common.h"
+#include "serial.h"
+
+#define PREFIX_ERROR(fmt) "Error:" fmt
+
+static bool state;
+
+void Info(const char *fmt, ...)
+{
+	va_list args;
+
+	va_start(args, fmt);
+	USART_Print(state, "", fmt, args);
+	va_end(args);
+}
+
+void Error(const char *fmt, ...)
+{
+	va_list args;
+
+	va_start(args, fmt);
+	USART_Print(state, "Error: ", fmt, args);
+	va_end(args);
+}
+
+void SetStateFlag(bool is_running)
+{
+	state = is_running;
+}