Add logging functionality

Framing.h

@@ -106,6 +106,14 @@
   #define ERROR_MEMORY_LOW    0x05
   #define ERROR_MODEM_TIMEOUT 0x06
 
+  // Serial logging
+  #define LOG_MSG         0x2F
+
+  #define MSG_INFO        0x01
+  #define MSG_ERR         0x02
+  #define MSG_DBG         0x03
+  #define MSG_TRACE       0x04
+
   // Serial framing variables
   size_t frame_len;
   bool IN_FRAME = false;

Utilities.h

@@ -1712,4 +1712,24 @@ void unlock_rom() {
 	eeprom_erase();
 }
 
+void log_debug(const char* msg) {
+    serial_write(FEND);
+    serial_write(LOG_MSG);
+    serial_write(MSG_DBG);
+    for (int i = 0; i < strlen(msg); i++) {
+        escaped_serial_write(msg[i]);
+    }
+    serial_write(FEND);
+}
+
+void log_debug(char* msg) {
+    serial_write(FEND);
+    serial_write(LOG_MSG);
+    serial_write(MSG_DBG);
+    for (int i = 0; i < strlen(msg); i++) {
+        escaped_serial_write(msg[i]);
+    }
+    serial_write(FEND);
+}
+
 #include "src/misc/FIFOBuffer.h"