CPU testing

lib/dbg.c

@@ -0,0 +1,21 @@
+#include <dbg.h>
+#include <bus.h>
+
+static char dbg_msg[1024] = {0};
+static int msg_size = 0;
+
+void dbg_update(){
+    if (bus_read(0xFF02) == 0x81) {
+        char c = bus_read(0xFF01);
+
+        dbg_msg[msg_size++] = c;
+
+        bus_write(0xFF02, 0);
+    }
+}
+
+void dbg_print(){
+    if(dbg_msg[0]) {
+        printf("DBG: %s\n", dbg_msg);
+    }
+}