diff --git a/desmume/src/gtk/dTool.h b/desmume/src/gtk/dTool.h
new file mode 100644
index 000000000..24479dcd1
--- /dev/null
+++ b/desmume/src/gtk/dTool.h
@@ -0,0 +1,23 @@
+#ifndef __DTOOL_H__ 
+#define __DTOOL_H__
+
+#include <stdio.h>
+#define DTOOL_LOG(...) fprintf(stderr, __VA_ARGS__);
+
+#include "../types.h"
+#include "../nds/interrupts.h"
+
+typedef void (*dTool_openFn)();
+typedef void (*dTool_updateFn)();
+typedef void (*dTool_closeFn)();
+
+typedef struct
+{
+	const char name[64];
+	dTool_openFn open;
+	dTool_updateFn update;
+	dTool_closeFn close;
+	
+} dTool_t;
+
+#endif /*__DTOOL_H__*/
diff --git a/desmume/src/gtk/tools/ioregsView.h b/desmume/src/gtk/tools/ioregsView.h
new file mode 100644
index 000000000..b36dd3707
--- /dev/null
+++ b/desmume/src/gtk/tools/ioregsView.h
@@ -0,0 +1,9 @@
+#ifndef __IOREGSVIEW_H__
+#define __IOREGSVIEW_H__
+
+#include "../dTool.h"
+
+extern dTool_t dTool_ioregsView;
+
+#endif /*__IOREGSVIEW_H__*/
+