Index: kernel/arch/amd64/include/types.h
===================================================================
--- kernel/arch/amd64/include/types.h	(revision f2451459eff17f8a5c730a385925d2af36865089)
+++ kernel/arch/amd64/include/types.h	(revision 6da1013f00030b5dcedc878f40a0e6242a8d3282)
@@ -27,5 +27,5 @@
  */
 
-/** @addtogroup amd64	
+/** @addtogroup amd64
  * @{
  */
@@ -59,4 +59,7 @@
 
 typedef uintptr_t ioport_t;
+
+typedef struct {
+} fncptr_t;
 
 /**< Formats for uintptr_t, size_t, count_t and index_t */