--- src/sys/sys/kobj.h	2006/05/20 02:42:13	1.10
+++ src/sys/sys/kobj.h	2007/10/03 18:58:20	1.11
@@ -127,6 +127,16 @@ struct kobj_class classvar = {				\
 }
 
 /*
+ * Define a class with no base classes using the named structure
+ * as an extension of the kobj_class structure.
+ */
+#define DEFINE_CLASS_EXT(name, classvar, methods, size, extname)	\
+							\
+struct extname classvar = {				\
+	#name, methods, size, NULL, 0, NULL		\
+}
+
+/*
  * Define a class inheriting a single base class. Use like this:
  *
  * DEFINE_CLASS1(foo, foo_class, foo_methods, sizeof(foo_softc),