Index: kernel/generic/include/proc/thread.h
===================================================================
--- kernel/generic/include/proc/thread.h	(revision 40eab9fdcc5233a31ae07d23360a0b5fc2e5c701)
+++ kernel/generic/include/proc/thread.h	(revision 23f36a3cb9c57838fb51caaf810dcd9e271bfb86)
@@ -190,4 +190,10 @@
 extern void thread_interrupt(thread_t *);
 
+enum sleep_state {
+	SLEEP_INITIAL,
+	SLEEP_ASLEEP,
+	SLEEP_WOKE,
+};
+
 typedef enum {
 	THREAD_OK,