Index: src/time/clock.c
===================================================================
--- src/time/clock.c	(revision 43114c515872442297f5b1b8a327743ef24c825a)
+++ src/time/clock.c	(revision 673104e55052fd9a0ddb2b6c2cc8b47a15e3f204)
@@ -44,6 +44,10 @@
 #endif
 
-/*
- * Clock is called from an interrupt and is cpu_priority_high()'d.
+/** Clock routine
+ *
+ * Clock routine executed from clock interrupt handler
+ * (assuming cpu_priority_high()). Runs expired timeouts
+ * and preemptive scheduling.
+ *
  */
 void clock(void)