Index: sys/kern/kern_clocksource.c
===================================================================
--- sys/kern/kern_clocksource.c
+++ sys/kern/kern_clocksource.c
@@ -665,6 +665,7 @@
 	statperiod = SBT_1S / stathz;
 	profperiod = SBT_1S / profhz;
 	ET_LOCK();
+	printf("CALLOUT: time when starting: %lx\n", sbinuptime());
 	configtimer(1);
 	ET_UNLOCK();
 }
Index: sys/kern/kern_timeout.c
===================================================================
--- sys/kern/kern_timeout.c
+++ sys/kern/kern_timeout.c
@@ -416,6 +416,31 @@
 }
 SYSINIT(start_softclock, SI_SUB_SOFTINTR, SI_ORDER_FIRST, start_softclock, NULL);
 
+static void
+test_callout(void *arg)
+{
+
+	printf("CALLOUT: %s fired at %lx\n", (const char *)arg, sbinuptime());
+}
+
+static void
+test_callouts(void *dummy)
+{
+	static struct callout c1, c2, c4, c10;
+
+	printf("CALLOUT: uptime at test start: %lx\n", sbinuptime());
+
+	callout_init(&c1, 1);
+	callout_init(&c2, 1);
+	callout_init(&c4, 1);
+	callout_init(&c10, 1);
+	callout_reset(&c1, hz, test_callout, "1 second");
+	callout_reset(&c2, 2 * hz, test_callout, "2 second");
+	callout_reset(&c4, 4 * hz, test_callout, "4 second");
+	callout_reset(&c10, 10 * hz, test_callout, "10 second");
+}
+SYSINIT(test_callouts, SI_SUB_SOFTINTR, SI_ORDER_SECOND, test_callouts, NULL);
+
 #define	CC_HASH_SHIFT	8
 
 static inline u_int
@@ -981,6 +1006,8 @@
 		spinlock_exit();
 #endif
 #endif
+		if (cold && to_sbt == 0)
+			to_sbt = sbinuptime();
 		if ((flags & C_HARDCLOCK) == 0)
 			to_sbt += tick_sbt;
 	} else
Index: sys/kern/subr_sleepqueue.c
===================================================================
--- sys/kern/subr_sleepqueue.c
+++ sys/kern/subr_sleepqueue.c
@@ -386,7 +386,7 @@
 	MPASS(TD_ON_SLEEPQ(td));
 	MPASS(td->td_sleepqueue == NULL);
 	MPASS(wchan != NULL);
-	if (cold)
+	if (cold && td == &thread0)
 		panic("timed sleep before timers are working");
 	KASSERT(td->td_sleeptimo == 0, ("td %d %p td_sleeptimo %jx",
 	    td->td_tid, td, (uintmax_t)td->td_sleeptimo));