diff --git a/kernel/arch/x86_64/apic.c b/kernel/arch/x86_64/apic.c
index 725f8f4..2cce1c0 100644
--- a/kernel/arch/x86_64/apic.c
+++ b/kernel/arch/x86_64/apic.c
@@ -109,7 +109,7 @@ static void apic_timer_calibrate()
 	}
 
 	uint64_t avg = sum / (wait_ms * runs);
-	avg = (avg+100000) / 100000 * 100000;
+	avg = (avg + 100000) / 100000 * 100000;
 	curcpu()->md.lapic_ticks_per_ms = avg;
 	printk(LOG_DBG "apic timer: %ld ticks/ms\n",
 	       curcpu()->md.lapic_ticks_per_ms);
@@ -130,6 +130,9 @@ static int apic_timer_handler(IrqObj *obj, Context *ctx, void *private)
 
 void apic_arm(uint64_t delta_us)
 {
+#if 0
+	printk("next timer in %ld ms\n", delta_us / 1000);
+#endif
 	if (delta_us == 0) {
 		apic_write(APIC_REG_TIMER_INITIAL, 0);
 		return;
diff --git a/kernel/include/ivy-internal/sched.h b/kernel/include/ivy-internal/sched.h
index 95c4ec8..12019c3 100644
--- a/kernel/include/ivy-internal/sched.h
+++ b/kernel/include/ivy-internal/sched.h
@@ -1,5 +1,6 @@
 #pragma once
 
+#include "ivy/status.h"
 #include <sys/queue.h>
 #include "ivy/cpudata.h"
 #include "ivy/object.h"
@@ -16,6 +17,7 @@ void sched_preempt(CpuData *data);
 void sched_yield(Thread *thread, CpuData *data);
 
 void sched_unwait_thread(Thread *thread, int status, int boost);
-int sched_wait_thread(Thread *thread, int hastimeout);
+
+OsStatus sched_wait_thread(Thread *thread, int hastimeout);
 
 void sched_internal_ready(Thread *thread);
diff --git a/kernel/include/ivy/sched.h b/kernel/include/ivy/sched.h
index c98adc3..f656665 100644
--- a/kernel/include/ivy/sched.h
+++ b/kernel/include/ivy/sched.h
@@ -1,5 +1,6 @@
 #pragma once
 
+#include "ivy/status.h"
 #include <sys/queue.h>
 #include "ivy/dpc.h"
 #include "ivy/timer.h"
@@ -56,6 +57,9 @@ typedef struct thread {
 	WaitBlock *wait_block_table;
 	WaitBlock thread_wait_blocks[THREAD_WAIT_BLOCKS];
 
+	Timer timeout;
+	WaitBlock timeout_wait_block;
+
 	TAILQ_ENTRY(thread) entry;
 } Thread;
 
@@ -100,7 +104,9 @@ void sched_exit_self();
 
 Thread *sched_satisfy_object(ObjHeader *object, int boost, int all, int status);
 
-int sched_wait_multi(int waitmode, time_t timeout_ms, size_t objcount,
-		     ObjHeader **objtable, WaitBlock *wbtable);
+#define TIMEOUT_NONE 0
 
-int sched_wait(int waitmode, time_t timeout_ms, ObjHeader *obj);
+OsStatus sched_wait_multi(int waitmode, time_t timeout_ms, size_t objcount,
+			  ObjHeader **objtable, WaitBlock *wbtable);
+OsStatus sched_wait(int waitmode, time_t timeout_ms, ObjHeader *obj);
+OsStatus sleep(int waitmode, time_t ms);
diff --git a/kernel/include/ivy/status.h b/kernel/include/ivy/status.h
index ebf64a6..9dd9618 100644
--- a/kernel/include/ivy/status.h
+++ b/kernel/include/ivy/status.h
@@ -5,4 +5,7 @@ enum {
 	IVY_NOSUPPORT,
 	IVY_NOSPACE,
 	IVY_INUSE,
+	IVY_WAIT_TIMEOUT,
 };
+
+typedef int OsStatus;
diff --git a/kernel/include/ivy/timer.h b/kernel/include/ivy/timer.h
index 07b4982..d8828d1 100644
--- a/kernel/include/ivy/timer.h
+++ b/kernel/include/ivy/timer.h
@@ -41,3 +41,4 @@ void timer_init(Timer *timer, Dpc *dpc);
 void timer_reset(Timer *timer, Timespec deadline);
 void timer_reset_add(Timer *timer, time_t ms);
 void timer_install(Timer *timer, void *ctx);
+void timer_uninstall(Timer *timer);
diff --git a/kernel/src/init.c b/kernel/src/init.c
index a76625c..535b1c3 100644
--- a/kernel/src/init.c
+++ b/kernel/src/init.c
@@ -6,6 +6,7 @@
 #include "ivy/kmem.h"
 #include "ivy/log.h"
 #include "ivy/sched.h"
+#include "ivy/status.h"
 #include "ivy/timer.h"
 #include "ivy/vm.h"
 #include "ivy/percpu.h"
@@ -39,7 +40,7 @@ void print_loop(void *ctx)
 {
 	int cnt = 0;
 	for (;;) {
-		printk("%s", (const char *)ctx);
+		///printk("%s", (const char *)ctx);
 		if (++cnt == 5)
 			sched_exit_self();
 	}
@@ -62,10 +63,13 @@ void kmain_thread(void *)
 
 	Timer timer;
 	timer_init(&timer, NULL);
-	timer_reset_add(&timer, 500);
+	timer_reset_add(&timer, 2000);
 	timer_install(&timer, NULL);
 
-	sched_wait(0, 0, &timer.hdr);
+	for (;;) {
+		sleep(0, 500);
+	}
+	timer_uninstall(&timer);
 
 	printk(LOG_INFO "timer has fired, exit from wait\n");
 
diff --git a/kernel/src/irq/softint.c b/kernel/src/irq/softint.c
index 3f4cffd..607bd02 100644
--- a/kernel/src/irq/softint.c
+++ b/kernel/src/irq/softint.c
@@ -3,6 +3,7 @@
 #include "ivy/ipl.h"
 #include "ivy/softint.h"
 #include "ivy-internal/sched.h"
+#include "ivy/log.h"
 
 #define PENDING(irql) ((1 << ((irql) - 1)))
 
diff --git a/kernel/src/sched/sched.c b/kernel/src/sched/sched.c
index 12df681..7bd2166 100644
--- a/kernel/src/sched/sched.c
+++ b/kernel/src/sched/sched.c
@@ -1,3 +1,4 @@
+#include "ivy/log.h"
 #include <assert.h>
 #include <sys/queue.h>
 #include "ivy/dpc.h"
@@ -161,9 +162,10 @@ void sched_ready(Thread *thread)
 
 void sched_yield(Thread *current, CpuData *data)
 {
-	Ipl ipl = spinlock_acquire(&data->sched.rq_lock);
+	assert(spinlock_held(&current->lock));
+	spinlock_acquire_elevated(&data->sched.rq_lock);
 	Thread *next = next_thread(&data->sched, 0);
-	spinlock_release(&data->sched.rq_lock, ipl);
+	spinlock_release_elevated(&data->sched.rq_lock);
 
 	if (next) {
 		sched_switch(current, next);
diff --git a/kernel/src/sched/thread.c b/kernel/src/sched/thread.c
index 16e5526..d8c27ee 100644
--- a/kernel/src/sched/thread.c
+++ b/kernel/src/sched/thread.c
@@ -1,4 +1,6 @@
+#include "ivy/status.h"
 #include <assert.h>
+#include "ivy/timer.h"
 #include "ivy/sched.h"
 #include "ivy-internal/sched.h"
 #include "ivy/vm.h"
@@ -15,6 +17,12 @@ void thread_init(Thread *thread, ThreadEntryFn entry, int priority,
 	thread->timeslice_ms = 15;
 	SPINLOCK_INIT(&thread->lock);
 
+	timer_init(&thread->timeout, NULL);
+
+	thread->timeout_wait_block.object = &thread->timeout.hdr;
+	thread->timeout_wait_block.wake_status = IVY_WAIT_TIMEOUT;
+	thread->timeout_wait_block.thread = thread;
+
 	context_init(thread, 0, entry, context);
 }
 
diff --git a/kernel/src/sched/wait.c b/kernel/src/sched/wait.c
index c7ff542..577bcae 100644
--- a/kernel/src/sched/wait.c
+++ b/kernel/src/sched/wait.c
@@ -36,6 +36,9 @@ OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 SOFTWARE.
 */
 
+#include "ivy/log.h"
+#include "ivy/status.h"
+#include "ivy/timer.h"
 #include <assert.h>
 #include <stddef.h>
 #include "ivy/cpudata.h"
@@ -56,7 +59,7 @@ static void dequeue_waitblock(WaitBlock *waitblock)
 	spinlock_release_elevated(&object->obj_lock);
 }
 
-int sched_wait_thread(Thread *thread, int hastimeout)
+OsStatus sched_wait_thread(Thread *thread, int hastimeout)
 {
 	assert(spinlock_held(&thread->lock));
 	CpuData *data = curcpu();
@@ -75,7 +78,11 @@ int sched_wait_thread(Thread *thread, int hastimeout)
 		wb++;
 	}
 
-	assert(hastimeout == 0);
+	if (hastimeout) {
+		wb = &thread->timeout_wait_block;
+		dequeue_waitblock(wb);
+		timer_uninstall(&thread->timeout);
+	}
 
 	// thread lock dropped, still IPL@DISPATCH
 
@@ -104,9 +111,13 @@ void sched_unwait_thread(Thread *thread, int status, int boost)
 		wb++;
 	}
 
+	thread->timeout_wait_block.flags |= WB_UNWAITED;
+
 	// NOTE: could do quantum stuff
 
-	sched_internal_ready(thread);
+	if (thread->status == THREAD_WAITING) {
+		sched_internal_ready(thread);
+	}
 }
 
 Thread *sched_satisfy_object(ObjHeader *object, int boost, int all, int status)
@@ -141,8 +152,8 @@ Thread *sched_satisfy_object(ObjHeader *object, int boost, int all, int status)
 	return NULL;
 }
 
-int sched_wait_multi(int waitmode, time_t timeout_ms, size_t objcount,
-		     ObjHeader **objtable, WaitBlock *wbtable)
+OsStatus sched_wait_multi(int waitmode, time_t timeout_ms, size_t objcount,
+			  ObjHeader **objtable, WaitBlock *wbtable)
 {
 	assert(objcount > 0 && objcount < 255);
 	Thread *thread = curthread();
@@ -164,6 +175,9 @@ int sched_wait_multi(int waitmode, time_t timeout_ms, size_t objcount,
 
 	assert(curipl() < IPL_DISPATCH);
 	Ipl ipl = ripl(IPL_DISPATCH);
+
+	thread->timeout_wait_block.flags = 0;
+
 	thread->wait_mode = waitmode;
 	thread->wait_ipl = ipl;
 
@@ -178,6 +192,7 @@ int sched_wait_multi(int waitmode, time_t timeout_ms, size_t objcount,
 	size_t i;
 	int status;
 	ObjHeader *obj;
+	Timer *timer;
 
 	for (i = 0; i < objcount; i++) {
 		obj = objtable[i];
@@ -209,13 +224,26 @@ int sched_wait_multi(int waitmode, time_t timeout_ms, size_t objcount,
 		spinlock_release_elevated(&obj->obj_lock);
 	}
 
-	assert(!timeout_ms);
+	if (timeout_ms) {
+		WaitBlock *wb = &thread->timeout_wait_block;
+		timer = &thread->timeout;
+
+		TAILQ_INSERT_TAIL(&timer->hdr.waiter_list, wb, entry);
+		timer->hdr.waiter_count = 1;
+
+		timer_reset_add(timer, timeout_ms);
+		timer_install(timer, NULL);
+	}
 
 	spinlock_acquire_elevated(&thread->lock);
 
 	if (thread->wait_attempt == THREAD_WAIT_ABORTED) {
 		spinlock_release_elevated(&thread->lock);
 		if (timeout_ms) {
+			WaitBlock *wb = &thread->timeout_wait_block;
+			timer = &thread->timeout;
+			timer_uninstall(timer);
+			TAILQ_REMOVE(&timer->hdr.waiter_list, wb, entry);
 		}
 
 		status = thread->wait_status;
@@ -231,7 +259,7 @@ int sched_wait_multi(int waitmode, time_t timeout_ms, size_t objcount,
 	return status;
 }
 
-int sched_wait(int waitmode, time_t timeout_ms, ObjHeader *obj)
+OsStatus sched_wait(int waitmode, time_t timeout_ms, ObjHeader *obj)
 {
 	Thread *thread = curthread();
 	WaitBlock singlewaitblock;
@@ -245,6 +273,7 @@ int sched_wait(int waitmode, time_t timeout_ms, ObjHeader *obj)
 
 	assert(curipl() < IPL_DISPATCH);
 	Ipl ipl = ripl(IPL_DISPATCH);
+	thread->timeout_wait_block.flags = 0;
 	thread->wait_mode = waitmode;
 	thread->wait_ipl = ipl;
 	thread->wait_block_table = NULL;
@@ -272,11 +301,28 @@ int sched_wait(int waitmode, time_t timeout_ms, ObjHeader *obj)
 	obj->waiter_count += 1;
 	spinlock_release_elevated(&obj->obj_lock);
 
+	if (timeout_ms) {
+		WaitBlock *wb = &thread->timeout_wait_block;
+		Timer *timer = &thread->timeout;
+		TAILQ_INSERT_TAIL(&timer->hdr.waiter_list, wb, entry);
+		timer->hdr.waiter_count = 1;
+
+		timer_reset_add(timer, timeout_ms);
+		timer_install(timer, NULL);
+	}
+
 	spinlock_acquire_elevated(&thread->lock);
 
 	if (thread->wait_attempt == THREAD_WAIT_ABORTED) {
 		spinlock_release_elevated(&thread->lock);
 
+		if (timeout_ms) {
+			WaitBlock *wb = &thread->timeout_wait_block;
+			Timer *timer = &thread->timeout;
+			timer_uninstall(timer);
+			TAILQ_REMOVE(&timer->hdr.waiter_list, wb, entry);
+		}
+
 		status = thread->wait_status;
 		dequeue_waitblock(&singlewaitblock);
 		thread->wait_attempt = THREAD_WAIT_NONE;
@@ -294,3 +340,54 @@ int sched_wait(int waitmode, time_t timeout_ms, ObjHeader *obj)
 
 	return status;
 }
+
+OsStatus sleep(int waitmode, time_t ms)
+{
+	Thread *thread = curthread();
+
+retry:
+
+	assert(curipl() < IPL_DISPATCH);
+	Ipl ipl = ripl(IPL_DISPATCH);
+	thread->timeout_wait_block.flags = 0;
+	thread->wait_mode = waitmode;
+	thread->wait_ipl = ipl;
+	thread->wait_block_table = NULL;
+	thread->wait_count = 0;
+	spinlock_acquire_elevated(&thread->lock);
+	// NOTE: check for all kinds of stuff here
+	thread->wait_attempt = THREAD_WAIT_TRY;
+	spinlock_release_elevated(&thread->lock);
+
+	OsStatus status = 0;
+
+	WaitBlock *wb = &thread->timeout_wait_block;
+	Timer *timer = &thread->timeout;
+	TAILQ_INSERT_TAIL(&timer->hdr.waiter_list, wb, entry);
+	timer->hdr.waiter_count = 1;
+	timer_reset_add(timer, ms);
+	timer_install(timer, NULL);
+
+	spinlock_acquire_elevated(&thread->lock);
+
+	if (thread->wait_attempt == THREAD_WAIT_ABORTED) {
+		spinlock_release_elevated(&thread->lock);
+
+		timer_uninstall(timer);
+		TAILQ_REMOVE(&timer->hdr.waiter_list, wb, entry);
+
+		status = thread->wait_status;
+		thread->wait_attempt = THREAD_WAIT_NONE;
+
+		xipl(ipl);
+		return status;
+	}
+
+	thread->wait_attempt = THREAD_WAIT_COMMITTED;
+
+	status = sched_wait_thread(thread, 1);
+
+	xipl(ipl);
+
+	return status;
+}
diff --git a/kernel/src/time/timer.c b/kernel/src/time/timer.c
index 2dbacf1..f6aa657 100644
--- a/kernel/src/time/timer.c
+++ b/kernel/src/time/timer.c
@@ -2,14 +2,13 @@
 #include "ivy/cpudata.h"
 #include "ivy/dpc.h"
 #include "ivy/heap.h"
-#include "ivy/log.h"
 #include "ivy/object.h"
 #include "ivy/time.h"
 #include "ivy/timespec.h"
 
 static int timer_cmp(Timer *a, Timer *b)
 {
-	return timespec_cmp(a->deadline, b->deadline) == 1;
+	return timespec_cmp(a->deadline, b->deadline) < 0;
 }
 
 HEAP_IMPL(timerlist, timer, entry, timer_cmp);
@@ -36,7 +35,7 @@ void timer_init(Timer *timer, Dpc *dpc)
 	HEAP_ENTRY_INIT(timer, entry);
 }
 
-void timer_uninstall(Timer *timer, int flags)
+void timer_uninstall(Timer *timer)
 {
 	TimerEngine *engine = timer->engine;
 	if (engine) {
@@ -60,7 +59,7 @@ void timer_reset(Timer *timer, Timespec deadline)
 	Ipl ipl = spinlock_acquire(&timer->hdr.obj_lock);
 	if (timer->state == TIMER_QUEUED) {
 		spinlock_release(&timer->hdr.obj_lock, ipl);
-		timer_uninstall(timer, 0);
+		timer_uninstall(timer);
 		ipl = spinlock_acquire(&timer->hdr.obj_lock);
 	}
 	timer->deadline = deadline;