diff --git a/src/lib/ultra/os/timerintr.c b/src/lib/ultra/os/timerintr.c
index 692fd06d3..977818eb2 100644
--- a/src/lib/ultra/os/timerintr.c
+++ b/src/lib/ultra/os/timerintr.c
@@ -41,110 +41,50 @@ glabel __osTimerServicesInit
 /*    49238:	af00001c */ 	sw	$zero,0x1c($t8)
 );
 
-GLOBAL_ASM(
-glabel __osTimerInterrupt
-/*    4923c:	3c0e8006 */ 	lui	$t6,%hi(__osTimerList)
-/*    49240:	8dce08a0 */ 	lw	$t6,%lo(__osTimerList)($t6)
-/*    49244:	27bdffd8 */ 	addiu	$sp,$sp,-40
-/*    49248:	afbf0014 */ 	sw	$ra,0x14($sp)
-/*    4924c:	8dcf0000 */ 	lw	$t7,0x0($t6)
-/*    49250:	11ee0054 */ 	beq	$t7,$t6,.L000493a4
-/*    49254:	00000000 */ 	nop
-.L00049258:
-/*    49258:	3c188006 */ 	lui	$t8,%hi(__osTimerList)
-/*    4925c:	8f1808a0 */ 	lw	$t8,%lo(__osTimerList)($t8)
-/*    49260:	8f190000 */ 	lw	$t9,0x0($t8)
-/*    49264:	17380006 */ 	bne	$t9,$t8,.L00049280
-/*    49268:	afb90024 */ 	sw	$t9,0x24($sp)
-/*    4926c:	0c014620 */ 	jal	__osSetCompare
-/*    49270:	00002025 */ 	or	$a0,$zero,$zero
-/*    49274:	3c01800a */ 	lui	$at,%hi(__osTimerCounter)
-/*    49278:	1000004a */ 	b	.L000493a4
-/*    4927c:	ac20c790 */ 	sw	$zero,%lo(__osTimerCounter)($at)
-.L00049280:
-/*    49280:	0c012144 */ 	jal	osGetCount
-/*    49284:	00000000 */ 	nop
-/*    49288:	afa20020 */ 	sw	$v0,0x20($sp)
-/*    4928c:	3c09800a */ 	lui	$t1,%hi(__osTimerCounter)
-/*    49290:	8d29c790 */ 	lw	$t1,%lo(__osTimerCounter)($t1)
-/*    49294:	8fa80020 */ 	lw	$t0,0x20($sp)
-/*    49298:	8faf0024 */ 	lw	$t7,0x24($sp)
-/*    4929c:	3c01800a */ 	lui	$at,%hi(__osTimerCounter)
-/*    492a0:	01095023 */ 	subu	$t2,$t0,$t1
-/*    492a4:	afaa001c */ 	sw	$t2,0x1c($sp)
-/*    492a8:	ac28c790 */ 	sw	$t0,%lo(__osTimerCounter)($at)
-/*    492ac:	8dee0010 */ 	lw	$t6,0x10($t7)
-/*    492b0:	8fab001c */ 	lw	$t3,0x1c($sp)
-/*    492b4:	240c0000 */ 	addiu	$t4,$zero,0x0
-/*    492b8:	01e0c825 */ 	or	$t9,$t7,$zero
-/*    492bc:	01cc082b */ 	sltu	$at,$t6,$t4
-/*    492c0:	8def0014 */ 	lw	$t7,0x14($t7)
-/*    492c4:	14200016 */ 	bnez	$at,.L00049320
-/*    492c8:	01606825 */ 	or	$t5,$t3,$zero
-/*    492cc:	018e082b */ 	sltu	$at,$t4,$t6
-/*    492d0:	14200003 */ 	bnez	$at,.L000492e0
-/*    492d4:	01af082b */ 	sltu	$at,$t5,$t7
-/*    492d8:	10200011 */ 	beqz	$at,.L00049320
-/*    492dc:	00000000 */ 	nop
-.L000492e0:
-/*    492e0:	27380010 */ 	addiu	$t8,$t9,0x10
-/*    492e4:	afb80018 */ 	sw	$t8,0x18($sp)
-/*    492e8:	8f2b0014 */ 	lw	$t3,0x14($t9)
-/*    492ec:	8f2a0010 */ 	lw	$t2,0x10($t9)
-/*    492f0:	016d082b */ 	sltu	$at,$t3,$t5
-/*    492f4:	014c4023 */ 	subu	$t0,$t2,$t4
-/*    492f8:	01014023 */ 	subu	$t0,$t0,$at
-/*    492fc:	016d4823 */ 	subu	$t1,$t3,$t5
-/*    49300:	af290014 */ 	sw	$t1,0x14($t9)
-/*    49304:	af280010 */ 	sw	$t0,0x10($t9)
-/*    49308:	8fae0024 */ 	lw	$t6,0x24($sp)
-/*    4930c:	8dc40010 */ 	lw	$a0,0x10($t6)
-/*    49310:	0c0124ed */ 	jal	__osSetTimerIntr
-/*    49314:	8dc50014 */ 	lw	$a1,0x14($t6)
-/*    49318:	10000022 */ 	b	.L000493a4
-/*    4931c:	00000000 */ 	nop
-.L00049320:
-/*    49320:	8faf0024 */ 	lw	$t7,0x24($sp)
-/*    49324:	8df80000 */ 	lw	$t8,0x0($t7)
-/*    49328:	8dea0004 */ 	lw	$t2,0x4($t7)
-/*    4932c:	ad580000 */ 	sw	$t8,0x0($t2)
-/*    49330:	8fab0024 */ 	lw	$t3,0x24($sp)
-/*    49334:	8d6c0004 */ 	lw	$t4,0x4($t3)
-/*    49338:	8d6d0000 */ 	lw	$t5,0x0($t3)
-/*    4933c:	adac0004 */ 	sw	$t4,0x4($t5)
-/*    49340:	8fa80024 */ 	lw	$t0,0x24($sp)
-/*    49344:	ad000000 */ 	sw	$zero,0x0($t0)
-/*    49348:	8fa90024 */ 	lw	$t1,0x24($sp)
-/*    4934c:	ad200004 */ 	sw	$zero,0x4($t1)
-/*    49350:	8fb90024 */ 	lw	$t9,0x24($sp)
-/*    49354:	8f2e0018 */ 	lw	$t6,0x18($t9)
-/*    49358:	11c00005 */ 	beqz	$t6,.L00049370
-/*    4935c:	00000000 */ 	nop
-/*    49360:	01c02025 */ 	or	$a0,$t6,$zero
-/*    49364:	8f25001c */ 	lw	$a1,0x1c($t9)
-/*    49368:	0c012238 */ 	jal	osSendMesg
-/*    4936c:	00003025 */ 	or	$a2,$zero,$zero
-.L00049370:
-/*    49370:	8faf0024 */ 	lw	$t7,0x24($sp)
-/*    49374:	8df80008 */ 	lw	$t8,0x8($t7)
-/*    49378:	8df9000c */ 	lw	$t9,0xc($t7)
-/*    4937c:	17000003 */ 	bnez	$t8,.L0004938c
-/*    49380:	00000000 */ 	nop
-/*    49384:	1320ffb4 */ 	beqz	$t9,.L00049258
-/*    49388:	00000000 */ 	nop
-.L0004938c:
-/*    4938c:	adf80010 */ 	sw	$t8,0x10($t7)
-/*    49390:	adf90014 */ 	sw	$t9,0x14($t7)
-/*    49394:	0c01250a */ 	jal	__osInsertTimer
-/*    49398:	8fa40024 */ 	lw	$a0,0x24($sp)
-/*    4939c:	1000ffae */ 	b	.L00049258
-/*    493a0:	00000000 */ 	nop
-.L000493a4:
-/*    493a4:	8fbf0014 */ 	lw	$ra,0x14($sp)
-/*    493a8:	27bd0028 */ 	addiu	$sp,$sp,0x28
-/*    493ac:	03e00008 */ 	jr	$ra
-/*    493b0:	00000000 */ 	nop
-);
+void __osTimerInterrupt(void)
+{
+	OSTimer *t;
+	u32 count;
+	u32 elapsed_cycles;
+
+	if (__osTimerList->next == __osTimerList) {
+		return;
+	}
+
+	while (1) {
+		t = __osTimerList->next;
+
+		if (t == __osTimerList) {
+			__osSetCompare(0);
+			__osTimerCounter = 0;
+			break;
+		}
+
+		count = osGetCount();
+		elapsed_cycles = count - __osTimerCounter;
+		__osTimerCounter = count;
+
+		if (elapsed_cycles < t->remaining) {
+			t->remaining -= elapsed_cycles;
+			__osSetTimerIntr(t->remaining);
+			return;
+		} else {
+			t->prev->next = t->next;
+			t->next->prev = t->prev;
+			t->next = NULL;
+			t->prev = NULL;
+
+			if (t->mq != NULL) {
+				osSendMesg(t->mq, t->msg, OS_MESG_NOBLOCK);
+			}
+
+			if (t->interval != 0) {
+				t->remaining = t->interval;
+				__osInsertTimer(t);
+			}
+		}
+	}
+}
 
 void __osSetTimerIntr(OSTime tim)
 {