diff --git a/src/lib/ultra/os/invalicache.s b/src/lib/ultra/os/invalicache.s
new file mode 100644
index 000000000..a99d40138
--- /dev/null
+++ b/src/lib/ultra/os/invalicache.s
@@ -0,0 +1,40 @@
+#include "macros.inc"
+.set noat
+.set noreorder
+
+.section .text
+
+glabel osInvalICache
+	blez  $a1, .L00048198
+ 	nop
+	addiu $t3, $zero, 0x4000
+	sltu  $at, $a1, $t3
+	beqz  $at, .L000481a0
+ 	nop
+	move  $t0, $a0
+	addu  $t1, $a0, $a1
+	sltu  $at, $t0, $t1
+	beqz  $at, .L00048198
+ 	nop
+	andi  $t2, $t0, 0x1f
+	addiu $t1, $t1, -32
+	subu  $t0, $t0, $t2
+.L00048188:
+	cache 0x10, 0x0($t0)
+	sltu  $at, $t0, $t1
+	bnez  $at, .L00048188
+	addiu $t0, $t0, 0x20
+.L00048198:
+	jr    $ra
+ 	nop
+.L000481a0:
+	lui   $t0, 0x8000
+	addu  $t1, $t0, $t3
+	addiu $t1, $t1, -32
+.L000481ac:
+	cache 0x0, 0x0($t0)
+	sltu  $at, $t0, $t1
+	bnez  $at, .L000481ac
+	addiu $t0, $t0, 0x20
+	jr    $ra
+ 	nop