Index: kernel/arch/mips32/include/arch/drivers/msim.h
===================================================================
--- kernel/arch/mips32/include/arch/drivers/msim.h	(revision 903b54557c34b5d1fc13e929901511b8b04a676e)
+++ kernel/arch/mips32/include/arch/drivers/msim.h	(revision 749fe15b74e83e98f982655fff497a808f7675f4)
@@ -39,5 +39,7 @@
 #define MSIM_VIDEORAM     0x90000000
 #define MSIM_KBD_ADDRESS  0x90000000
+
 #define MSIM_KBD_IRQ      2
+#define MSIM_DDISK_IRQ    6
 
 #endif
Index: kernel/arch/mips32/src/mach/msim/msim.c
===================================================================
--- kernel/arch/mips32/src/mach/msim/msim.c	(revision 903b54557c34b5d1fc13e929901511b8b04a676e)
+++ kernel/arch/mips32/src/mach/msim/msim.c	(revision 749fe15b74e83e98f982655fff497a808f7675f4)
@@ -62,4 +62,5 @@
 void msim_init(void)
 {
+	cp0_unmask_int(MSIM_DDISK_IRQ);
 }