diff --git a/trunk/bootrom/build/libraries/init/ARM11/crt0_scat.c b/trunk/bootrom/build/libraries/init/ARM11/crt0_scat.c
index 4715430..3fbd566 100644
--- a/trunk/bootrom/build/libraries/init/ARM11/crt0_scat.c
+++ b/trunk/bootrom/build/libraries/init/ARM11/crt0_scat.c
@@ -45,6 +45,9 @@ ASM void $Sub$$stupInitSections(void)
 int main( void )
 {
     BromMain();
-    return 0;
+    while (1)
+    {
+    }
+    // never return
 }
 
diff --git a/trunk/bootrom/build/libraries/init/ARM9/crt0_scat.c b/trunk/bootrom/build/libraries/init/ARM9/crt0_scat.c
index 601c1ba..fac0db9 100644
--- a/trunk/bootrom/build/libraries/init/ARM9/crt0_scat.c
+++ b/trunk/bootrom/build/libraries/init/ARM9/crt0_scat.c
@@ -45,6 +45,9 @@ ASM void $Sub$$stupInitSections(void)
 int main( void )
 {
     BromSpMain();
-    return 0;
+    while (1)
+    {
+    }
+    // never return
 }
 
diff --git a/trunk/bootrom/build/libraries/os/ARM11/os_timer.c b/trunk/bootrom/build/libraries/os/ARM11/os_timer.c
index 51f8b7f..13882b3 100644
--- a/trunk/bootrom/build/libraries/os/ARM11/os_timer.c
+++ b/trunk/bootrom/build/libraries/os/ARM11/os_timer.c
@@ -16,12 +16,7 @@
  *---------------------------------------------------------------------------*/
 #include <brom/os.h>
 
-void timer_handler(void);
 
-#if 0 // miya
-static void i_osTimerInterruptHandler(void);
-static void i_osWatchdogInterruptHandler( void );
-#endif
 static void i_osStartTimer( u32 count, u8 preScale, OSTimerRepeat repeat, OSTimerIntrReq ireq );
 static void i_osStartWatchdog( u32 count, u8 preScale, OSTimerRepeat repeat, OSTimerIntrReq ireq, 
                                OSWatchdogMode watchdogMode );
@@ -45,49 +40,22 @@ void osInitTimer( void )
 
     if ( isInit == FALSE )
     {
+        OSIntrMode intr = osDisableInterrupts();
+
         isInit = TRUE;
 
         osTimerClock = OS_TIMER_CLOCK_DEFAULT;
 
         osStopTimer();
         osStopWatchdog();
+        osResetWatchdog();
+        osDisableWatchdog();
+
+        osRestoreInterrupts( intr );
     }
 }
 
 
-/*---------------------------------------------------------------------------*
-  Name:         i_osTimerInterruptHandler
-
-  Description:  Timer interrupt handler
-
-  Arguments:    None.
-
-  Returns:      None.
- *---------------------------------------------------------------------------*/
-#if 0 // miya
-static void i_osTimerInterruptHandler( void )
-{
-    reg_OS_CPUTM_EVT = HW_CPUTM_EVT_FLAG;
-}
-
-/*---------------------------------------------------------------------------*
-  Name:         i_osWatchdogInterruptHandler
-
-  Description:  Watchdog interrupt handler
-
-  Arguments:    None.
-
-  Returns:      None.
- *---------------------------------------------------------------------------*/
-
-
-static void i_osWatchdogInterruptHandler( void )
-{
-    reg_OS_CPUWD_EVT = HW_CPUWD_EVT_FLAG;
-}
-#endif
-
-
 /*---------------------------------------------------------------------------*
   Name:         osStartTimerWithUSec
 
@@ -292,7 +260,12 @@ void osResetWatchdog( void )
 
 void osDisableWatchdog( void )
 {
-    reg_OS_WD_DIS = TRUE;
+    OSIntrMode intr = osDisableInterrupts();
+
+    reg_OS_WD_DIS = OSi_WATCHDOG_DISABLE_CODE_0;
+    reg_OS_WD_DIS = OSi_WATCHDOG_DISABLE_CODE_1;
+
+    osRestoreInterrupts( intr );
 }
 
 #include <brom/code32.h>
diff --git a/trunk/bootrom/build/libraries/os/common/os_init.c b/trunk/bootrom/build/libraries/os/common/os_init.c
index db61d86..9934bd0 100644
--- a/trunk/bootrom/build/libraries/os/common/os_init.c
+++ b/trunk/bootrom/build/libraries/os/common/os_init.c
@@ -20,6 +20,10 @@
 //#define FIRM_ENABLE_JTAG_AT_INIT
 
 
+static void handler(void)
+{
+}
+
 /*---------------------------------------------------------------------------*
   Name:         osInitBROM
 
@@ -51,8 +55,14 @@ void osInitBROM(void)
         //---- Init Tick
         osInitTick();
 
+#if 1
         //---- Init Alarm
-//        osInitAlarm();
+        osInitAlarm();
+        {
+            static OSAlarm alarm;
+            osSetPeriodicAlarm(&alarm, 0x1000, 0x1000, (OSAlarmHandler)handler, NULL);
+        }
+#endif
     }
 }
 
diff --git a/trunk/bootrom/include/brom/os/ARM11/timer.h b/trunk/bootrom/include/brom/os/ARM11/timer.h
index c02ac7a..056feb7 100644
--- a/trunk/bootrom/include/brom/os/ARM11/timer.h
+++ b/trunk/bootrom/include/brom/os/ARM11/timer.h
@@ -24,7 +24,10 @@
 extern "C" {
 #endif
 
-#define OS_TIMER_CLOCK_DEFAULT  HW_CPU_CLOCK
+#define OS_TIMER_CLOCK_DEFAULT          HW_CPU_CLOCK
+
+#define OSi_WATCHDOG_DISABLE_CODE_0     0x12345678
+#define OSi_WATCHDOG_DISABLE_CODE_1     0x87654321
 
 
 //----------------------------------------------------------------------