diff --git a/PcAtChipsetPkg/PcatRealTimeClockRuntimeDxe/PcRtc.c b/PcAtChipsetPkg/PcatRealTimeClockRuntimeDxe/PcRtc.c
index a77009a217..eb1a6567ee 100644
--- a/PcAtChipsetPkg/PcatRealTimeClockRuntimeDxe/PcRtc.c
+++ b/PcAtChipsetPkg/PcatRealTimeClockRuntimeDxe/PcRtc.c
@@ -104,6 +104,8 @@ PcRtcInit (
   EFI_TIME        Time;
   UINTN           DataSize;
   UINT32          TimerVar;
+  BOOLEAN         Enabled;
+  BOOLEAN         Pending;
 
   //
   // Acquire RTC Lock to make access to RTC atomic
@@ -226,11 +228,96 @@ PcRtcInit (
   // Reset time value according to new RTC configuration
   //
   Status = PcRtcSetTime (&Time, Global);
-  if(!EFI_ERROR (Status)) {
-    return EFI_SUCCESS;
-  } else {
+  if (EFI_ERROR (Status)) {
     return EFI_DEVICE_ERROR;
   }
+  
+  //
+  // Reset wakeup time value to valid state when wakeup alarm is disabled and wakeup time is invalid.
+  // Global variable has already had valid SavedTimeZone and Daylight,
+  // so we can use them to get and set wakeup time.
+  //
+  Status = PcRtcGetWakeupTime (&Enabled, &Pending, &Time, Global);
+  if ((Enabled) || (!EFI_ERROR (Status))) {
+    return EFI_SUCCESS;
+  }
+  
+  //
+  // When wakeup time is disabled and invalid, reset wakeup time register to valid state 
+  // but keep wakeup alarm disabled.
+  //
+  Time.Second = RTC_INIT_SECOND;
+  Time.Minute = RTC_INIT_MINUTE;
+  Time.Hour   = RTC_INIT_HOUR;
+  Time.Day    = RTC_INIT_DAY;
+  Time.Month  = RTC_INIT_MONTH;
+  Time.Year   = RTC_INIT_YEAR;
+  Time.Nanosecond  = 0;
+  Time.TimeZone = Global->SavedTimeZone;
+  Time.Daylight = Global->Daylight;;
+
+  //
+  // Acquire RTC Lock to make access to RTC atomic
+  //
+  if (!EfiAtRuntime ()) {
+    EfiAcquireLock (&Global->RtcLock);
+  }
+  //
+  // Wait for up to 0.1 seconds for the RTC to be updated
+  //
+  Status = RtcWaitToUpdate (PcdGet32 (PcdRealTimeClockUpdateTimeout));
+  if (EFI_ERROR (Status)) {
+    if (!EfiAtRuntime ()) {
+    EfiReleaseLock (&Global->RtcLock);
+    }
+    return EFI_DEVICE_ERROR;
+  }
+  
+  ConvertEfiTimeToRtcTime (&Time, RegisterB, &Century);
+
+  //
+  // Set the Y/M/D info to variable as it has no corresponding hw registers.
+  //
+  Status =  EfiSetVariable (
+              L"RTCALARM",
+              &gEfiCallerIdGuid,
+              EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS | EFI_VARIABLE_NON_VOLATILE,
+              sizeof (Time),
+              &Time
+              );
+  if (EFI_ERROR (Status)) {
+    if (!EfiAtRuntime ()) {
+      EfiReleaseLock (&Global->RtcLock);
+    }
+    return EFI_DEVICE_ERROR;
+  }
+  
+  //
+  // Inhibit updates of the RTC
+  //
+  RegisterB.Bits.Set  = 1;
+  RtcWrite (RTC_ADDRESS_REGISTER_B, RegisterB.Data);
+ 
+  //
+  // Set RTC alarm time registers
+  //
+  RtcWrite (RTC_ADDRESS_SECONDS_ALARM, Time.Second);
+  RtcWrite (RTC_ADDRESS_MINUTES_ALARM, Time.Minute);
+  RtcWrite (RTC_ADDRESS_HOURS_ALARM, Time.Hour);
+
+  //
+  // Allow updates of the RTC registers
+  //
+  RegisterB.Bits.Set = 0;
+  RtcWrite (RTC_ADDRESS_REGISTER_B, RegisterB.Data);
+ 
+  //
+  // Release RTC Lock.
+  //
+  if (!EfiAtRuntime ()) {
+    EfiReleaseLock (&Global->RtcLock);
+  }
+  return EFI_SUCCESS;
 }
 
 /**