text: /** @file
    Routines implements SIMPLE_TEXT_IN protocol's interfaces based on 8042 interfaces
    provided by Ps2KbdCtrller.c.
  
  Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR>
  This program and the accompanying materials
  are licensed and made available under the terms and conditions of the BSD License
  which accompanies this distribution.  The full text of the license may be found at
  http://opensource.org/licenses/bsd-license.php
  
  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  
  **/
  
  
  #include "Ps2Keyboard.h"
  
  /**
    Check whether the EFI key buffer is empty.
  
    @param Queue     Pointer to instance of EFI_KEY_QUEUE.
  
    @retval TRUE    The EFI key buffer is empty.
    @retval FALSE   The EFI key buffer isn't empty.
  **/
  BOOLEAN
  IsEfikeyBufEmpty (
    IN  EFI_KEY_QUEUE         *Queue
    )
  {
    return (BOOLEAN) (Queue->Head == Queue->Tail);
  }
  
  /**
    Read & remove one key data from the EFI key buffer.
  
    @param Queue     Pointer to instance of EFI_KEY_QUEUE.
    @param KeyData   Receive the key data.
  
    @retval EFI_SUCCESS   The key data is popped successfully.
    @retval EFI_NOT_READY There is no key data available.
  **/
  EFI_STATUS
  PopEfikeyBufHead (
    IN  EFI_KEY_QUEUE         *Queue,
    OUT EFI_KEY_DATA          *KeyData OPTIONAL
    )
  {
    if (IsEfikeyBufEmpty (Queue)) {
      return EFI_NOT_READY;
    }
    //
    // Retrieve and remove the values
    //
    if (KeyData != NULL) {
      CopyMem(KeyData, &Queue->Buffer[Queue->Head], sizeof (EFI_KEY_DATA));
    }
    Queue->Head = (Queue->Head + 1) % KEYBOARD_EFI_KEY_MAX_COUNT;
    return EFI_SUCCESS;
  }
  
  /**
    Push one key data to the EFI key buffer.
  
    @param Queue     Pointer to instance of EFI_KEY_QUEUE.
    @param KeyData   The key data to push.
  **/
  VOID
  PushEfikeyBufTail (
    IN  EFI_KEY_QUEUE         *Queue,
    IN  EFI_KEY_DATA          *KeyData
    )
  {
    if ((Queue->Tail + 1) % KEYBOARD_EFI_KEY_MAX_COUNT == Queue->Head) {
      //
      // If Queue is full, pop the one from head.
      //
      PopEfikeyBufHead (Queue, NULL);
    }
    CopyMem(&Queue->Buffer[Queue->Tail], KeyData, sizeof (EFI_KEY_DATA));
    Queue->Tail = (Queue->Tail + 1) % KEYBOARD_EFI_KEY_MAX_COUNT;
  }
  
  /**
    Judge whether is a registed key
  
    @param RegsiteredData       A pointer to a buffer that is filled in with the keystroke
                                state data for the key that was registered.
    @param InputData            A pointer to a buffer that is filled in with the keystroke
                                state data for the key that was pressed.
  
    @retval TRUE                Key be pressed matches a registered key.
    @retval FLASE               Match failed.
  
  **/
  BOOLEAN
  IsKeyRegistered (
    IN EFI_KEY_DATA  *RegsiteredData,
    IN EFI_KEY_DATA  *InputData
    )
  
  {
    ASSERT (RegsiteredData != NULL && InputData != NULL);
  
    if ((RegsiteredData->Key.ScanCode    != InputData->Key.ScanCode) ||
        (RegsiteredData->Key.UnicodeChar != InputData->Key.UnicodeChar)) {
      return FALSE;
    }
  
    //
    // Assume KeyShiftState/KeyToggleState = 0 in Registered key data means these state could be ignored.
    //
    if (RegsiteredData->KeyState.KeyShiftState != 0 &&
        RegsiteredData->KeyState.KeyShiftState != InputData->KeyState.KeyShiftState) {
      return FALSE;
    }
    if (RegsiteredData->KeyState.KeyToggleState != 0 &&
        RegsiteredData->KeyState.KeyToggleState != InputData->KeyState.KeyToggleState) {
      return FALSE;
    }
  
    return TRUE;
  
  }
  
  /**
      Reads the next keystroke from the input device. The WaitForKey Event can
      be used to test for existance of a keystroke via WaitForEvent () call.
  
      @param ConsoleInDev          Ps2 Keyboard private structure
      @param KeyData               A pointer to a buffer that is filled in with the keystroke
                                   state data for the key that was pressed.
  
  
      @retval EFI_SUCCESS             The keystroke information was returned.
      @retval EFI_NOT_READY           There was no keystroke data availiable.
      @retval EFI_DEVICE_ERROR        The keystroke information was not returned due to
                                      hardware errors.
      @retval EFI_INVALID_PARAMETER   KeyData is NULL.
  
  **/
  EFI_STATUS
  KeyboardReadKeyStrokeWorker (
    IN  KEYBOARD_CONSOLE_IN_DEV           *ConsoleInDev,
    OUT EFI_KEY_DATA                      *KeyData
    )
  
  {
    EFI_STATUS                            Status;
    EFI_TPL                               OldTpl;
  
    if (KeyData == NULL) {
      return EFI_INVALID_PARAMETER;
    }
  
    //
    // Enter critical section
    //
    OldTpl = gBS->RaiseTPL (TPL_NOTIFY);
  
    KeyboardTimerHandler (NULL, ConsoleInDev);
  
    if (ConsoleInDev->KeyboardErr) {
      Status = EFI_DEVICE_ERROR;
    } else {
      Status = PopEfikeyBufHead (&ConsoleInDev->EfiKeyQueue, KeyData);
      if (Status == EFI_NOT_READY) {
        ZeroMem (&KeyData->Key, sizeof (KeyData->Key));
        InitializeKeyState (ConsoleInDev, &KeyData->KeyState);
      }
    }
  
    gBS->RestoreTPL (OldTpl);
    return Status;
  }
  
  /**
    Perform 8042 controller and keyboard initialization which implement SIMPLE_TEXT_IN.Reset()
  
    @param This                 Pointer to instance of EFI_SIMPLE_TEXT_INPUT_PROTOCOL
    @param ExtendedVerification Indicate that the driver may perform a more
                                exhaustive verification operation of the device during
                                reset, now this par is ignored in this driver
  
  **/
  EFI_STATUS
  EFIAPI
  KeyboardEfiReset (
    IN  EFI_SIMPLE_TEXT_INPUT_PROTOCOL  *This,
    IN  BOOLEAN                         ExtendedVerification
    )
  {
    EFI_STATUS              Status;
    KEYBOARD_CONSOLE_IN_DEV *ConsoleIn;
    EFI_TPL                 OldTpl;
  
    ConsoleIn = KEYBOARD_CONSOLE_IN_DEV_FROM_THIS (This);
    if (ConsoleIn->KeyboardErr) {
      return EFI_DEVICE_ERROR;
    }
  
    REPORT_STATUS_CODE_WITH_DEVICE_PATH (
      EFI_PROGRESS_CODE,
      EFI_PERIPHERAL_KEYBOARD | EFI_P_PC_RESET,
      ConsoleIn->DevicePath
      );
  
    //
    // Enter critical section
    //
    OldTpl = gBS->RaiseTPL (TPL_NOTIFY);
  
    //
    // Call InitKeyboard to initialize the keyboard
    //
    Status = InitKeyboard (ConsoleIn, ExtendedVerification);
    if (EFI_ERROR(Status)) {
      //
      // Leave critical section and return
      //
      gBS->RestoreTPL (OldTpl);
      return EFI_DEVICE_ERROR;
    }
  
    //
    // Leave critical section and return
    //
    gBS->RestoreTPL (OldTpl);
  
    //
    // Report the status If a stuck key was detected
    //
    if (KeyReadStatusRegister (ConsoleIn) & 0x01) {
      REPORT_STATUS_CODE_WITH_DEVICE_PATH (
        EFI_ERROR_CODE | EFI_ERROR_MINOR,
        EFI_PERIPHERAL_KEYBOARD | EFI_P_KEYBOARD_EC_STUCK_KEY,
        ConsoleIn->DevicePath
        );
    }
    //
    // Report the status If keyboard is locked
    //
    if ((KeyReadStatusRegister (ConsoleIn) & 0x10) == 0) {
      REPORT_STATUS_CODE_WITH_DEVICE_PATH (
        EFI_ERROR_CODE | EFI_ERROR_MINOR,
        EFI_PERIPHERAL_KEYBOARD | EFI_P_KEYBOARD_EC_LOCKED,
        ConsoleIn->DevicePath
        );
    }
  
    return EFI_SUCCESS;
  }
  
  /**
    Retrieve key values for driver user which implement SIMPLE_TEXT_IN.ReadKeyStroke().
  
    @param This    Pointer to instance of EFI_SIMPLE_TEXT_INPUT_PROTOCOL
    @param Key     The output buffer for key value
  
    @retval EFI_SUCCESS success to read key stroke
  **/
  EFI_STATUS
  EFIAPI
  KeyboardReadKeyStroke (
    IN  EFI_SIMPLE_TEXT_INPUT_PROTOCOL  *This,
    OUT EFI_INPUT_KEY                   *Key
    )
  {
    EFI_STATUS              Status;
    KEYBOARD_CONSOLE_IN_DEV *ConsoleIn;
    EFI_KEY_DATA            KeyData;
  
    ConsoleIn = KEYBOARD_CONSOLE_IN_DEV_FROM_THIS (This);
    
    //
    // Considering if the partial keystroke is enabled, there maybe a partial
    // keystroke in the queue, so here skip the partial keystroke and get the
    // next key from the queue
    //
    while (1) {
      //
      // If there is no pending key, then return.
      //
      Status = KeyboardReadKeyStrokeWorker (ConsoleIn, &KeyData);
      if (EFI_ERROR(Status)) {
        return Status;
      }
      //
      // If it is partial keystroke, skip it.
      //
      if (KeyData.Key.ScanCode == SCAN_NULL && KeyData.Key.UnicodeChar == CHAR_NULL) {
        continue;
      }
      //
      // Translate the CTRL-Alpha characters to their corresponding control value
      // (ctrl-a = 0x0001 through ctrl-Z = 0x001A)
      //
      if ((KeyData.KeyState.KeyShiftState & (EFI_LEFT_CONTROL_PRESSED | EFI_RIGHT_CONTROL_PRESSED)) != 0) {
        if (KeyData.Key.UnicodeChar >= L'a' && KeyData.Key.UnicodeChar <= L'z') {
          KeyData.Key.UnicodeChar = (CHAR16) (KeyData.Key.UnicodeChar - L'a' + 1);
        } else if (KeyData.Key.UnicodeChar >= L'A' && KeyData.Key.UnicodeChar <= L'Z') {
          KeyData.Key.UnicodeChar = (CHAR16) (KeyData.Key.UnicodeChar - L'A' + 1);
        }
      }
  
      CopyMem(Key, &KeyData.Key, sizeof (EFI_INPUT_KEY));
      return EFI_SUCCESS;
    }
  }
  
  /**
    Event notification function for SIMPLE_TEXT_IN.WaitForKey event
    Signal the event if there is key available
  
    @param Event    the event object
    @param Context  waitting context
  
  **/
  VOID
  EFIAPI
  KeyboardWaitForKey (
    IN  EFI_EVENT               Event,
    IN  VOID                    *Context
    )
  {
    EFI_TPL                     OldTpl;
    KEYBOARD_CONSOLE_IN_DEV     *ConsoleIn;
    EFI_KEY_DATA                KeyData;
  
    ConsoleIn = (KEYBOARD_CONSOLE_IN_DEV *) Context;
  
    //
    // Enter critical section
    //
    OldTpl = gBS->RaiseTPL (TPL_NOTIFY);
  
    KeyboardTimerHandler (NULL, ConsoleIn);
  
    if (!ConsoleIn->KeyboardErr) {
      //
      // WaitforKey doesn't suppor the partial key.
      // Considering if the partial keystroke is enabled, there maybe a partial
      // keystroke in the queue, so here skip the partial keystroke and get the
      // next key from the queue
      //
      while (!IsEfikeyBufEmpty (&ConsoleIn->EfiKeyQueue)) {
        CopyMem(
          &KeyData,
          &(ConsoleIn->EfiKeyQueue.Buffer[ConsoleIn->EfiKeyQueue.Head]),
          sizeof (EFI_KEY_DATA)
          );
        if (KeyData.Key.ScanCode == SCAN_NULL && KeyData.Key.UnicodeChar == CHAR_NULL) {
          PopEfikeyBufHead (&ConsoleIn->EfiKeyQueue, &KeyData);
          continue;
        }
        //
        // if there is pending value key, signal the event.
        //
        gBS->SignalEvent (Event);
        break;
      }
    }
    //
    // Leave critical section and return
    //
    gBS->RestoreTPL (OldTpl);
  }
  
  /**
    Event notification function for SIMPLE_TEXT_INPUT_EX_PROTOCOL.WaitForKeyEx event
    Signal the event if there is key available
  
    @param Event    event object
    @param Context  waiting context
  
  **/
  VOID
  EFIAPI
  KeyboardWaitForKeyEx (
    IN  EFI_EVENT               Event,
    IN  VOID                    *Context
    )
  
  {
    KeyboardWaitForKey (Event, Context);
  }
  
  /**
    Reset the input device and optionaly run diagnostics
  
    @param This                     Protocol instance pointer.
    @param ExtendedVerification     Driver may perform diagnostics on reset.
  
    @retval EFI_SUCCESS             The device was reset.
    @retval EFI_DEVICE_ERROR        The device is not functioning properly and could
                                    not be reset.
  
  **/
  EFI_STATUS
  EFIAPI
  KeyboardEfiResetEx (
    IN EFI_SIMPLE_TEXT_INPUT_EX_PROTOCOL  *This,
    IN BOOLEAN                            ExtendedVerification
    )
  
  {
    KEYBOARD_CONSOLE_IN_DEV               *ConsoleInDev;
  
    ConsoleInDev = TEXT_INPUT_EX_KEYBOARD_CONSOLE_IN_DEV_FROM_THIS (This);
  
    return ConsoleInDev->ConIn.Reset (
                                 &ConsoleInDev->ConIn,
                                 ExtendedVerification
                                 );
  }
  
  /**
      Reads the next keystroke from the input device. The WaitForKey Event can
      be used to test for existance of a keystroke via WaitForEvent () call.
  
  
      @param This         Protocol instance pointer.
      @param KeyData      A pointer to a buffer that is filled in with the keystroke
                          state data for the key that was pressed.
  
      @retval EFI_SUCCESS           The keystroke information was returned.
      @retval EFI_NOT_READY         There was no keystroke data availiable.
      @retval EFI_DEVICE_ERROR      The keystroke information was not returned due to
                                    hardware errors.
      @retval EFI_INVALID_PARAMETER KeyData is NULL.
  
  **/
  EFI_STATUS
  EFIAPI
  KeyboardReadKeyStrokeEx (
    IN  EFI_SIMPLE_TEXT_INPUT_EX_PROTOCOL *This,
    OUT EFI_KEY_DATA                      *KeyData
    )
  
  {
    KEYBOARD_CONSOLE_IN_DEV               *ConsoleInDev;
  
    if (KeyData == NULL) {
      return EFI_INVALID_PARAMETER;
    }
  
    ConsoleInDev = TEXT_INPUT_EX_KEYBOARD_CONSOLE_IN_DEV_FROM_THIS (This);
    return KeyboardReadKeyStrokeWorker (ConsoleInDev, KeyData);
  }
  
  /**
    Set certain state for the input device.
  
    @param This               Protocol instance pointer.
    @param KeyToggleState     A pointer to the EFI_KEY_TOGGLE_STATE to set the
                              state for the input device.
  
    @retval EFI_SUCCESS           The device state was set successfully.
    @retval EFI_DEVICE_ERROR      The device is not functioning correctly and could
                                  not have the setting adjusted.
    @retval EFI_UNSUPPORTED       The device does not have the ability to set its state.
    @retval EFI_INVALID_PARAMETER KeyToggleState is NULL.
  
  **/
  EFI_STATUS
  EFIAPI
  KeyboardSetState (
    IN EFI_SIMPLE_TEXT_INPUT_EX_PROTOCOL  *This,
    IN EFI_KEY_TOGGLE_STATE               *KeyToggleState
    )
  
  {
    EFI_STATUS                            Status;
    KEYBOARD_CONSOLE_IN_DEV               *ConsoleInDev;
    EFI_TPL                               OldTpl;
  
    if (KeyToggleState == NULL) {
      return EFI_INVALID_PARAMETER;
    }
  
    ConsoleInDev = TEXT_INPUT_EX_KEYBOARD_CONSOLE_IN_DEV_FROM_THIS (This);
  
    //
    // Enter critical section
    //
    OldTpl = gBS->RaiseTPL (TPL_NOTIFY);
  
    if (ConsoleInDev->KeyboardErr) {
      Status = EFI_DEVICE_ERROR;
      goto Exit;
    }
  
    if ((*KeyToggleState & EFI_TOGGLE_STATE_VALID) != EFI_TOGGLE_STATE_VALID) {
      Status = EFI_UNSUPPORTED;
      goto Exit;
    }
  
    //
    // Update the status light
    //
    ConsoleInDev->ScrollLock          = FALSE;
    ConsoleInDev->NumLock             = FALSE;
    ConsoleInDev->CapsLock            = FALSE;
    ConsoleInDev->IsSupportPartialKey = FALSE;
  
    if ((*KeyToggleState & EFI_SCROLL_LOCK_ACTIVE) == EFI_SCROLL_LOCK_ACTIVE) {
      ConsoleInDev->ScrollLock = TRUE;
    }
    if ((*KeyToggleState & EFI_NUM_LOCK_ACTIVE) == EFI_NUM_LOCK_ACTIVE) {
      ConsoleInDev->NumLock = TRUE;
    }
    if ((*KeyToggleState & EFI_CAPS_LOCK_ACTIVE) == EFI_CAPS_LOCK_ACTIVE) {
      ConsoleInDev->CapsLock = TRUE;
    }
    if ((*KeyToggleState & EFI_KEY_STATE_EXPOSED) == EFI_KEY_STATE_EXPOSED) {
      ConsoleInDev->IsSupportPartialKey = TRUE;
    }
  
    Status = UpdateStatusLights (ConsoleInDev);
    if (EFI_ERROR(Status)) {
      Status = EFI_DEVICE_ERROR;
    }
  
  Exit:
    //
    // Leave critical section and return
    //
    gBS->RestoreTPL (OldTpl);
  
    return Status;
  
  }
  
  /**
      Register a notification function for a particular keystroke for the input device.
  
      @param This                       Protocol instance pointer.
      @param KeyData                    A pointer to a buffer that is filled in with the keystroke
                                        information data for the key that was pressed. If KeyData.Key,
                                        KeyData.KeyState.KeyToggleState and KeyData.KeyState.KeyShiftState
                                        are 0, then any incomplete keystroke will trigger a notification of
                                        the KeyNotificationFunction.
      @param KeyNotificationFunction    Points to the function to be called when the key
                                        sequence is typed specified by KeyData. This notification function
                                        should be called at <=TPL_CALLBACK.
      @param NotifyHandle               Points to the unique handle assigned to the registered notification.
  
      @retval EFI_SUCCESS               The notification function was registered successfully.
      @retval EFI_OUT_OF_RESOURCES      Unable to allocate resources for necesssary data structures.
      @retval EFI_INVALID_PARAMETER     KeyData or NotifyHandle or KeyNotificationFunction is NULL.
  
  **/
  EFI_STATUS
  EFIAPI
  KeyboardRegisterKeyNotify (
    IN EFI_SIMPLE_TEXT_INPUT_EX_PROTOCOL  *This,
    IN EFI_KEY_DATA                       *KeyData,
    IN EFI_KEY_NOTIFY_FUNCTION            KeyNotificationFunction,
    OUT VOID                              **NotifyHandle
    )
  {
    EFI_STATUS                            Status;
    KEYBOARD_CONSOLE_IN_DEV               *ConsoleInDev;
    EFI_TPL                               OldTpl;
    LIST_ENTRY                            *Link;
    KEYBOARD_CONSOLE_IN_EX_NOTIFY         *CurrentNotify;
    KEYBOARD_CONSOLE_IN_EX_NOTIFY         *NewNotify;
  
    if (KeyData == NULL || NotifyHandle == NULL || KeyNotificationFunction == NULL) {
      return EFI_INVALID_PARAMETER;
    }
  
    ConsoleInDev = TEXT_INPUT_EX_KEYBOARD_CONSOLE_IN_DEV_FROM_THIS (This);
  
    //
    // Enter critical section
    //
    OldTpl = gBS->RaiseTPL (TPL_NOTIFY);
  
    //
    // Return EFI_SUCCESS if the (KeyData, NotificationFunction) is already registered.
    //
    for (Link = ConsoleInDev->NotifyList.ForwardLink; Link != &ConsoleInDev->NotifyList; Link = Link->ForwardLink) {
      CurrentNotify = CR (
                        Link,
                        KEYBOARD_CONSOLE_IN_EX_NOTIFY,
                        NotifyEntry,
                        KEYBOARD_CONSOLE_IN_EX_NOTIFY_SIGNATURE
                        );
      if (IsKeyRegistered (&CurrentNotify->KeyData, KeyData)) {
        if (CurrentNotify->KeyNotificationFn == KeyNotificationFunction) {
          *NotifyHandle = CurrentNotify;
          Status = EFI_SUCCESS;
          goto Exit;
        }
      }
    }
  
    //
    // Allocate resource to save the notification function
    //
    NewNotify = (KEYBOARD_CONSOLE_IN_EX_NOTIFY *) AllocateZeroPool(sizeof (KEYBOARD_CONSOLE_IN_EX_NOTIFY));
    if (NewNotify == NULL) {
      Status = EFI_OUT_OF_RESOURCES;
      goto Exit;
    }
  
    NewNotify->Signature         = KEYBOARD_CONSOLE_IN_EX_NOTIFY_SIGNATURE;
    NewNotify->KeyNotificationFn = KeyNotificationFunction;
    CopyMem(&NewNotify->KeyData, KeyData, sizeof (EFI_KEY_DATA));
    InsertTailList (&ConsoleInDev->NotifyList, &NewNotify->NotifyEntry);
  
    *NotifyHandle                = NewNotify;
    Status                       = EFI_SUCCESS;
  
  Exit:
    //
    // Leave critical section and return
    //
    gBS->RestoreTPL (OldTpl);
    return Status;
  
  }
  
  /**
      Remove a registered notification function from a particular keystroke.
  
      @param This                       Protocol instance pointer.
      @param NotificationHandle         The handle of the notification function being unregistered.
  
  
      @retval EFI_SUCCESS               The notification function was unregistered successfully.
      @retval EFI_INVALID_PARAMETER     The NotificationHandle is invalid.
  
  **/
  EFI_STATUS
  EFIAPI
  KeyboardUnregisterKeyNotify (
    IN EFI_SIMPLE_TEXT_INPUT_EX_PROTOCOL  *This,
    IN VOID                               *NotificationHandle
    )
  {
    EFI_STATUS                            Status;
    KEYBOARD_CONSOLE_IN_DEV               *ConsoleInDev;
    EFI_TPL                               OldTpl;
    LIST_ENTRY                            *Link;
    KEYBOARD_CONSOLE_IN_EX_NOTIFY         *CurrentNotify;
  
    if (NotificationHandle == NULL) {
      return EFI_INVALID_PARAMETER;
    }
  
    ConsoleInDev = TEXT_INPUT_EX_KEYBOARD_CONSOLE_IN_DEV_FROM_THIS (This);
  
    //
    // Enter critical section
    //
    OldTpl = gBS->RaiseTPL (TPL_NOTIFY);
  
    for (Link = ConsoleInDev->NotifyList.ForwardLink; Link != &ConsoleInDev->NotifyList; Link = Link->ForwardLink) {
      CurrentNotify = CR (
                        Link,
                        KEYBOARD_CONSOLE_IN_EX_NOTIFY,
                        NotifyEntry,
                        KEYBOARD_CONSOLE_IN_EX_NOTIFY_SIGNATURE
                        );
      if (CurrentNotify == NotificationHandle) {
        //
        // Remove the notification function from NotifyList and free resources
        //
        RemoveEntryList (&CurrentNotify->NotifyEntry);
  
        gBS->FreePool(CurrentNotify);
        Status = EFI_SUCCESS;
        goto Exit;
      }
    }
  
    //
    // Can not find the specified Notification Handle
    //
    Status = EFI_INVALID_PARAMETER;
  Exit:
    //
    // Leave critical section and return
    //
    gBS->RestoreTPL (OldTpl);
    return Status;
  }
  
  /**
    Process key notify.
  
    @param  Event                 Indicates the event that invoke this function.
    @param  Context               Indicates the calling context.
  **/
  VOID
  EFIAPI
  KeyNotifyProcessHandler (
    IN  EFI_EVENT                 Event,
    IN  VOID                      *Context
    )
  {
    EFI_STATUS                    Status;
    KEYBOARD_CONSOLE_IN_DEV       *ConsoleIn;
    EFI_KEY_DATA                  KeyData;
    LIST_ENTRY                    *Link;
    LIST_ENTRY                    *NotifyList;
    KEYBOARD_CONSOLE_IN_EX_NOTIFY *CurrentNotify;
    EFI_TPL                       OldTpl;
  
    ConsoleIn = (KEYBOARD_CONSOLE_IN_DEV *) Context;
  
    //
    // Invoke notification functions.
    //
    NotifyList = &ConsoleIn->NotifyList;
    while (TRUE) {
      //
      // Enter critical section
      //  
      OldTpl = gBS->RaiseTPL (TPL_NOTIFY);
      Status = PopEfikeyBufHead (&ConsoleIn->EfiKeyQueueForNotify, &KeyData);
      //
      // Leave critical section
      //
      gBS->RestoreTPL (OldTpl);
      if (EFI_ERROR(Status)) {
        break;
      }
      for (Link = GetFirstNode (NotifyList); !IsNull (NotifyList, Link); Link = GetNextNode (NotifyList, Link)) {
        CurrentNotify = CR (Link, KEYBOARD_CONSOLE_IN_EX_NOTIFY, NotifyEntry, KEYBOARD_CONSOLE_IN_EX_NOTIFY_SIGNATURE);
        if (IsKeyRegistered (&CurrentNotify->KeyData, &KeyData)) {
          CurrentNotify->KeyNotificationFn (&KeyData);
        }
      }
    }
  }
  
  