/** @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>
SPDX-License-Identifier: BSD-2-Clause-Patent

**/

#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 registered 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 FALSE               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 existence 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 available.
    @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
  @retval EFI_UNSUPPORTED  The device does not support the ability to read keystroke data.
**/
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  waiting 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 support 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 optionally 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 existence 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 available.
    @retval EFI_DEVICE_ERROR      The keystroke information was not returned due to
                                  hardware errors.
    @retval EFI_INVALID_PARAMETER KeyData is NULL.
    @retval EFI_UNSUPPORTED       The device does not support the ability to read keystroke data.

**/
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 necessary 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);
      }
    }
  }
}