audk/OvmfPkg/Library/PlatformBootManagerLib/BdsPlatform.c

/** @file
  Platform BDS customizations.

  Copyright (c) 2004 - 2018, Intel Corporation. All rights reserved.<BR>
  SPDX-License-Identifier: BSD-2-Clause-Patent

**/

#include "BdsPlatform.h"
#include <Guid/XenInfo.h>
#include <Guid/RootBridgesConnectedEventGroup.h>
#include <Protocol/FirmwareVolume2.h>
#include <Library/PlatformBmPrintScLib.h>
#include <Library/Tcg2PhysicalPresenceLib.h>


//
// Global data
//

VOID          *mEfiDevPathNotifyReg;
EFI_EVENT     mEfiDevPathEvent;
VOID          *mEmuVariableEventReg;
EFI_EVENT     mEmuVariableEvent;
UINT16        mHostBridgeDevId;

//
// Table of host IRQs matching PCI IRQs A-D
// (for configuring PCI Interrupt Line register)
//
CONST UINT8 PciHostIrqs[] = {
  0x0a, 0x0a, 0x0b, 0x0b
};

//
// Type definitions
//

typedef
EFI_STATUS
(EFIAPI *PROTOCOL_INSTANCE_CALLBACK)(
  IN EFI_HANDLE           Handle,
  IN VOID                 *Instance,
  IN VOID                 *Context
  );

/**
  @param[in]  Handle - Handle of PCI device instance
  @param[in]  PciIo - PCI IO protocol instance
  @param[in]  Pci - PCI Header register block
**/
typedef
EFI_STATUS
(EFIAPI *VISIT_PCI_INSTANCE_CALLBACK)(
  IN EFI_HANDLE           Handle,
  IN EFI_PCI_IO_PROTOCOL  *PciIo,
  IN PCI_TYPE00           *Pci
  );


//
// Function prototypes
//

EFI_STATUS
VisitAllInstancesOfProtocol (
  IN EFI_GUID                    *Id,
  IN PROTOCOL_INSTANCE_CALLBACK  CallBackFunction,
  IN VOID                        *Context
  );

EFI_STATUS
VisitAllPciInstancesOfProtocol (
  IN VISIT_PCI_INSTANCE_CALLBACK CallBackFunction
  );

VOID
InstallDevicePathCallback (
  VOID
  );

VOID
PlatformRegisterFvBootOption (
  EFI_GUID                         *FileGuid,
  CHAR16                           *Description,
  UINT32                           Attributes
  )
{
  EFI_STATUS                        Status;
  INTN                              OptionIndex;
  EFI_BOOT_MANAGER_LOAD_OPTION      NewOption;
  EFI_BOOT_MANAGER_LOAD_OPTION      *BootOptions;
  UINTN                             BootOptionCount;
  MEDIA_FW_VOL_FILEPATH_DEVICE_PATH FileNode;
  EFI_LOADED_IMAGE_PROTOCOL         *LoadedImage;
  EFI_DEVICE_PATH_PROTOCOL          *DevicePath;

  Status = gBS->HandleProtocol (
                  gImageHandle,
                  &gEfiLoadedImageProtocolGuid,
                  (VOID **) &LoadedImage
                  );
  ASSERT_EFI_ERROR (Status);

  EfiInitializeFwVolDevicepathNode (&FileNode, FileGuid);
  DevicePath = DevicePathFromHandle (LoadedImage->DeviceHandle);
  ASSERT (DevicePath != NULL);
  DevicePath = AppendDevicePathNode (
                 DevicePath,
                 (EFI_DEVICE_PATH_PROTOCOL *) &FileNode
                 );
  ASSERT (DevicePath != NULL);

  Status = EfiBootManagerInitializeLoadOption (
             &NewOption,
             LoadOptionNumberUnassigned,
             LoadOptionTypeBoot,
             Attributes,
             Description,
             DevicePath,
             NULL,
             0
             );
  ASSERT_EFI_ERROR (Status);
  FreePool (DevicePath);

  BootOptions = EfiBootManagerGetLoadOptions (
                  &BootOptionCount, LoadOptionTypeBoot
                  );

  OptionIndex = EfiBootManagerFindLoadOption (
                  &NewOption, BootOptions, BootOptionCount
                  );

  if (OptionIndex == -1) {
    Status = EfiBootManagerAddLoadOptionVariable (&NewOption, MAX_UINTN);
    ASSERT_EFI_ERROR (Status);
  }
  EfiBootManagerFreeLoadOption (&NewOption);
  EfiBootManagerFreeLoadOptions (BootOptions, BootOptionCount);
}

/**
  Remove all MemoryMapped(...)/FvFile(...) and Fv(...)/FvFile(...) boot options
  whose device paths do not resolve exactly to an FvFile in the system.

  This removes any boot options that point to binaries built into the firmware
  and have become stale due to any of the following:
  - DXEFV's base address or size changed (historical),
  - DXEFV's FvNameGuid changed,
  - the FILE_GUID of the pointed-to binary changed,
  - the referenced binary is no longer built into the firmware.

  EfiBootManagerFindLoadOption() used in PlatformRegisterFvBootOption() only
  avoids exact duplicates.
**/
VOID
RemoveStaleFvFileOptions (
  VOID
  )
{
  EFI_BOOT_MANAGER_LOAD_OPTION *BootOptions;
  UINTN                        BootOptionCount;
  UINTN                        Index;

  BootOptions = EfiBootManagerGetLoadOptions (&BootOptionCount,
                  LoadOptionTypeBoot);

  for (Index = 0; Index < BootOptionCount; ++Index) {
    EFI_DEVICE_PATH_PROTOCOL *Node1, *Node2, *SearchNode;
    EFI_STATUS               Status;
    EFI_HANDLE               FvHandle;

    //
    // If the device path starts with neither MemoryMapped(...) nor Fv(...),
    // then keep the boot option.
    //
    Node1 = BootOptions[Index].FilePath;
    if (!(DevicePathType (Node1) == HARDWARE_DEVICE_PATH &&
          DevicePathSubType (Node1) == HW_MEMMAP_DP) &&
        !(DevicePathType (Node1) == MEDIA_DEVICE_PATH &&
          DevicePathSubType (Node1) == MEDIA_PIWG_FW_VOL_DP)) {
      continue;
    }

    //
    // If the second device path node is not FvFile(...), then keep the boot
    // option.
    //
    Node2 = NextDevicePathNode (Node1);
    if (DevicePathType (Node2) != MEDIA_DEVICE_PATH ||
        DevicePathSubType (Node2) != MEDIA_PIWG_FW_FILE_DP) {
      continue;
    }

    //
    // Locate the Firmware Volume2 protocol instance that is denoted by the
    // boot option. If this lookup fails (i.e., the boot option references a
    // firmware volume that doesn't exist), then we'll proceed to delete the
    // boot option.
    //
    SearchNode = Node1;
    Status = gBS->LocateDevicePath (&gEfiFirmwareVolume2ProtocolGuid,
                    &SearchNode, &FvHandle);

    if (!EFI_ERROR (Status)) {
      //
      // The firmware volume was found; now let's see if it contains the FvFile
      // identified by GUID.
      //
      EFI_FIRMWARE_VOLUME2_PROTOCOL     *FvProtocol;
      MEDIA_FW_VOL_FILEPATH_DEVICE_PATH *FvFileNode;
      UINTN                             BufferSize;
      EFI_FV_FILETYPE                   FoundType;
      EFI_FV_FILE_ATTRIBUTES            FileAttributes;
      UINT32                            AuthenticationStatus;

      Status = gBS->HandleProtocol (FvHandle, &gEfiFirmwareVolume2ProtocolGuid,
                      (VOID **)&FvProtocol);
      ASSERT_EFI_ERROR (Status);

      FvFileNode = (MEDIA_FW_VOL_FILEPATH_DEVICE_PATH *)Node2;
      //
      // Buffer==NULL means we request metadata only: BufferSize, FoundType,
      // FileAttributes.
      //
      Status = FvProtocol->ReadFile (
                             FvProtocol,
                             &FvFileNode->FvFileName, // NameGuid
                             NULL,                    // Buffer
                             &BufferSize,
                             &FoundType,
                             &FileAttributes,
                             &AuthenticationStatus
                             );
      if (!EFI_ERROR (Status)) {
        //
        // The FvFile was found. Keep the boot option.
        //
        continue;
      }
    }

    //
    // Delete the boot option.
    //
    Status = EfiBootManagerDeleteLoadOptionVariable (
               BootOptions[Index].OptionNumber, LoadOptionTypeBoot);
    DEBUG_CODE (
      CHAR16 *DevicePathString;

      DevicePathString = ConvertDevicePathToText(BootOptions[Index].FilePath,
                           FALSE, FALSE);
      DEBUG ((
        EFI_ERROR (Status) ? EFI_D_WARN : EFI_D_VERBOSE,
        "%a: removing stale Boot#%04x %s: %r\n",
        __FUNCTION__,
        (UINT32)BootOptions[Index].OptionNumber,
        DevicePathString == NULL ? L"<unavailable>" : DevicePathString,
        Status
        ));
      if (DevicePathString != NULL) {
        FreePool (DevicePathString);
      }
      );
  }

  EfiBootManagerFreeLoadOptions (BootOptions, BootOptionCount);
}

VOID
PlatformRegisterOptionsAndKeys (
  VOID
  )
{
  EFI_STATUS                   Status;
  EFI_INPUT_KEY                Enter;
  EFI_INPUT_KEY                F2;
  EFI_INPUT_KEY                Esc;
  EFI_BOOT_MANAGER_LOAD_OPTION BootOption;

  //
  // Register ENTER as CONTINUE key
  //
  Enter.ScanCode    = SCAN_NULL;
  Enter.UnicodeChar = CHAR_CARRIAGE_RETURN;
  Status = EfiBootManagerRegisterContinueKeyOption (0, &Enter, NULL);
  ASSERT_EFI_ERROR (Status);

  //
  // Map F2 to Boot Manager Menu
  //
  F2.ScanCode     = SCAN_F2;
  F2.UnicodeChar  = CHAR_NULL;
  Esc.ScanCode    = SCAN_ESC;
  Esc.UnicodeChar = CHAR_NULL;
  Status = EfiBootManagerGetBootManagerMenu (&BootOption);
  ASSERT_EFI_ERROR (Status);
  Status = EfiBootManagerAddKeyOptionVariable (
             NULL, (UINT16) BootOption.OptionNumber, 0, &F2, NULL
             );
  ASSERT (Status == EFI_SUCCESS || Status == EFI_ALREADY_STARTED);
  Status = EfiBootManagerAddKeyOptionVariable (
             NULL, (UINT16) BootOption.OptionNumber, 0, &Esc, NULL
             );
  ASSERT (Status == EFI_SUCCESS || Status == EFI_ALREADY_STARTED);
}

EFI_STATUS
EFIAPI
ConnectRootBridge (
  IN EFI_HANDLE  RootBridgeHandle,
  IN VOID        *Instance,
  IN VOID        *Context
  );

STATIC
EFI_STATUS
EFIAPI
ConnectVirtioPciRng (
  IN EFI_HANDLE Handle,
  IN VOID       *Instance,
  IN VOID       *Context
  );

STATIC
VOID
SaveS3BootScript (
  VOID
  );

//
// BDS Platform Functions
//
/**
  Do the platform init, can be customized by OEM/IBV

  Possible things that can be done in PlatformBootManagerBeforeConsole:

  > Update console variable: 1. include hot-plug devices;
  >                          2. Clear ConIn and add SOL for AMT
  > Register new Driver#### or Boot####
  > Register new Key####: e.g.: F12
  > Signal ReadyToLock event
  > Authentication action: 1. connect Auth devices;
  >                        2. Identify auto logon user.
**/
VOID
EFIAPI
PlatformBootManagerBeforeConsole (
  VOID
  )
{
  EFI_HANDLE    Handle;
  EFI_STATUS    Status;
  RETURN_STATUS PcdStatus;

  DEBUG ((EFI_D_INFO, "PlatformBootManagerBeforeConsole\n"));
  InstallDevicePathCallback ();

  VisitAllInstancesOfProtocol (&gEfiPciRootBridgeIoProtocolGuid,
    ConnectRootBridge, NULL);

  //
  // Signal the ACPI platform driver that it can download QEMU ACPI tables.
  //
  EfiEventGroupSignal (&gRootBridgesConnectedEventGroupGuid);

  //
  // We can't signal End-of-Dxe earlier than this. Namely, End-of-Dxe triggers
  // the preparation of S3 system information. That logic has a hard dependency
  // on the presence of the FACS ACPI table. Since our ACPI tables are only
  // installed after PCI enumeration completes, we must not trigger the S3 save
  // earlier, hence we can't signal End-of-Dxe earlier.
  //
  EfiEventGroupSignal (&gEfiEndOfDxeEventGroupGuid);

  if (QemuFwCfgS3Enabled ()) {
    //
    // Save the boot script too. Note that this will require us to emit the
    // DxeSmmReadyToLock event just below, which in turn locks down SMM.
    //
    SaveS3BootScript ();
  }

  //
  // Prevent further changes to LockBoxes or SMRAM.
  //
  Handle = NULL;
  Status = gBS->InstallProtocolInterface (&Handle,
                  &gEfiDxeSmmReadyToLockProtocolGuid, EFI_NATIVE_INTERFACE,
                  NULL);
  ASSERT_EFI_ERROR (Status);

  //
  // Dispatch deferred images after EndOfDxe event and ReadyToLock
  // installation.
  //
  EfiBootManagerDispatchDeferredImages ();

  PlatformInitializeConsole (gPlatformConsole);
  PcdStatus = PcdSet16S (PcdPlatformBootTimeOut,
                GetFrontPageTimeoutFromQemu ());
  ASSERT_RETURN_ERROR (PcdStatus);

  PlatformRegisterOptionsAndKeys ();

  //
  // Install both VIRTIO_DEVICE_PROTOCOL and (dependent) EFI_RNG_PROTOCOL
  // instances on Virtio PCI RNG devices.
  //
  VisitAllInstancesOfProtocol (&gEfiPciIoProtocolGuid, ConnectVirtioPciRng,
    NULL);
}


EFI_STATUS
EFIAPI
ConnectRootBridge (
  IN EFI_HANDLE  RootBridgeHandle,
  IN VOID        *Instance,
  IN VOID        *Context
  )
{
  EFI_STATUS Status;

  //
  // Make the PCI bus driver connect the root bridge, non-recursively. This
  // will produce a number of child handles with PciIo on them.
  //
  Status = gBS->ConnectController (
                  RootBridgeHandle, // ControllerHandle
                  NULL,             // DriverImageHandle
                  NULL,             // RemainingDevicePath -- produce all
                                    //   children
                  FALSE             // Recursive
                  );
  return Status;
}


STATIC
EFI_STATUS
EFIAPI
ConnectVirtioPciRng (
  IN EFI_HANDLE Handle,
  IN VOID       *Instance,
  IN VOID       *Context
  )
{
  EFI_PCI_IO_PROTOCOL *PciIo;
  EFI_STATUS          Status;
  UINT16              VendorId;
  UINT16              DeviceId;
  UINT8               RevisionId;
  BOOLEAN             Virtio10;
  UINT16              SubsystemId;

  PciIo = Instance;

  //
  // Read and check VendorId.
  //
  Status = PciIo->Pci.Read (PciIo, EfiPciIoWidthUint16, PCI_VENDOR_ID_OFFSET,
                        1, &VendorId);
  if (EFI_ERROR (Status)) {
    goto Error;
  }
  if (VendorId != VIRTIO_VENDOR_ID) {
    return EFI_SUCCESS;
  }

  //
  // Read DeviceId and RevisionId.
  //
  Status = PciIo->Pci.Read (PciIo, EfiPciIoWidthUint16, PCI_DEVICE_ID_OFFSET,
                        1, &DeviceId);
  if (EFI_ERROR (Status)) {
    goto Error;
  }
  Status = PciIo->Pci.Read (PciIo, EfiPciIoWidthUint8, PCI_REVISION_ID_OFFSET,
                        1, &RevisionId);
  if (EFI_ERROR (Status)) {
    goto Error;
  }

  //
  // From DeviceId and RevisionId, determine whether the device is a
  // modern-only Virtio 1.0 device. In case of Virtio 1.0, DeviceId can
  // immediately be restricted to VIRTIO_SUBSYSTEM_ENTROPY_SOURCE, and
  // SubsystemId will only play a sanity-check role. Otherwise, DeviceId can
  // only be sanity-checked, and SubsystemId will decide.
  //
  if (DeviceId == 0x1040 + VIRTIO_SUBSYSTEM_ENTROPY_SOURCE &&
      RevisionId >= 0x01) {
    Virtio10 = TRUE;
  } else if (DeviceId >= 0x1000 && DeviceId <= 0x103F && RevisionId == 0x00) {
    Virtio10 = FALSE;
  } else {
    return EFI_SUCCESS;
  }

  //
  // Read and check SubsystemId as dictated by Virtio10.
  //
  Status = PciIo->Pci.Read (PciIo, EfiPciIoWidthUint16,
                        PCI_SUBSYSTEM_ID_OFFSET, 1, &SubsystemId);
  if (EFI_ERROR (Status)) {
    goto Error;
  }
  if ((Virtio10 && SubsystemId >= 0x40) ||
      (!Virtio10 && SubsystemId == VIRTIO_SUBSYSTEM_ENTROPY_SOURCE)) {
    Status = gBS->ConnectController (
                    Handle, // ControllerHandle
                    NULL,   // DriverImageHandle -- connect all drivers
                    NULL,   // RemainingDevicePath -- produce all child handles
                    FALSE   // Recursive -- don't follow child handles
                    );
    if (EFI_ERROR (Status)) {
      goto Error;
    }
  }
  return EFI_SUCCESS;

Error:
  DEBUG ((DEBUG_ERROR, "%a: %r\n", __FUNCTION__, Status));
  return Status;
}


/**
  Add IsaKeyboard to ConIn; add IsaSerial to ConOut, ConIn, ErrOut.

  @param[in] DeviceHandle  Handle of the LPC Bridge device.

  @retval EFI_SUCCESS  Console devices on the LPC bridge have been added to
                       ConOut, ConIn, and ErrOut.

  @return              Error codes, due to EFI_DEVICE_PATH_PROTOCOL missing
                       from DeviceHandle.
**/
EFI_STATUS
PrepareLpcBridgeDevicePath (
  IN EFI_HANDLE                DeviceHandle
  )
{
  EFI_STATUS                Status;
  EFI_DEVICE_PATH_PROTOCOL  *DevicePath;
  EFI_DEVICE_PATH_PROTOCOL  *TempDevicePath;
  CHAR16                    *DevPathStr;

  DevicePath = NULL;
  Status = gBS->HandleProtocol (
                  DeviceHandle,
                  &gEfiDevicePathProtocolGuid,
                  (VOID*)&DevicePath
                  );
  if (EFI_ERROR (Status)) {
    return Status;
  }
  TempDevicePath = DevicePath;

  //
  // Register Keyboard
  //
  DevicePath = AppendDevicePathNode (DevicePath,
                 (EFI_DEVICE_PATH_PROTOCOL *)&gPnpPs2KeyboardDeviceNode);

  EfiBootManagerUpdateConsoleVariable (ConIn, DevicePath, NULL);

  //
  // Register COM1
  //
  DevicePath = TempDevicePath;
  gPnp16550ComPortDeviceNode.UID = 0;

  DevicePath = AppendDevicePathNode (DevicePath,
                 (EFI_DEVICE_PATH_PROTOCOL *)&gPnp16550ComPortDeviceNode);
  DevicePath = AppendDevicePathNode (DevicePath,
                 (EFI_DEVICE_PATH_PROTOCOL *)&gUartDeviceNode);
  DevicePath = AppendDevicePathNode (DevicePath,
                 (EFI_DEVICE_PATH_PROTOCOL *)&gTerminalTypeDeviceNode);

  //
  // Print Device Path
  //
  DevPathStr = ConvertDevicePathToText (DevicePath, FALSE, FALSE);
  if (DevPathStr != NULL) {
    DEBUG((
      EFI_D_INFO,
      "BdsPlatform.c+%d: COM%d DevPath: %s\n",
      __LINE__,
      gPnp16550ComPortDeviceNode.UID + 1,
      DevPathStr
      ));
    FreePool(DevPathStr);
  }

  EfiBootManagerUpdateConsoleVariable (ConOut, DevicePath, NULL);
  EfiBootManagerUpdateConsoleVariable (ConIn, DevicePath, NULL);
  EfiBootManagerUpdateConsoleVariable (ErrOut, DevicePath, NULL);

  //
  // Register COM2
  //
  DevicePath = TempDevicePath;
  gPnp16550ComPortDeviceNode.UID = 1;

  DevicePath = AppendDevicePathNode (DevicePath,
                 (EFI_DEVICE_PATH_PROTOCOL *)&gPnp16550ComPortDeviceNode);
  DevicePath = AppendDevicePathNode (DevicePath,
                 (EFI_DEVICE_PATH_PROTOCOL *)&gUartDeviceNode);
  DevicePath = AppendDevicePathNode (DevicePath,
                 (EFI_DEVICE_PATH_PROTOCOL *)&gTerminalTypeDeviceNode);

  //
  // Print Device Path
  //
  DevPathStr = ConvertDevicePathToText (DevicePath, FALSE, FALSE);
  if (DevPathStr != NULL) {
    DEBUG((
      EFI_D_INFO,
      "BdsPlatform.c+%d: COM%d DevPath: %s\n",
      __LINE__,
      gPnp16550ComPortDeviceNode.UID + 1,
      DevPathStr
      ));
    FreePool(DevPathStr);
  }

  EfiBootManagerUpdateConsoleVariable (ConOut, DevicePath, NULL);
  EfiBootManagerUpdateConsoleVariable (ConIn, DevicePath, NULL);
  EfiBootManagerUpdateConsoleVariable (ErrOut, DevicePath, NULL);

  return EFI_SUCCESS;
}

EFI_STATUS
GetGopDevicePath (
   IN  EFI_DEVICE_PATH_PROTOCOL *PciDevicePath,
   OUT EFI_DEVICE_PATH_PROTOCOL **GopDevicePath
   )
{
  UINTN                           Index;
  EFI_STATUS                      Status;
  EFI_HANDLE                      PciDeviceHandle;
  EFI_DEVICE_PATH_PROTOCOL        *TempDevicePath;
  EFI_DEVICE_PATH_PROTOCOL        *TempPciDevicePath;
  UINTN                           GopHandleCount;
  EFI_HANDLE                      *GopHandleBuffer;

  if (PciDevicePath == NULL || GopDevicePath == NULL) {
    return EFI_INVALID_PARAMETER;
  }

  //
  // Initialize the GopDevicePath to be PciDevicePath
  //
  *GopDevicePath    = PciDevicePath;
  TempPciDevicePath = PciDevicePath;

  Status = gBS->LocateDevicePath (
                  &gEfiDevicePathProtocolGuid,
                  &TempPciDevicePath,
                  &PciDeviceHandle
                  );
  if (EFI_ERROR (Status)) {
    return Status;
  }

  //
  // Try to connect this handle, so that GOP driver could start on this
  // device and create child handles with GraphicsOutput Protocol installed
  // on them, then we get device paths of these child handles and select
  // them as possible console device.
  //
  gBS->ConnectController (PciDeviceHandle, NULL, NULL, FALSE);

  Status = gBS->LocateHandleBuffer (
                  ByProtocol,
                  &gEfiGraphicsOutputProtocolGuid,
                  NULL,
                  &GopHandleCount,
                  &GopHandleBuffer
                  );
  if (!EFI_ERROR (Status)) {
    //
    // Add all the child handles as possible Console Device
    //
    for (Index = 0; Index < GopHandleCount; Index++) {
      Status = gBS->HandleProtocol (GopHandleBuffer[Index],
                      &gEfiDevicePathProtocolGuid, (VOID*)&TempDevicePath);
      if (EFI_ERROR (Status)) {
        continue;
      }
      if (CompareMem (
            PciDevicePath,
            TempDevicePath,
            GetDevicePathSize (PciDevicePath) - END_DEVICE_PATH_LENGTH
            ) == 0) {
        //
        // In current implementation, we only enable one of the child handles
        // as console device, i.e. sotre one of the child handle's device
        // path to variable "ConOut"
        // In future, we could select all child handles to be console device
        //

        *GopDevicePath = TempDevicePath;

        //
        // Delete the PCI device's path that added by
        // GetPlugInPciVgaDevicePath(). Add the integrity GOP device path.
        //
        EfiBootManagerUpdateConsoleVariable (ConOutDev, NULL, PciDevicePath);
        EfiBootManagerUpdateConsoleVariable (ConOutDev, TempDevicePath, NULL);
      }
    }
    gBS->FreePool (GopHandleBuffer);
  }

  return EFI_SUCCESS;
}

/**
  Add PCI display to ConOut.

  @param[in] DeviceHandle  Handle of the PCI display device.

  @retval EFI_SUCCESS  The PCI display device has been added to ConOut.

  @return              Error codes, due to EFI_DEVICE_PATH_PROTOCOL missing
                       from DeviceHandle.
**/
EFI_STATUS
PreparePciDisplayDevicePath (
  IN EFI_HANDLE                DeviceHandle
  )
{
  EFI_STATUS                Status;
  EFI_DEVICE_PATH_PROTOCOL  *DevicePath;
  EFI_DEVICE_PATH_PROTOCOL  *GopDevicePath;

  DevicePath    = NULL;
  GopDevicePath = NULL;
  Status = gBS->HandleProtocol (
                  DeviceHandle,
                  &gEfiDevicePathProtocolGuid,
                  (VOID*)&DevicePath
                  );
  if (EFI_ERROR (Status)) {
    return Status;
  }

  GetGopDevicePath (DevicePath, &GopDevicePath);
  DevicePath = GopDevicePath;

  EfiBootManagerUpdateConsoleVariable (ConOut, DevicePath, NULL);

  return EFI_SUCCESS;
}

/**
  Add PCI Serial to ConOut, ConIn, ErrOut.

  @param[in] DeviceHandle  Handle of the PCI serial device.

  @retval EFI_SUCCESS  The PCI serial device has been added to ConOut, ConIn,
                       ErrOut.

  @return              Error codes, due to EFI_DEVICE_PATH_PROTOCOL missing
                       from DeviceHandle.
**/
EFI_STATUS
PreparePciSerialDevicePath (
  IN EFI_HANDLE                DeviceHandle
  )
{
  EFI_STATUS                Status;
  EFI_DEVICE_PATH_PROTOCOL  *DevicePath;

  DevicePath = NULL;
  Status = gBS->HandleProtocol (
                  DeviceHandle,
                  &gEfiDevicePathProtocolGuid,
                  (VOID*)&DevicePath
                  );
  if (EFI_ERROR (Status)) {
    return Status;
  }

  DevicePath = AppendDevicePathNode (DevicePath,
                 (EFI_DEVICE_PATH_PROTOCOL *)&gUartDeviceNode);
  DevicePath = AppendDevicePathNode (DevicePath,
                 (EFI_DEVICE_PATH_PROTOCOL *)&gTerminalTypeDeviceNode);

  EfiBootManagerUpdateConsoleVariable (ConOut, DevicePath, NULL);
  EfiBootManagerUpdateConsoleVariable (ConIn, DevicePath, NULL);
  EfiBootManagerUpdateConsoleVariable (ErrOut, DevicePath, NULL);

  return EFI_SUCCESS;
}

EFI_STATUS
VisitAllInstancesOfProtocol (
  IN EFI_GUID                    *Id,
  IN PROTOCOL_INSTANCE_CALLBACK  CallBackFunction,
  IN VOID                        *Context
  )
{
  EFI_STATUS                Status;
  UINTN                     HandleCount;
  EFI_HANDLE                *HandleBuffer;
  UINTN                     Index;
  VOID                      *Instance;

  //
  // Start to check all the PciIo to find all possible device
  //
  HandleCount = 0;
  HandleBuffer = NULL;
  Status = gBS->LocateHandleBuffer (
                  ByProtocol,
                  Id,
                  NULL,
                  &HandleCount,
                  &HandleBuffer
                  );
  if (EFI_ERROR (Status)) {
    return Status;
  }

  for (Index = 0; Index < HandleCount; Index++) {
    Status = gBS->HandleProtocol (HandleBuffer[Index], Id, &Instance);
    if (EFI_ERROR (Status)) {
      continue;
    }

    Status = (*CallBackFunction) (
               HandleBuffer[Index],
               Instance,
               Context
               );
  }

  gBS->FreePool (HandleBuffer);

  return EFI_SUCCESS;
}


EFI_STATUS
EFIAPI
VisitingAPciInstance (
  IN EFI_HANDLE  Handle,
  IN VOID        *Instance,
  IN VOID        *Context
  )
{
  EFI_STATUS                Status;
  EFI_PCI_IO_PROTOCOL       *PciIo;
  PCI_TYPE00                Pci;

  PciIo = (EFI_PCI_IO_PROTOCOL*) Instance;

  //
  // Check for all PCI device
  //
  Status = PciIo->Pci.Read (
                    PciIo,
                    EfiPciIoWidthUint32,
                    0,
                    sizeof (Pci) / sizeof (UINT32),
                    &Pci
                    );
  if (EFI_ERROR (Status)) {
    return Status;
  }

  return (*(VISIT_PCI_INSTANCE_CALLBACK)(UINTN) Context) (
           Handle,
           PciIo,
           &Pci
           );

}



EFI_STATUS
VisitAllPciInstances (
  IN VISIT_PCI_INSTANCE_CALLBACK CallBackFunction
  )
{
  return VisitAllInstancesOfProtocol (
           &gEfiPciIoProtocolGuid,
           VisitingAPciInstance,
           (VOID*)(UINTN) CallBackFunction
           );
}


/**
  Do platform specific PCI Device check and add them to
  ConOut, ConIn, ErrOut.

  @param[in]  Handle - Handle of PCI device instance
  @param[in]  PciIo - PCI IO protocol instance
  @param[in]  Pci - PCI Header register block

  @retval EFI_SUCCESS - PCI Device check and Console variable update
                        successfully.
  @retval EFI_STATUS - PCI Device check or Console variable update fail.

**/
EFI_STATUS
EFIAPI
DetectAndPreparePlatformPciDevicePath (
  IN EFI_HANDLE           Handle,
  IN EFI_PCI_IO_PROTOCOL  *PciIo,
  IN PCI_TYPE00           *Pci
  )
{
  EFI_STATUS                Status;

  Status = PciIo->Attributes (
    PciIo,
    EfiPciIoAttributeOperationEnable,
    EFI_PCI_DEVICE_ENABLE,
    NULL
    );
  ASSERT_EFI_ERROR (Status);

  //
  // Here we decide whether it is LPC Bridge
  //
  if ((IS_PCI_LPC (Pci)) ||
      ((IS_PCI_ISA_PDECODE (Pci)) &&
       (Pci->Hdr.VendorId == 0x8086) &&
       (Pci->Hdr.DeviceId == 0x7000)
      )
     ) {
    //
    // Add IsaKeyboard to ConIn,
    // add IsaSerial to ConOut, ConIn, ErrOut
    //
    DEBUG ((EFI_D_INFO, "Found LPC Bridge device\n"));
    PrepareLpcBridgeDevicePath (Handle);
    return EFI_SUCCESS;
  }
  //
  // Here we decide which Serial device to enable in PCI bus
  //
  if (IS_PCI_16550SERIAL (Pci)) {
    //
    // Add them to ConOut, ConIn, ErrOut.
    //
    DEBUG ((EFI_D_INFO, "Found PCI 16550 SERIAL device\n"));
    PreparePciSerialDevicePath (Handle);
    return EFI_SUCCESS;
  }

  //
  // Here we decide which display device to enable in PCI bus
  //
  if (IS_PCI_DISPLAY (Pci)) {
    //
    // Add them to ConOut.
    //
    DEBUG ((EFI_D_INFO, "Found PCI display device\n"));
    PreparePciDisplayDevicePath (Handle);
    return EFI_SUCCESS;
  }

  return Status;
}


/**
  Connect the predefined platform default console device.

  Always try to find and enable PCI display devices.

  @param[in] PlatformConsole  Predefined platform default console device array.
**/
VOID
PlatformInitializeConsole (
  IN PLATFORM_CONSOLE_CONNECT_ENTRY   *PlatformConsole
  )
{
  UINTN                              Index;

  //
  // Do platform specific PCI Device check and add them to ConOut, ConIn,
  // ErrOut
  //
  VisitAllPciInstances (DetectAndPreparePlatformPciDevicePath);

  //
  // Have chance to connect the platform default console,
  // the platform default console is the minimum device group
  // the platform should support
  //
  for (Index = 0; PlatformConsole[Index].DevicePath != NULL; ++Index) {
    //
    // Update the console variable with the connect type
    //
    if ((PlatformConsole[Index].ConnectType & CONSOLE_IN) == CONSOLE_IN) {
      EfiBootManagerUpdateConsoleVariable (ConIn,
        PlatformConsole[Index].DevicePath, NULL);
    }
    if ((PlatformConsole[Index].ConnectType & CONSOLE_OUT) == CONSOLE_OUT) {
      EfiBootManagerUpdateConsoleVariable (ConOut,
        PlatformConsole[Index].DevicePath, NULL);
    }
    if ((PlatformConsole[Index].ConnectType & STD_ERROR) == STD_ERROR) {
      EfiBootManagerUpdateConsoleVariable (ErrOut,
        PlatformConsole[Index].DevicePath, NULL);
    }
  }
}


/**
  Configure PCI Interrupt Line register for applicable devices
  Ported from SeaBIOS, src/fw/pciinit.c, *_pci_slot_get_irq()

  @param[in]  Handle - Handle of PCI device instance
  @param[in]  PciIo - PCI IO protocol instance
  @param[in]  PciHdr - PCI Header register block

  @retval EFI_SUCCESS - PCI Interrupt Line register configured successfully.

**/
EFI_STATUS
EFIAPI
SetPciIntLine (
  IN EFI_HANDLE           Handle,
  IN EFI_PCI_IO_PROTOCOL  *PciIo,
  IN PCI_TYPE00           *PciHdr
  )
{
  EFI_DEVICE_PATH_PROTOCOL  *DevPathNode;
  EFI_DEVICE_PATH_PROTOCOL  *DevPath;
  UINTN                     RootSlot;
  UINTN                     Idx;
  UINT8                     IrqLine;
  EFI_STATUS                Status;
  UINT32                    RootBusNumber;

  Status = EFI_SUCCESS;

  if (PciHdr->Device.InterruptPin != 0) {

    DevPathNode = DevicePathFromHandle (Handle);
    ASSERT (DevPathNode != NULL);
    DevPath = DevPathNode;

    RootBusNumber = 0;
    if (DevicePathType (DevPathNode) == ACPI_DEVICE_PATH &&
        DevicePathSubType (DevPathNode) == ACPI_DP &&
        ((ACPI_HID_DEVICE_PATH *)DevPathNode)->HID == EISA_PNP_ID(0x0A03)) {
      RootBusNumber = ((ACPI_HID_DEVICE_PATH *)DevPathNode)->UID;
    }

    //
    // Compute index into PciHostIrqs[] table by walking
    // the device path and adding up all device numbers
    //
    Status = EFI_NOT_FOUND;
    RootSlot = 0;
    Idx = PciHdr->Device.InterruptPin - 1;
    while (!IsDevicePathEnd (DevPathNode)) {
      if (DevicePathType (DevPathNode) == HARDWARE_DEVICE_PATH &&
          DevicePathSubType (DevPathNode) == HW_PCI_DP) {

        Idx += ((PCI_DEVICE_PATH *)DevPathNode)->Device;

        //
        // Unlike SeaBIOS, which starts climbing from the leaf device
        // up toward the root, we traverse the device path starting at
        // the root moving toward the leaf node.
        // The slot number of the top-level parent bridge is needed for
        // Q35 cases with more than 24 slots on the root bus.
        //
        if (Status != EFI_SUCCESS) {
          Status = EFI_SUCCESS;
          RootSlot = ((PCI_DEVICE_PATH *)DevPathNode)->Device;
        }
      }

      DevPathNode = NextDevicePathNode (DevPathNode);
    }
    if (EFI_ERROR (Status)) {
      return Status;
    }
    if (RootBusNumber == 0 && RootSlot == 0) {
      DEBUG((
        EFI_D_ERROR,
        "%a: PCI host bridge (00:00.0) should have no interrupts!\n",
        __FUNCTION__
        ));
      ASSERT (FALSE);
    }

    //
    // Final PciHostIrqs[] index calculation depends on the platform
    // and should match SeaBIOS src/fw/pciinit.c *_pci_slot_get_irq()
    //
    switch (mHostBridgeDevId) {
      case INTEL_82441_DEVICE_ID:
        Idx -= 1;
        break;
      case INTEL_Q35_MCH_DEVICE_ID:
        //
        // SeaBIOS contains the following comment:
        // "Slots 0-24 rotate slot:pin mapping similar to piix above, but
        //  with a different starting index - see q35-acpi-dsdt.dsl.
        //
        //  Slots 25-31 all use LNKA mapping (or LNKE, but A:D = E:H)"
        //
        if (RootSlot > 24) {
          //
          // in this case, subtract back out RootSlot from Idx
          // (SeaBIOS never adds it to begin with, but that would make our
          //  device path traversal loop above too awkward)
          //
          Idx -= RootSlot;
        }
        break;
      default:
        ASSERT (FALSE); // should never get here
    }
    Idx %= ARRAY_SIZE (PciHostIrqs);
    IrqLine = PciHostIrqs[Idx];

    DEBUG_CODE_BEGIN ();
    {
      CHAR16        *DevPathString;
      STATIC CHAR16 Fallback[] = L"<failed to convert>";
      UINTN         Segment, Bus, Device, Function;

      DevPathString = ConvertDevicePathToText (DevPath, FALSE, FALSE);
      if (DevPathString == NULL) {
        DevPathString = Fallback;
      }
      Status = PciIo->GetLocation (PciIo, &Segment, &Bus, &Device, &Function);
      ASSERT_EFI_ERROR (Status);

      DEBUG ((EFI_D_VERBOSE, "%a: [%02x:%02x.%x] %s -> 0x%02x\n", __FUNCTION__,
        (UINT32)Bus, (UINT32)Device, (UINT32)Function, DevPathString,
        IrqLine));

      if (DevPathString != Fallback) {
        FreePool (DevPathString);
      }
    }
    DEBUG_CODE_END ();

    //
    // Set PCI Interrupt Line register for this device to PciHostIrqs[Idx]
    //
    Status = PciIo->Pci.Write (
               PciIo,
               EfiPciIoWidthUint8,
               PCI_INT_LINE_OFFSET,
               1,
               &IrqLine
               );
  }

  return Status;
}


VOID
PciAcpiInitialization (
  )
{
  UINTN  Pmba;

  //
  // Query Host Bridge DID to determine platform type
  //
  mHostBridgeDevId = PcdGet16 (PcdOvmfHostBridgePciDevId);
  switch (mHostBridgeDevId) {
    case INTEL_82441_DEVICE_ID:
      Pmba = POWER_MGMT_REGISTER_PIIX4 (PIIX4_PMBA);
      //
      // 00:01.0 ISA Bridge (PIIX4) LNK routing targets
      //
      PciWrite8 (PCI_LIB_ADDRESS (0, 1, 0, 0x60), 0x0b); // A
      PciWrite8 (PCI_LIB_ADDRESS (0, 1, 0, 0x61), 0x0b); // B
      PciWrite8 (PCI_LIB_ADDRESS (0, 1, 0, 0x62), 0x0a); // C
      PciWrite8 (PCI_LIB_ADDRESS (0, 1, 0, 0x63), 0x0a); // D
      break;
    case INTEL_Q35_MCH_DEVICE_ID:
      Pmba = POWER_MGMT_REGISTER_Q35 (ICH9_PMBASE);
      //
      // 00:1f.0 LPC Bridge (Q35) LNK routing targets
      //
      PciWrite8 (PCI_LIB_ADDRESS (0, 0x1f, 0, 0x60), 0x0a); // A
      PciWrite8 (PCI_LIB_ADDRESS (0, 0x1f, 0, 0x61), 0x0a); // B
      PciWrite8 (PCI_LIB_ADDRESS (0, 0x1f, 0, 0x62), 0x0b); // C
      PciWrite8 (PCI_LIB_ADDRESS (0, 0x1f, 0, 0x63), 0x0b); // D
      PciWrite8 (PCI_LIB_ADDRESS (0, 0x1f, 0, 0x68), 0x0a); // E
      PciWrite8 (PCI_LIB_ADDRESS (0, 0x1f, 0, 0x69), 0x0a); // F
      PciWrite8 (PCI_LIB_ADDRESS (0, 0x1f, 0, 0x6a), 0x0b); // G
      PciWrite8 (PCI_LIB_ADDRESS (0, 0x1f, 0, 0x6b), 0x0b); // H
      break;
    default:
      DEBUG ((EFI_D_ERROR, "%a: Unknown Host Bridge Device ID: 0x%04x\n",
        __FUNCTION__, mHostBridgeDevId));
      ASSERT (FALSE);
      return;
  }

  //
  // Initialize PCI_INTERRUPT_LINE for applicable present PCI devices
  //
  VisitAllPciInstances (SetPciIntLine);

  //
  // Set ACPI SCI_EN bit in PMCNTRL
  //
  IoOr16 ((PciRead32 (Pmba) & ~BIT0) + 4, BIT0);
}

/**
  This function detects if OVMF is running on Xen.

**/
STATIC
BOOLEAN
XenDetected (
  VOID
  )
{
  EFI_HOB_GUID_TYPE         *GuidHob;
  STATIC INTN               FoundHob = -1;

  if (FoundHob == 0) {
    return FALSE;
  } else if (FoundHob == 1) {
    return TRUE;
  }

  //
  // See if a XenInfo HOB is available
  //
  GuidHob = GetFirstGuidHob (&gEfiXenInfoGuid);
  if (GuidHob == NULL) {
    FoundHob = 0;
    return FALSE;
  }

  FoundHob = 1;
  return TRUE;
}

EFI_STATUS
EFIAPI
ConnectRecursivelyIfPciMassStorage (
  IN EFI_HANDLE           Handle,
  IN EFI_PCI_IO_PROTOCOL  *Instance,
  IN PCI_TYPE00           *PciHeader
  )
{
  EFI_STATUS                Status;
  EFI_DEVICE_PATH_PROTOCOL  *DevicePath;
  CHAR16                    *DevPathStr;

  //
  // Recognize PCI Mass Storage, and Xen PCI devices
  //
  if (IS_CLASS1 (PciHeader, PCI_CLASS_MASS_STORAGE) ||
      (XenDetected() && IS_CLASS2 (PciHeader, 0xFF, 0x80))) {
    DevicePath = NULL;
    Status = gBS->HandleProtocol (
                    Handle,
                    &gEfiDevicePathProtocolGuid,
                    (VOID*)&DevicePath
                    );
    if (EFI_ERROR (Status)) {
      return Status;
    }

    //
    // Print Device Path
    //
    DevPathStr = ConvertDevicePathToText (DevicePath, FALSE, FALSE);
    if (DevPathStr != NULL) {
      DEBUG((
        EFI_D_INFO,
        "Found %s device: %s\n",
        (IS_CLASS1 (PciHeader, PCI_CLASS_MASS_STORAGE) ?
         L"Mass Storage" :
         L"Xen"
         ),
        DevPathStr
        ));
      FreePool(DevPathStr);
    }

    Status = gBS->ConnectController (Handle, NULL, NULL, TRUE);
    if (EFI_ERROR (Status)) {
      return Status;
    }

  }

  return EFI_SUCCESS;
}


/**
  This notification function is invoked when the
  EMU Variable FVB has been changed.

  @param  Event                 The event that occurred
  @param  Context               For EFI compatibility.  Not used.

**/
VOID
EFIAPI
EmuVariablesUpdatedCallback (
  IN  EFI_EVENT Event,
  IN  VOID      *Context
  )
{
  DEBUG ((EFI_D_INFO, "EmuVariablesUpdatedCallback\n"));
  UpdateNvVarsOnFileSystem ();
}


EFI_STATUS
EFIAPI
VisitingFileSystemInstance (
  IN EFI_HANDLE  Handle,
  IN VOID        *Instance,
  IN VOID        *Context
  )
{
  EFI_STATUS      Status;
  STATIC BOOLEAN  ConnectedToFileSystem = FALSE;
  RETURN_STATUS   PcdStatus;

  if (ConnectedToFileSystem) {
    return EFI_ALREADY_STARTED;
  }

  Status = ConnectNvVarsToFileSystem (Handle);
  if (EFI_ERROR (Status)) {
    return Status;
  }

  ConnectedToFileSystem = TRUE;
  mEmuVariableEvent =
    EfiCreateProtocolNotifyEvent (
      &gEfiDevicePathProtocolGuid,
      TPL_CALLBACK,
      EmuVariablesUpdatedCallback,
      NULL,
      &mEmuVariableEventReg
      );
  PcdStatus = PcdSet64S (PcdEmuVariableEvent,
                (UINT64)(UINTN) mEmuVariableEvent);
  ASSERT_RETURN_ERROR (PcdStatus);

  return EFI_SUCCESS;
}


VOID
PlatformBdsRestoreNvVarsFromHardDisk (
  )
{
  VisitAllPciInstances (ConnectRecursivelyIfPciMassStorage);
  VisitAllInstancesOfProtocol (
    &gEfiSimpleFileSystemProtocolGuid,
    VisitingFileSystemInstance,
    NULL
    );

}

/**
  Connect with predefined platform connect sequence.

  The OEM/IBV can customize with their own connect sequence.
**/
VOID
PlatformBdsConnectSequence (
  VOID
  )
{
  UINTN         Index;
  RETURN_STATUS Status;

  DEBUG ((EFI_D_INFO, "PlatformBdsConnectSequence\n"));

  Index = 0;

  //
  // Here we can get the customized platform connect sequence
  // Notes: we can connect with new variable which record the
  // last time boots connect device path sequence
  //
  while (gPlatformConnectSequence[Index] != NULL) {
    //
    // Build the platform boot option
    //
    EfiBootManagerConnectDevicePath (gPlatformConnectSequence[Index], NULL);
    Index++;
  }

  Status = ConnectDevicesFromQemu ();
  if (RETURN_ERROR (Status)) {
    //
    // Just use the simple policy to connect all devices
    //
    DEBUG ((DEBUG_INFO, "EfiBootManagerConnectAll\n"));
    EfiBootManagerConnectAll ();
  }
}

/**
  Save the S3 boot script.

  Note that DxeSmmReadyToLock must be signaled after this function returns;
  otherwise the script wouldn't be saved actually.
**/
STATIC
VOID
SaveS3BootScript (
  VOID
  )
{
  EFI_STATUS                 Status;
  EFI_S3_SAVE_STATE_PROTOCOL *BootScript;
  STATIC CONST UINT8         Info[] = { 0xDE, 0xAD, 0xBE, 0xEF };

  Status = gBS->LocateProtocol (&gEfiS3SaveStateProtocolGuid, NULL,
                  (VOID **) &BootScript);
  ASSERT_EFI_ERROR (Status);

  //
  // Despite the opcode documentation in the PI spec, the protocol
  // implementation embeds a deep copy of the info in the boot script, rather
  // than storing just a pointer to runtime or NVS storage.
  //
  Status = BootScript->Write(BootScript, EFI_BOOT_SCRIPT_INFORMATION_OPCODE,
                         (UINT32) sizeof Info,
                         (EFI_PHYSICAL_ADDRESS)(UINTN) &Info);
  ASSERT_EFI_ERROR (Status);
}


/**
  Do the platform specific action after the console is ready

  Possible things that can be done in PlatformBootManagerAfterConsole:

  > Console post action:
    > Dynamically switch output mode from 100x31 to 80x25 for certain senarino
    > Signal console ready platform customized event
  > Run diagnostics like memory testing
  > Connect certain devices
  > Dispatch aditional option roms
  > Special boot: e.g.: USB boot, enter UI
**/
VOID
EFIAPI
PlatformBootManagerAfterConsole (
  VOID
  )
{
  EFI_BOOT_MODE                      BootMode;

  DEBUG ((EFI_D_INFO, "PlatformBootManagerAfterConsole\n"));

  if (PcdGetBool (PcdOvmfFlashVariablesEnable)) {
    DEBUG ((EFI_D_INFO, "PlatformBdsPolicyBehavior: not restoring NvVars "
      "from disk since flash variables appear to be supported.\n"));
  } else {
    //
    // Try to restore variables from the hard disk early so
    // they can be used for the other BDS connect operations.
    //
    PlatformBdsRestoreNvVarsFromHardDisk ();
  }

  //
  // Get current Boot Mode
  //
  BootMode = GetBootModeHob ();
  DEBUG ((DEBUG_INFO, "Boot Mode:%x\n", BootMode));

  //
  // Go the different platform policy with different boot mode
  // Notes: this part code can be change with the table policy
  //
  ASSERT (BootMode == BOOT_WITH_FULL_CONFIGURATION);

  //
  // Logo show
  //
  BootLogoEnableLogo ();

  //
  // Set PCI Interrupt Line registers and ACPI SCI_EN
  //
  PciAcpiInitialization ();

  //
  // Process TPM PPI request
  //
  Tcg2PhysicalPresenceLibProcessRequest (NULL);

  //
  // Process QEMU's -kernel command line option
  //
  TryRunningQemuKernel ();

  //
  // Perform some platform specific connect sequence
  //
  PlatformBdsConnectSequence ();

  EfiBootManagerRefreshAllBootOption ();

  //
  // Register UEFI Shell
  //
  PlatformRegisterFvBootOption (
    PcdGetPtr (PcdShellFile), L"EFI Internal Shell", LOAD_OPTION_ACTIVE
    );

  RemoveStaleFvFileOptions ();
  SetBootOrderFromQemu ();

  PlatformBmPrintScRegisterHandler ();
}

/**
  This notification function is invoked when an instance of the
  EFI_DEVICE_PATH_PROTOCOL is produced.

  @param  Event                 The event that occurred
  @param  Context               For EFI compatibility.  Not used.

**/
VOID
EFIAPI
NotifyDevPath (
  IN  EFI_EVENT Event,
  IN  VOID      *Context
  )
{
  EFI_HANDLE                            Handle;
  EFI_STATUS                            Status;
  UINTN                                 BufferSize;
  EFI_DEVICE_PATH_PROTOCOL             *DevPathNode;
  ATAPI_DEVICE_PATH                    *Atapi;

  //
  // Examine all new handles
  //
  for (;;) {
    //
    // Get the next handle
    //
    BufferSize = sizeof (Handle);
    Status = gBS->LocateHandle (
              ByRegisterNotify,
              NULL,
              mEfiDevPathNotifyReg,
              &BufferSize,
              &Handle
              );

    //
    // If not found, we're done
    //
    if (EFI_NOT_FOUND == Status) {
      break;
    }

    if (EFI_ERROR (Status)) {
      continue;
    }

    //
    // Get the DevicePath protocol on that handle
    //
    Status = gBS->HandleProtocol (Handle, &gEfiDevicePathProtocolGuid,
                    (VOID **)&DevPathNode);
    ASSERT_EFI_ERROR (Status);

    while (!IsDevicePathEnd (DevPathNode)) {
      //
      // Find the handler to dump this device path node
      //
      if (
           (DevicePathType(DevPathNode) == MESSAGING_DEVICE_PATH) &&
           (DevicePathSubType(DevPathNode) == MSG_ATAPI_DP)
         ) {
        Atapi = (ATAPI_DEVICE_PATH*) DevPathNode;
        PciOr16 (
          PCI_LIB_ADDRESS (
            0,
            1,
            1,
            (Atapi->PrimarySecondary == 1) ? 0x42: 0x40
            ),
          BIT15
          );
      }

      //
      // Next device path node
      //
      DevPathNode = NextDevicePathNode (DevPathNode);
    }
  }

  return;
}


VOID
InstallDevicePathCallback (
  VOID
  )
{
  DEBUG ((EFI_D_INFO, "Registered NotifyDevPath Event\n"));
  mEfiDevPathEvent = EfiCreateProtocolNotifyEvent (
                          &gEfiDevicePathProtocolGuid,
                          TPL_CALLBACK,
                          NotifyDevPath,
                          NULL,
                          &mEfiDevPathNotifyReg
                          );
}

/**
  This function is called each second during the boot manager waits the
  timeout.

  @param TimeoutRemain  The remaining timeout.
**/
VOID
EFIAPI
PlatformBootManagerWaitCallback (
  UINT16          TimeoutRemain
  )
{
  EFI_GRAPHICS_OUTPUT_BLT_PIXEL_UNION Black;
  EFI_GRAPHICS_OUTPUT_BLT_PIXEL_UNION White;
  UINT16                              Timeout;

  Timeout = PcdGet16 (PcdPlatformBootTimeOut);

  Black.Raw = 0x00000000;
  White.Raw = 0x00FFFFFF;

  BootLogoUpdateProgress (
    White.Pixel,
    Black.Pixel,
    L"Start boot option",
    White.Pixel,
    (Timeout - TimeoutRemain) * 100 / Timeout,
    0
    );
}

/**
  The function is called when no boot option could be launched,
  including platform recovery options and options pointing to applications
  built into firmware volumes.

  If this function returns, BDS attempts to enter an infinite loop.
**/
VOID
EFIAPI
PlatformBootManagerUnableToBoot (
  VOID
  )
{
  EFI_STATUS                   Status;
  EFI_INPUT_KEY                Key;
  EFI_BOOT_MANAGER_LOAD_OPTION BootManagerMenu;
  UINTN                        Index;

  //
  // BootManagerMenu doesn't contain the correct information when return status
  // is EFI_NOT_FOUND.
  //
  Status = EfiBootManagerGetBootManagerMenu (&BootManagerMenu);
  if (EFI_ERROR (Status)) {
    return;
  }
  //
  // Normally BdsDxe does not print anything to the system console, but this is
  // a last resort -- the end-user will likely not see any DEBUG messages
  // logged in this situation.
  //
  // AsciiPrint() will NULL-check gST->ConOut internally. We check gST->ConIn
  // here to see if it makes sense to request and wait for a keypress.
  //
  if (gST->ConIn != NULL) {
    AsciiPrint (
      "%a: No bootable option or device was found.\n"
      "%a: Press any key to enter the Boot Manager Menu.\n",
      gEfiCallerBaseName,
      gEfiCallerBaseName
      );
    Status = gBS->WaitForEvent (1, &gST->ConIn->WaitForKey, &Index);
    ASSERT_EFI_ERROR (Status);
    ASSERT (Index == 0);

    //
    // Drain any queued keys.
    //
    while (!EFI_ERROR (gST->ConIn->ReadKeyStroke (gST->ConIn, &Key))) {
      //
      // just throw away Key
      //
    }
  }

  for (;;) {
    EfiBootManagerBoot (&BootManagerMenu);
  }
}