text: /** @file
    ConsoleOut Routines that speak VGA? using Csm module 
  
  Copyright (c) 2007 - 2012, 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.
  //Slice - reworked 2011
  **/
  
  #include "BiosVideo.h"
  //#include <Protocol/MsgLog.h>
  #include <Library/PrintLib.h>
  #include <Library/MemLogLib.h>
  
  
  #ifndef DEBUG_ALL
  #define DEBUG_CSM 1
  #else
  #define DEBUG_CSM DEBUG_ALL
  #endif
  
  #if DEBUG_CSM==0
  #define DBG(...)
  #elif DEBUG_CSM == 1
  //#define DBG(...) BootLog(__VA_ARGS__)
  #define DBG(...) MemLog(TRUE, 1, __VA_ARGS__)
  #elif DEBUG_CSM == 2
  #define DBG(...) AsciiPrint(__VA_ARGS__);
  #else
  #define DBG(...) MemLog(TRUE, 0, __VA_ARGS__)
  #endif
  
  //#include "Version.h"
  //CONST CHAR16* CloverRevision = FIRMWARE_REVISION;
  //CONST CHAR8* CloverRevision = REVISION_STR;
  
  BOOLEAN gBiosVideoBlockSwitchMode = FALSE;
  
  
  //
  // EFI Driver Binding Protocol Instance
  //
  EFI_DRIVER_BINDING_PROTOCOL gBiosVideoDriverBinding = {
    BiosVideoDriverBindingSupported,
    BiosVideoDriverBindingStart,
    BiosVideoDriverBindingStop,
    0x10,
    NULL,
    NULL
  };
  
  //
  // Global lookup tables for VGA graphics modes
  //
  UINT8                          mVgaLeftMaskTable[]   = { 0xff, 0x7f, 0x3f, 0x1f, 0x0f, 0x07, 0x03, 0x01 };
  
  UINT8                          mVgaRightMaskTable[]  = { 0x80, 0xc0, 0xe0, 0xf0, 0xf8, 0xfc, 0xfe, 0xff };
  
  UINT8                          mVgaBitMaskTable[]    = { 0x80, 0x40, 0x20, 0x10, 0x08, 0x04, 0x02, 0x01 };
  
  //
  // Save controller attributes during first start
  //
  UINT64                         mOriginalPciAttributes;
  BOOLEAN                        mPciAttributesSaved = FALSE;
  
  EFI_GRAPHICS_OUTPUT_BLT_PIXEL  mVgaColorToGraphicsOutputColor[] = {
    //
    // {B, G, R, Alpha}
    //  
    {0x00, 0x00, 0x00, 0x00}, // BLACK
    {0x98, 0x00, 0x00, 0x00}, // LIGHTBLUE
    {0x00, 0x98, 0x00, 0x00}, // LIGHGREEN
    {0x98, 0x98, 0x00, 0x00}, // LIGHCYAN
    {0x00, 0x00, 0x98, 0x00}, // LIGHRED
    {0x98, 0x00, 0x98, 0x00}, // MAGENTA
    {0x00, 0x98, 0x98, 0x00}, // BROWN
    {0x98, 0x98, 0x98, 0x00}, // LIGHTGRAY
    {0x10, 0x10, 0x10, 0x00},
    {0xff, 0x10, 0x10, 0x00}, // BLUE
    {0x10, 0xff, 0x10, 0x00}, // LIME
    {0xff, 0xff, 0x10, 0x00}, // CYAN
    {0x10, 0x10, 0xff, 0x00}, // RED
    {0xf0, 0x10, 0xff, 0x00}, // FUCHSIA
    {0x10, 0xff, 0xff, 0x00}, // YELLOW
    {0xff, 0xff, 0xff, 0x00}  // WHITE  
  };
  
  //
  // Standard timing defined by VESA EDID
  //
  VESA_BIOS_EXTENSIONS_EDID_TIMING mEstablishedEdidTiming[] = {
    //
    // Established Timing I
    //
    {800, 600, 60},
    {800, 600, 56},
    {640, 480, 75},
    {640, 480, 72},
    {640, 480, 67},
    {640, 480, 60},
    {720, 400, 88},
    {720, 400, 70},
    //
    // Established Timing II
    //
    {1280, 1024, 75},
    {1024,  768, 75},
    {1024,  768, 70},
    {1024,  768, 60},
    {1024,  768, 87},
    {832,   624, 75},
    {800,   600, 75},
    {800,   600, 72},
    //
    // Established Timing III
    //
    {1152, 870, 75}
  };
  
  /**
    Supported.
  
    @param  This                   Pointer to driver binding protocol
    @param  Controller             Controller handle to connect
    @param  RemainingDevicePath    A pointer to the remaining portion of a device
                                   path
  
    @retval EFI_STATUS             EFI_SUCCESS:This controller can be managed by this
                                   driver, Otherwise, this controller cannot be
                                   managed by this driver
  
  **/
  EFI_STATUS
  EFIAPI
  BiosVideoDriverBindingSupported (
    IN EFI_DRIVER_BINDING_PROTOCOL  *This,
    IN EFI_HANDLE                   Controller,
    IN EFI_DEVICE_PATH_PROTOCOL     *RemainingDevicePath
    )
  {
    EFI_STATUS                Status;
    EFI_LEGACY_BIOS_PROTOCOL  *LegacyBios;
    EFI_PCI_IO_PROTOCOL       *PciIo;
    PCI_TYPE00                Pci;
    EFI_DEV_PATH              *Node;
  
    //
    // See if the Legacy BIOS Protocol is available
    //
    Status = gBS->LocateProtocol (&gEfiLegacyBiosProtocolGuid, NULL, (VOID **) &LegacyBios);
    if (EFI_ERROR (Status)) {
  //    DBG("LegacyBios not found\n");
      return Status;
    }
  
    //
    // Open the IO Abstraction(s) needed to perform the supported test
    //
    Status = gBS->OpenProtocol (
                    Controller,
                    &gEfiPciIoProtocolGuid,
                    (VOID **) &PciIo,
                    This->DriverBindingHandle,
                    Controller,
                    EFI_OPEN_PROTOCOL_BY_DRIVER
                    );
    if (EFI_ERROR (Status) /* && (Status != EFI_ALREADY_STARTED) */) {
  //    DBG("PciIo not found\n");
      return Status;
    }
  
    if (Status == EFI_ALREADY_STARTED) {
      DBG("EFI_ALREADY_STARTED\n");
      //
      // If VgaMiniPort protocol is installed, EFI_ALREADY_STARTED indicates failure,
      // because VgaMiniPort protocol is installed on controller handle directly.
      //
      Status = gBS->OpenProtocol (
                      Controller,
                      &gEfiVgaMiniPortProtocolGuid,
                      NULL,
                      NULL,
                      NULL,
                      EFI_OPEN_PROTOCOL_TEST_PROTOCOL
                      );
      if (!EFI_ERROR (Status)) {
        return EFI_ALREADY_STARTED;
      }
    }
    //
    // See if this is a PCI Graphics Controller by looking at the Command register and
    // Class Code Register
    //
    Status = PciIo->Pci.Read (
                          PciIo,
                          EfiPciIoWidthUint32,
                          0,
                          sizeof (Pci) / sizeof (UINT32),
                          &Pci
                          );
    if (EFI_ERROR (Status)) {
      DBG("PciIo->Pci.Read status=%r\n", Status);
      Status = EFI_UNSUPPORTED;
      goto Done;
    }
  
    Status = EFI_UNSUPPORTED;
    if ((Pci.Hdr.ClassCode[2] == 0x03 || (Pci.Hdr.ClassCode[2] == 0x00 && Pci.Hdr.ClassCode[1] == 0x01)) &&
         Pci.Hdr.VendorId != 0x8086) {
  
      Status = EFI_SUCCESS;
      //
      // If this is a graphics controller,
      // go further check RemainingDevicePath validation
      //
      if (RemainingDevicePath != NULL) {
        Node = (EFI_DEV_PATH *) RemainingDevicePath;
        //
        // Check if RemainingDevicePath is the End of Device Path Node, 
        // if yes, return EFI_SUCCESS
        //
        if (!IsDevicePathEnd (Node)) {
          //
          // If RemainingDevicePath isn't the End of Device Path Node,
          // check its validation
          //
          if (Node->DevPath.Type != ACPI_DEVICE_PATH ||
              Node->DevPath.SubType != ACPI_ADR_DP ||
              DevicePathNodeLength(&Node->DevPath) < sizeof(ACPI_ADR_DEVICE_PATH)) {  
            //Mars Lin suggested that "<" instead of "!="
            Status = EFI_UNSUPPORTED;
            DBG("Mars Lin suggested status=%r\n", Status);
          }
        }
      }
    }
  
  Done:
  //  DBG("Supported status:%r\n", Status);
    gBS->CloseProtocol (
           Controller,
           &gEfiPciIoProtocolGuid,
           This->DriverBindingHandle,
           Controller
           );
  
    return Status;
  }
  
  /**
    Install Graphics Output Protocol onto VGA device handles.
  
    @param  This                   Pointer to driver binding protocol
    @param  Controller             Controller handle to connect
    @param  RemainingDevicePath    A pointer to the remaining portion of a device
                                   path
  
    @return EFI_STATUS
  
  **/
  EFI_STATUS
  EFIAPI
  BiosVideoDriverBindingStart (
    IN EFI_DRIVER_BINDING_PROTOCOL  *This,
    IN EFI_HANDLE                   Controller,
    IN EFI_DEVICE_PATH_PROTOCOL     *RemainingDevicePath
    )
  {
    EFI_STATUS                Status;
    EFI_DEVICE_PATH_PROTOCOL  *ParentDevicePath;
    EFI_PCI_IO_PROTOCOL       *PciIo;
    EFI_LEGACY_BIOS_PROTOCOL  *LegacyBios;
    UINTN                     Flags;
    UINT64                    Supports;
  
    DBG("CsmVideoDriverBindingStart\n");
  
    //
    // Initialize local variables
    //
    PciIo            = NULL;
    ParentDevicePath = NULL;
  
    //
    //
    // See if the Legacy BIOS Protocol is available
    //
    Status = gBS->LocateProtocol (&gEfiLegacyBiosProtocolGuid, NULL, (VOID **) &LegacyBios);
  
    if (EFI_ERROR (Status)) {
       DBG("Legacy BIOS Protocol  status=%r\n", Status); 
       return Status;
    }
  
    //
    // Prepare for status code
    //
    Status = gBS->HandleProtocol (
                    Controller,
                    &gEfiDevicePathProtocolGuid,
                    (VOID **) &ParentDevicePath
                    );
    if (EFI_ERROR (Status)) {
      DBG("ParentDevicePath status=%r\n", Status);
      return Status;
    }
  
    //
    // Open the IO Abstraction(s) needed
    //
    Status = gBS->OpenProtocol (
                    Controller,
                    &gEfiPciIoProtocolGuid,
                    (VOID **) &PciIo,
                    This->DriverBindingHandle,
                    Controller,
                    EFI_OPEN_PROTOCOL_BY_DRIVER
                    );
    if (EFI_ERROR (Status) /* && (Status != EFI_ALREADY_STARTED) */) {
      DBG("OpenProtocol PCI status=%r\n", Status);
      return Status;
    }
  
    //
    // Save original PCI attributes
    //
    if (!mPciAttributesSaved) {
    Status = PciIo->Attributes (
                      PciIo,
                      EfiPciIoAttributeOperationGet,
                      0,
                        &mOriginalPciAttributes
                      );
    if (EFI_ERROR (Status)) {
      DBG("Save original PCI attributes status=%r\n", Status);
      goto Done;
    }
      mPciAttributesSaved = TRUE;
    }
  
    //
    // Get supported PCI attributes
    //
    Status = PciIo->Attributes (
                      PciIo,
                      EfiPciIoAttributeOperationSupported,
                      0,
                      &Supports
                      );
   // Status = EFI_UNSUPPORTED; //temporary - remove it
    if (EFI_ERROR (Status)) {
      DBG("PCI attribute=%x Status=%r\n", Supports, Status);
      goto Done;
    }
    // Check VGA and VGA16, they can not be set at the same time
    Supports &= (EFI_PCI_IO_ATTRIBUTE_VGA_IO | EFI_PCI_IO_ATTRIBUTE_VGA_IO_16);
    if (Supports == 0 || Supports == (EFI_PCI_IO_ATTRIBUTE_VGA_IO | EFI_PCI_IO_ATTRIBUTE_VGA_IO_16)) {
  //    Status = EFI_UNSUPPORTED;
      DBG("mixed support=%x\n", Supports);
      Supports = EFI_PCI_IO_ATTRIBUTE_VGA_IO; //we choose this as in CloverEFI
  //    goto Done;
    }  
  
  /*  REPORT_STATUS_CODE_WITH_DEVICE_PATH (
      EFI_PROGRESS_CODE,
      EFI_PERIPHERAL_LOCAL_CONSOLE | EFI_P_PC_ENABLE,
      ParentDevicePath
      ); */
    //
    // Enable the device and make sure VGA cycles are being forwarded to this VGA device
    //
    Status = PciIo->Attributes (
               PciIo,
               EfiPciIoAttributeOperationEnable,
               EFI_PCI_DEVICE_ENABLE | EFI_PCI_IO_ATTRIBUTE_VGA_MEMORY | Supports,
               NULL
               );
    
    if (EFI_ERROR (Status)) { 
      DBG("Enable the device status=%r\n", Status);
  /*    REPORT_STATUS_CODE_WITH_DEVICE_PATH (
        EFI_ERROR_CODE | EFI_ERROR_MINOR,
        EFI_PERIPHERAL_LOCAL_CONSOLE | EFI_P_EC_RESOURCE_CONFLICT,
        ParentDevicePath
        ); */
      goto Done;
    }
    //
    // Check to see if there is a legacy option ROM image associated with this PCI device
    //
    Status = LegacyBios->CheckPciRom (
                           LegacyBios,
                           Controller,
                           NULL,
                           NULL,
                           &Flags
                           );
    
    if (EFI_ERROR (Status)) {
      DBG("Check PCI ROM status=%r\n", Status);
      goto Done;
    } 
    //
    // Post the legacy option ROM if it is available.
    //
  /*  REPORT_STATUS_CODE_WITH_DEVICE_PATH (
      EFI_PROGRESS_CODE,
      EFI_P_PC_RESET,
      ParentDevicePath
      ); */
    Status = LegacyBios->InstallPciRom (
                           LegacyBios,
                           Controller,
                           NULL,
                           &Flags,
                           NULL,
                           NULL,
                           NULL,
                           NULL
                           );
    
    if (EFI_ERROR (Status)) {
      DBG("InstallPciRom status=%r\n", Status);
  /*      REPORT_STATUS_CODE_WITH_DEVICE_PATH (
        EFI_ERROR_CODE | EFI_ERROR_MINOR,
        EFI_PERIPHERAL_LOCAL_CONSOLE | EFI_P_EC_CONTROLLER_ERROR,
        ParentDevicePath
        ); */
      goto Done;
    }
  
    if (RemainingDevicePath != NULL) {
      if (IsDevicePathEnd (RemainingDevicePath) && 
          (FeaturePcdGet (PcdBiosVideoCheckVbeEnable) || FeaturePcdGet (PcdBiosVideoCheckVgaEnable))) {
        //
        // If RemainingDevicePath is the End of Device Path Node,
        // don't create any child device and return EFI_SUCCESS
        DBG("RemainingDevicePath is the End of Device Path Node\n");
        Status = EFI_SUCCESS;
        goto Done;
      }
    }
  //  Status = EFI_UNSUPPORTED; //temporary - remove it
    if (EFI_ERROR (Status)) {
      goto Done;
    }
  
    //
    // Create child handle and install GraphicsOutputProtocol on it
    //
    Status = BiosVideoChildHandleInstall (
               This,
               Controller,
               PciIo,
               LegacyBios,
               ParentDevicePath,
               RemainingDevicePath
               );
  //  DBG("Child installed\n");
  Done:
  //    Status = EFI_UNSUPPORTED; //temporary - remove it
    if ((EFI_ERROR (Status)) && (Status != EFI_ALREADY_STARTED)) {
  /*    REPORT_STATUS_CODE_WITH_DEVICE_PATH (
        EFI_PROGRESS_CODE,
        EFI_PERIPHERAL_LOCAL_CONSOLE | EFI_P_PC_DISABLE,
        ParentDevicePath
        );
  
      REPORT_STATUS_CODE_WITH_DEVICE_PATH (
        EFI_PROGRESS_CODE,
        EFI_PERIPHERAL_LOCAL_CONSOLE | EFI_P_EC_NOT_DETECTED,
        ParentDevicePath
        ); */
      if (!HasChildHandle (Controller)) {
        if (mPciAttributesSaved) {
        //
        // Restore original PCI attributes
        //
        PciIo->Attributes (
                        PciIo,
                        EfiPciIoAttributeOperationSet,
                          mOriginalPciAttributes,
                        NULL
                        );
          DBG("attributes Restored\n");
        }
      }
      //
      // Release PCI I/O Protocols on the controller handle.
      //
      gBS->CloseProtocol (
             Controller,
             &gEfiPciIoProtocolGuid,
             This->DriverBindingHandle,
             Controller
             );
    }
    
    //
    // Boot speedup: set temporary "BiosVideoBlockSwitchMode" RT var
    // to block mode switching from Console driver.
    // "BiosVideoBlockSwitchMode" must be deleted from Clover
    // to enable mode swithing again
    if (Status == EFI_SUCCESS) {
      gBiosVideoBlockSwitchMode = TRUE;
      gRT->SetVariable(L"BiosVideoBlockSwitchMode", &gEfiGlobalVariableGuid, EFI_VARIABLE_BOOTSERVICE_ACCESS, 1, &Status);
    }
    
    DBG("CsmVideoDriverBindingStart end %r\n", Status);
    return Status;
  }
  
  
  /**
    Stop this driver on Controller 
  
    @param  This                   Pointer to driver binding protocol
    @param  Controller             Controller handle to connect
    @param  NumberOfChildren       Number of children handle created by this driver
    @param  ChildHandleBuffer      Buffer containing child handle created
  
    @retval EFI_SUCCESS            Driver disconnected successfully from controller
    @retval EFI_UNSUPPORTED        Cannot find BIOS_VIDEO_DEV structure
  
  **/
  EFI_STATUS
  EFIAPI
  BiosVideoDriverBindingStop (
    IN  EFI_DRIVER_BINDING_PROTOCOL     *This,
    IN  EFI_HANDLE                      Controller,
    IN  UINTN                           NumberOfChildren,
    IN  EFI_HANDLE                      *ChildHandleBuffer
    )
  {
    EFI_STATUS                   Status;
    BOOLEAN                      AllChildrenStopped;
    UINTN                        Index;
    EFI_PCI_IO_PROTOCOL          *PciIo;
  
    if (NumberOfChildren == 0) {
      //
      // Close PCI I/O protocol on the controller handle
      //
      gBS->CloseProtocol (
             Controller,
             &gEfiPciIoProtocolGuid,
             This->DriverBindingHandle,
             Controller
             );
  
      return EFI_SUCCESS;
    }
  
    AllChildrenStopped = TRUE;
    for (Index = 0; Index < NumberOfChildren; Index++) {
      Status = BiosVideoChildHandleUninstall (This, Controller, ChildHandleBuffer[Index]);
  
      if (EFI_ERROR (Status)) {
        AllChildrenStopped = FALSE;
      }
    }
  
    if (!AllChildrenStopped) {
      return EFI_DEVICE_ERROR;
    }
  
    if (!HasChildHandle (Controller)) {
      if (mPciAttributesSaved) {
        Status = gBS->HandleProtocol (
                        Controller,
                        &gEfiPciIoProtocolGuid,
                        (VOID **) &PciIo
                        );
  //      ASSERT_EFI_ERROR (Status);  //Slice - I hate ASSERT
        if (!EFI_ERROR (Status)){
        //
        // Restore original PCI attributes
        //
        /*Status = */PciIo->Attributes (
                          PciIo,
                          EfiPciIoAttributeOperationSet,
                          mOriginalPciAttributes,
                          NULL
                          );
        }
      }
    }
  
  
    return EFI_SUCCESS;
  }
  
  /**
    Install child hanlde for a detect BiosVideo device and install related protocol
    into this handle, such as EFI_GRAPHIC_OUTPUT_PROTOCOL.
  
    @param  This                   Calling context.
    @param  ParentHandle           Parent Handle
    @param  ParentPciIo            Parent PciIo interface
    @param  ParentLegacyBios       Parent LegacyBios interface
    @param  ParentDevicePath       Parent Device Path
    @param  RemainingDevicePath    Remaining Device Path
  
    @retval EFI_SUCCESS            If a child handle was added
    @retval other                  A child handle was not added
  
  **/
  EFI_STATUS
  BiosVideoChildHandleInstall (
    IN  EFI_DRIVER_BINDING_PROTOCOL  *This,
    IN  EFI_HANDLE                   ParentHandle,
    IN  EFI_PCI_IO_PROTOCOL          *ParentPciIo,
    IN  EFI_LEGACY_BIOS_PROTOCOL     *ParentLegacyBios,
    IN  EFI_DEVICE_PATH_PROTOCOL     *ParentDevicePath,
    IN  EFI_DEVICE_PATH_PROTOCOL     *RemainingDevicePath
    )
  {
    EFI_STATUS               Status;
    BIOS_VIDEO_DEV           *BiosVideoPrivate;
    PCI_TYPE00               Pci;
    ACPI_ADR_DEVICE_PATH     AcpiDeviceNode;
    BOOLEAN                  ProtocolInstalled;
  
    //
    // Allocate the private device structure for video device
    //
    BiosVideoPrivate = (BIOS_VIDEO_DEV *) AllocateZeroPool (sizeof (BIOS_VIDEO_DEV));
    if (NULL == BiosVideoPrivate) {
      Status = EFI_OUT_OF_RESOURCES;
      goto Done;
    }
  
    //
    // See if this is a VGA compatible controller or not
    //
    Status = ParentPciIo->Pci.Read (
                            ParentPciIo,
                            EfiPciIoWidthUint32,
                            0,
                            sizeof (Pci) / sizeof (UINT32),
                            &Pci
                            );
    if (EFI_ERROR (Status)) {
      DBG("ParentPciIo->Pci.Read=%r\n", Status);
      goto Done;
    }
    BiosVideoPrivate->VgaCompatible = FALSE;
    if (Pci.Hdr.ClassCode[2] == 0x00 && Pci.Hdr.ClassCode[1] == 0x01) {
      BiosVideoPrivate->VgaCompatible = TRUE;
    }
  
    if (Pci.Hdr.ClassCode[2] == 0x03 && Pci.Hdr.ClassCode[1] == 0x00 && Pci.Hdr.ClassCode[0] == 0x00) {
      BiosVideoPrivate->VgaCompatible = TRUE;
    }
    DBG("Controller is [%02x%02x%02x]\n", Pci.Hdr.ClassCode[2], Pci.Hdr.ClassCode[1], Pci.Hdr.ClassCode[0]);
   if (0 && PcdGetBool (PcdBiosVideoSetTextVgaModeEnable)) {
      //
      // Create EXIT_BOOT_SERIVES Event
      //
      Status = gBS->CreateEventEx (
                      EVT_NOTIFY_SIGNAL,
                      TPL_NOTIFY,
                      BiosVideoNotifyExitBootServices,
                      BiosVideoPrivate,
                      &gEfiEventExitBootServicesGuid,
                      &BiosVideoPrivate->ExitBootServicesEvent
                      );
      if (EFI_ERROR (Status)) {
        goto Done;
      }
    }
    //
    // Initialize the child private structure
    //
    BiosVideoPrivate->Signature = BIOS_VIDEO_DEV_SIGNATURE;
  
    //
    // Fill in Graphics Output specific mode structures
    //
    BiosVideoPrivate->HardwareNeedsStarting = TRUE;
    BiosVideoPrivate->ModeData              = NULL;
    BiosVideoPrivate->LineBuffer            = NULL;
    BiosVideoPrivate->VgaFrameBuffer        = NULL;
    BiosVideoPrivate->VbeFrameBuffer        = NULL;
  
    //
    // Fill in the Graphics Output Protocol
    //
    BiosVideoPrivate->GraphicsOutput.QueryMode = BiosVideoGraphicsOutputQueryMode;
    BiosVideoPrivate->GraphicsOutput.SetMode   = BiosVideoGraphicsOutputSetMode;
  
  
    //
    // Allocate buffer for Graphics Output Protocol mode information
    //
    BiosVideoPrivate->GraphicsOutput.Mode = (EFI_GRAPHICS_OUTPUT_PROTOCOL_MODE *) AllocatePool (
                                               sizeof (EFI_GRAPHICS_OUTPUT_PROTOCOL_MODE)
                                               );
    if (NULL == BiosVideoPrivate->GraphicsOutput.Mode) {
      Status = EFI_OUT_OF_RESOURCES;
      goto Done;
    }
  
    BiosVideoPrivate->GraphicsOutput.Mode->Info = (EFI_GRAPHICS_OUTPUT_MODE_INFORMATION *) AllocatePool (
                                               sizeof (EFI_GRAPHICS_OUTPUT_MODE_INFORMATION)
                                               );
    if (NULL ==  BiosVideoPrivate->GraphicsOutput.Mode->Info) {
      Status = EFI_OUT_OF_RESOURCES;
      goto Done;
    }
  
    //
    // Assume that Graphics Output Protocol will be produced until proven otherwise
    //
    BiosVideoPrivate->ProduceGraphicsOutput = TRUE;
  
    //
    // Set Gop Device Path, here RemainingDevicePath will not be one End of Device Path Node.
    //
    if ((RemainingDevicePath == NULL) || (!IsDevicePathEnd (RemainingDevicePath))) {
      if (RemainingDevicePath == NULL) {
  //      DBG("null RemainingDevicePath\n");
        gBS->SetMem (&AcpiDeviceNode, sizeof (ACPI_ADR_DEVICE_PATH), 0);
        AcpiDeviceNode.Header.Type = ACPI_DEVICE_PATH;
        AcpiDeviceNode.Header.SubType = ACPI_ADR_DP;
        AcpiDeviceNode.ADR = ACPI_DISPLAY_ADR (1, 0, 0, 1, 0, ACPI_ADR_DISPLAY_TYPE_VGA, 0, 0);
        SetDevicePathNodeLength (&AcpiDeviceNode.Header, sizeof (ACPI_ADR_DEVICE_PATH));
      
        BiosVideoPrivate->GopDevicePath = AppendDevicePathNode (
                                            ParentDevicePath,
                                            (EFI_DEVICE_PATH_PROTOCOL *) &AcpiDeviceNode
                                            );
  //      DBG("GopDevicePath =%a\n", DevicePathToStr(BiosVideoPrivate->GopDevicePath));
  //      DBG("GopDevicePath OK\n");
   //     Status = EFI_UNSUPPORTED;
  /*
        if (EFI_ERROR (Status)) {
          goto Done;
        } */
        
      } else {
        BiosVideoPrivate->GopDevicePath = AppendDevicePathNode (ParentDevicePath, RemainingDevicePath);
        DBG("GopDevicePath\n");
      }    
      
      //
      // Creat child handle and device path protocol firstly
      //
      if (!BiosVideoPrivate->GopDevicePath) {
        DBG("!BiosVideoPrivate->GopDevicePath\n");
        Status = EFI_UNSUPPORTED;
        
        if (EFI_ERROR (Status)) {
          goto Done;
        }
        
      }
      BiosVideoPrivate->Handle = NULL;
      Status = gBS->InstallMultipleProtocolInterfaces (
                      &BiosVideoPrivate->Handle,
                      &gEfiDevicePathProtocolGuid,
                      BiosVideoPrivate->GopDevicePath,
                      NULL
                      );
  //    DBG("Creat child handle %r\n", Status);
   //   Status = EFI_UNSUPPORTED;
  
   /*   if (EFI_ERROR (Status)) {
        goto Done;
      }*/
    }
  
    //
    // Fill in the VGA Mini Port Protocol fields
    //
    BiosVideoPrivate->VgaMiniPort.SetMode                   = BiosVideoVgaMiniPortSetMode;
    BiosVideoPrivate->VgaMiniPort.VgaMemoryOffset           = 0xb8000;
    BiosVideoPrivate->VgaMiniPort.CrtcAddressRegisterOffset = 0x3d4;
    BiosVideoPrivate->VgaMiniPort.CrtcDataRegisterOffset    = 0x3d5;
    BiosVideoPrivate->VgaMiniPort.VgaMemoryBar              = EFI_PCI_IO_PASS_THROUGH_BAR;
    BiosVideoPrivate->VgaMiniPort.CrtcAddressRegisterBar    = EFI_PCI_IO_PASS_THROUGH_BAR;
    BiosVideoPrivate->VgaMiniPort.CrtcDataRegisterBar       = EFI_PCI_IO_PASS_THROUGH_BAR;
  
    //
    // Child handle need to consume the Legacy Bios protocol
    //
    BiosVideoPrivate->LegacyBios = ParentLegacyBios;
  
    //
    // When check for VBE, PCI I/O protocol is needed, so use parent's protocol interface temporally
    //
    BiosVideoPrivate->PciIo                 = ParentPciIo;
  
    //
    // Check for VESA BIOS Extensions for modes that are compatible with Graphics Output
    //
    if (1) { // FeaturePcdGet (PcdBiosVideoCheckVbeEnable)) {
  //   DBG("BiosVideoCheckForVbe start\n");
      Status = BiosVideoCheckForVbe (BiosVideoPrivate);
   //   DEBUG ((EFI_D_INFO, "BiosVideoCheckForVbe - %r\n", Status));
      DBG("CsmVideoCheckForVbe - %r\n", Status);
    } else {
      Status = EFI_UNSUPPORTED;
    }
    if (EFI_ERROR (Status)) {
      //
      // The VESA BIOS Extensions are not compatible with Graphics Output, so check for support
      // for the standard 640x480 16 color VGA mode
      //
   //   DEBUG ((EFI_D_INFO, "VgaCompatible - %x\n", BiosVideoPrivate->VgaCompatible));
      DBG("VgaCompatible - %x\n", BiosVideoPrivate->VgaCompatible);
      if (BiosVideoPrivate->VgaCompatible) {
        if (FeaturePcdGet (PcdBiosVideoCheckVgaEnable)) {
          Status = BiosVideoCheckForVga (BiosVideoPrivate);
   //       DEBUG ((EFI_D_INFO, "BiosVideoCheckForVga - %r\n", Status));
          DBG("CsmVideoCheckForVga - %r\n", Status);
        } else {
          Status = EFI_UNSUPPORTED;
        }
      }
  
      if (EFI_ERROR (Status)) {
        //
        // Free GOP mode structure if it is not freed before
        // VgaMiniPort does not need this structure any more
        //
        if (BiosVideoPrivate->GraphicsOutput.Mode != NULL) {
          if (BiosVideoPrivate->GraphicsOutput.Mode->Info != NULL) {
            FreePool (BiosVideoPrivate->GraphicsOutput.Mode->Info);
            BiosVideoPrivate->GraphicsOutput.Mode->Info = NULL;
          }
          FreePool (BiosVideoPrivate->GraphicsOutput.Mode);
          BiosVideoPrivate->GraphicsOutput.Mode = NULL;
        }
  
        //
        // Neither VBE nor the standard 640x480 16 color VGA mode are supported, so do
        // not produce the Graphics Output protocol.  Instead, produce the VGA MiniPort Protocol.
        //
        BiosVideoPrivate->ProduceGraphicsOutput = FALSE;
  
        //
        // INT services are available, so on the 80x25 and 80x50 text mode are supported
        //
        BiosVideoPrivate->VgaMiniPort.MaxMode = 2;
      }
    }
  
    ProtocolInstalled = FALSE;
  
    if (BiosVideoPrivate->ProduceGraphicsOutput) {
      //
      // Creat child handle and install Graphics Output Protocol,EDID Discovered/Active Protocol
      //
      Status = gBS->InstallMultipleProtocolInterfaces (
                      &BiosVideoPrivate->Handle,
                      &gEfiGraphicsOutputProtocolGuid,
                      &BiosVideoPrivate->GraphicsOutput,
                      &gEfiEdidDiscoveredProtocolGuid,
                      &BiosVideoPrivate->EdidDiscovered,
                      &gEfiEdidActiveProtocolGuid,
                      &BiosVideoPrivate->EdidActive,
                      NULL
                      );
  
      if (!EFI_ERROR (Status)) {
        //
        // Open the Parent Handle for the child
        //
        Status = gBS->OpenProtocol (
                        ParentHandle,
                        &gEfiPciIoProtocolGuid,
                        (VOID **) &BiosVideoPrivate->PciIo,
                        This->DriverBindingHandle,
                        BiosVideoPrivate->Handle,
                        EFI_OPEN_PROTOCOL_BY_CHILD_CONTROLLER
                        );
        if (EFI_ERROR (Status)) {
          goto Done;
        }
        ProtocolInstalled = TRUE;
      }
    }
  
    if (!ProtocolInstalled) {
      //
      // Install VGA Mini Port Protocol
      //
      DBG("Install VGA Mini Port\n");
      Status = gBS->InstallMultipleProtocolInterfaces (
                      &ParentHandle,
                      &gEfiVgaMiniPortProtocolGuid,
                      &BiosVideoPrivate->VgaMiniPort,
                      NULL
                      );
    }
  
  Done:
    if (EFI_ERROR (Status)) {
      if ((BiosVideoPrivate != NULL) && (BiosVideoPrivate->ExitBootServicesEvent != NULL)) {
        gBS->CloseEvent (BiosVideoPrivate->ExitBootServicesEvent);
      }  
      //
      // Free private data structure
      //
      BiosVideoDeviceReleaseResource (BiosVideoPrivate);
    }
  
    return Status;
  }
  
  /**
    Deregister an video child handle and free resources.
  
    @param  This                   Protocol instance pointer.
    @param  Controller             Video controller handle
    @param  Handle                 Video child handle
  
    @return EFI_STATUS
  
  **/
  EFI_STATUS
  BiosVideoChildHandleUninstall (
    EFI_DRIVER_BINDING_PROTOCOL    *This,
    EFI_HANDLE                     Controller,
    EFI_HANDLE                     Handle
    )
  {
    EFI_STATUS                   Status;
    EFI_IA32_REGISTER_SET        Regs;
    EFI_GRAPHICS_OUTPUT_PROTOCOL *GraphicsOutput;
    EFI_VGA_MINI_PORT_PROTOCOL   *VgaMiniPort;
    BIOS_VIDEO_DEV               *BiosVideoPrivate;
    EFI_PCI_IO_PROTOCOL          *PciIo;
  
    BiosVideoPrivate = NULL;
    GraphicsOutput   = NULL;
    PciIo            = NULL;
  //  Status           = EFI_UNSUPPORTED;
  
    Status = gBS->OpenProtocol (
                    Handle,
                    &gEfiGraphicsOutputProtocolGuid,
                    (VOID **) &GraphicsOutput,
                    This->DriverBindingHandle,
                    Handle,
                    EFI_OPEN_PROTOCOL_GET_PROTOCOL
                    );
    if (!EFI_ERROR (Status)) {
        BiosVideoPrivate = BIOS_VIDEO_DEV_FROM_GRAPHICS_OUTPUT_THIS (GraphicsOutput);
    }
  
    if (EFI_ERROR (Status)) {
      Status = gBS->OpenProtocol (
                     Handle,
                     &gEfiVgaMiniPortProtocolGuid,
                     (VOID **) &VgaMiniPort,
                     This->DriverBindingHandle,
                     Handle,
                     EFI_OPEN_PROTOCOL_GET_PROTOCOL
                     );
      if (!EFI_ERROR (Status)) {
        BiosVideoPrivate = BIOS_VIDEO_DEV_FROM_VGA_MINI_PORT_THIS (VgaMiniPort);
      }
    }
  
    if (BiosVideoPrivate == NULL) {
      return EFI_UNSUPPORTED;
    }
  
    //
    // Set the 80x25 Text VGA Mode
    //
    Regs.H.AH = 0x00;
    Regs.H.AL = 0x03;
    BiosVideoPrivate->LegacyBios->Int86 (BiosVideoPrivate->LegacyBios, 0x10, &Regs);
  
    Regs.H.AH = 0x11;
    Regs.H.AL = 0x14;
    Regs.H.BL = 0;
    BiosVideoPrivate->LegacyBios->Int86 (BiosVideoPrivate->LegacyBios, 0x10, &Regs);
  
    //
    // Close PCI I/O protocol that opened by child handle
    //
    Status = gBS->CloseProtocol (
                    Controller,
                    &gEfiPciIoProtocolGuid,
                    This->DriverBindingHandle,
                    Handle
                    );
  
    //
    // Uninstall protocols on child handle
    //
    if (BiosVideoPrivate->ProduceGraphicsOutput) {
      Status = gBS->UninstallMultipleProtocolInterfaces (
                      BiosVideoPrivate->Handle,
                      &gEfiDevicePathProtocolGuid,
                      BiosVideoPrivate->GopDevicePath,
                      &gEfiGraphicsOutputProtocolGuid,
                      &BiosVideoPrivate->GraphicsOutput,
                      &gEfiEdidDiscoveredProtocolGuid,
                      &BiosVideoPrivate->EdidDiscovered,
                      &gEfiEdidActiveProtocolGuid,
                      &BiosVideoPrivate->EdidActive,
                      NULL
                      );
    }
    if (!BiosVideoPrivate->ProduceGraphicsOutput) {
      Status = gBS->UninstallMultipleProtocolInterfaces (
                      Controller,
                      &gEfiVgaMiniPortProtocolGuid,
                      &BiosVideoPrivate->VgaMiniPort,
                      NULL
                      );
    }
  
    if (EFI_ERROR (Status)) {
      gBS->OpenProtocol (
             Controller,
             &gEfiPciIoProtocolGuid,
             (VOID **) &PciIo,
             This->DriverBindingHandle,
             Handle,
             EFI_OPEN_PROTOCOL_BY_CHILD_CONTROLLER
             );
      return Status;
    }
  
  /*  if (PcdGetBool (PcdBiosVideoSetTextVgaModeEnable)) {
      //
      // Close EXIT_BOOT_SERIVES Event
      //
      gBS->CloseEvent (BiosVideoPrivate->ExitBootServicesEvent);
    } */
  
    //
    // Release all allocated resources
    //
    BiosVideoDeviceReleaseResource (BiosVideoPrivate);
  
    return EFI_SUCCESS;
  }
  
  
  /**
    Release resource for biso video instance.
  
    @param  BiosVideoPrivate       Video child device private data structure
  
  **/
  VOID
  BiosVideoDeviceReleaseResource (
    BIOS_VIDEO_DEV  *BiosVideoPrivate
    )
  {
    if (BiosVideoPrivate == NULL) {
      return ;
    }
  
    //
    // Release all the resourses occupied by the BIOS_VIDEO_DEV
    //
  
    //
    // Free VGA Frame Buffer
    //
    if (BiosVideoPrivate->VgaFrameBuffer != NULL) {
      FreePool (BiosVideoPrivate->VgaFrameBuffer);
    }
    //
    // Free VBE Frame Buffer
    //
    if (BiosVideoPrivate->VbeFrameBuffer != NULL) {
      FreePool (BiosVideoPrivate->VbeFrameBuffer);
    }
    //
    // Free line buffer
    //
    if (BiosVideoPrivate->LineBuffer != NULL) {
      FreePool (BiosVideoPrivate->LineBuffer);
    }
    //
    // Free mode data
    //
    if (BiosVideoPrivate->ModeData != NULL) {
      FreePool (BiosVideoPrivate->ModeData);
    }
    //
    // Free memory allocated below 1MB
    //
    if (BiosVideoPrivate->PagesBelow1MB != 0) {
      gBS->FreePages (BiosVideoPrivate->PagesBelow1MB, BiosVideoPrivate->NumberOfPagesBelow1MB);
    }
  
    if (BiosVideoPrivate->VbeSaveRestorePages != 0) {
      gBS->FreePages (BiosVideoPrivate->VbeSaveRestoreBuffer, BiosVideoPrivate->VbeSaveRestorePages);
    }
  
    //
    // Free graphics output protocol occupied resource
    //
    if (BiosVideoPrivate->GraphicsOutput.Mode != NULL) {
      if (BiosVideoPrivate->GraphicsOutput.Mode->Info != NULL) {
          FreePool (BiosVideoPrivate->GraphicsOutput.Mode->Info);
          BiosVideoPrivate->GraphicsOutput.Mode->Info = NULL;
      }
      FreePool (BiosVideoPrivate->GraphicsOutput.Mode);
      BiosVideoPrivate->GraphicsOutput.Mode = NULL;
    }
    //
    // Free EDID discovered protocol occupied resource
    //
    if (BiosVideoPrivate->EdidDiscovered.Edid != NULL) {
      FreePool (BiosVideoPrivate->EdidDiscovered.Edid);
    }
    //
    // Free EDID active protocol occupied resource
    //
    if (BiosVideoPrivate->EdidActive.Edid != NULL) {
      FreePool (BiosVideoPrivate->EdidActive.Edid);
    }
  
    if (BiosVideoPrivate->GopDevicePath!= NULL) {
      FreePool (BiosVideoPrivate->GopDevicePath);
    }
  
    FreePool (BiosVideoPrivate);
  
    return ;
  }
  
  //Subroutines from Joblo's project RadeonFB
  //----------------------------------------------------------------------------------
  
  BOOLEAN edid_checksum(UINT8 *edid)
  {
    INTN i;
    UINT8 csum = 0, all_null = 0;
    
    for (i = 0; i < VESA_BIOS_EXTENSIONS_EDID_BLOCK_SIZE; i++) {
      csum += edid[i];
      all_null |= edid[i];
    }
    
    if (csum == 0x00 && all_null) {
      /* checksum passed, everything's good */
      return TRUE;
    }
    
    return FALSE;
  }
  
  //----------------------------------------------------------------------------------
  const UINT8 edid_v1_header[] = { 0x00, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x00 };
  
  BOOLEAN edid_check_header(UINT8 *edid)
  {
    INTN i; 
    
    for (i = 0; i < 8; i++) {
      if (edid[i] != edid_v1_header[i])
        return FALSE;
    }
    
    return TRUE;
  }
  //------------------------------------------------------------------------
  BOOLEAN verifyEDID(UINT8 *edid)
  {
    if (edid == NULL || !edid_checksum(edid) || !edid_check_header(edid))
    {
      return FALSE;
    }
    return TRUE;
  }
  //----------------------------------------------------------------------------------
  
  /**
    Generate a search key for a specified timing data.
  
  
    @param EdidTiming      - Pointer to EDID timing (w,h,RefreshRate)
  
    @return The 32 bit unique key for search.
  
  **/
  UINT32
  CalculateEdidKey (
    VESA_BIOS_EXTENSIONS_EDID_TIMING       *EdidTiming
    )
  {
    UINT32 Key;
  
    //
    // Be sure no conflicts for all standard timing defined by VESA.
    //
    Key = (EdidTiming->HorizontalResolution * 2) + EdidTiming->VerticalResolution;
    return Key;
  }
  
  /**
    Search a specified Timing in all the valid EDID timings.
  
    @param  ValidEdidTiming        All valid EDID timing information.
    @param  EdidTiming             The Timing to search for.
  
    @retval TRUE                   Found.
    @retval FALSE                  Not found.
  
  **/
  BOOLEAN
  SearchEdidTiming (
    VESA_BIOS_EXTENSIONS_VALID_EDID_TIMING *ValidEdidTiming,
    VESA_BIOS_EXTENSIONS_EDID_TIMING       *EdidTiming
    )
  {
    UINT32 Index;
    UINT32 Key;
  
    Key = CalculateEdidKey (EdidTiming);
  
    for (Index = 0; Index < ValidEdidTiming->ValidNumber; Index ++) {
      if (Key == ValidEdidTiming->Key[Index]) {
        return TRUE;
      }
    }
  
    return FALSE;
  }
  
  
  //
  VOID GetStandardTiming (
    IN  UINT8*                            BufferIndex,
    OUT VESA_BIOS_EXTENSIONS_EDID_TIMING* TempTiming
    )
  //
  // A valid Standard Timing
  //
  {
    UINT16    HorizontalResolution;
    UINT16    VerticalResolution = 0;
    UINT8     RefreshRate;
    UINT8     AspectRatio;
    
    if (!TempTiming) return;
    
    HorizontalResolution = (UINT16) (BufferIndex[0] * 8 + 248);
    AspectRatio = (UINT8) (BufferIndex[1] >> 6);
    switch (AspectRatio) {
      case 0:
        VerticalResolution = (UINT16) (HorizontalResolution / 16 * 10);
        break;
      case 1:
        VerticalResolution = (UINT16) (HorizontalResolution / 4 * 3);
        break;
      case 2:
        VerticalResolution = (UINT16) (HorizontalResolution / 5 * 4);
        break;
      case 3:
        VerticalResolution = (UINT16) (HorizontalResolution / 16 * 9);
        break;
      default:
        VerticalResolution = (UINT16) (HorizontalResolution / 4 * 3);
        break;
    }
    RefreshRate = (UINT8) ((BufferIndex[1] & 0x1f) + 60);
    TempTiming->HorizontalResolution = HorizontalResolution;
    TempTiming->VerticalResolution = VerticalResolution;
    TempTiming->RefreshRate = RefreshRate;
  }
  
  /**
    Parse the Established Timing and Standard Timing in EDID data block.
  
    @param  EdidBuffer             Pointer to EDID data block
    @param  ValidEdidTiming        Valid EDID timing information
  
    @retval TRUE                   The EDID data is valid.
    @retval FALSE                  The EDID data is invalid.
  
  **/
  BOOLEAN
  ParseEdidData (
    UINT8                                      *EdidBuffer,
    VESA_BIOS_EXTENSIONS_VALID_EDID_TIMING     *ValidEdidTiming
    )
  {
    UINT32 Index;
    UINT32 Index2;
    UINT32 ValidNumber;
    UINT32 TimingBits;
    UINT8  *BufferIndex;
    VESA_BIOS_EXTENSIONS_EDID_TIMING     TempTiming;
    VESA_BIOS_EXTENSIONS_EDID_DATA_BLOCK *EdidDataBlock;
    
    EdidDataBlock = (VESA_BIOS_EXTENSIONS_EDID_DATA_BLOCK *) EdidBuffer;
    //
    // Check the checksum of EDID data
    //
    if (!edid_checksum(EdidBuffer)) {
      return FALSE;
    }
    
    ValidNumber = ValidEdidTiming->ValidNumber;
    
    if ((EdidDataBlock->EstablishedTimings[0] != 0) ||
        (EdidDataBlock->EstablishedTimings[1] != 0) ||
        (EdidDataBlock->EstablishedTimings[2] != 0)
        )
    {
      //
      // Established timing data
      //
      TimingBits = EdidDataBlock->EstablishedTimings[0] |
      (EdidDataBlock->EstablishedTimings[1] << 8) |
      ((EdidDataBlock->EstablishedTimings[2] & 0x80) << 9) ;
      for (Index = 0; Index < VESA_BIOS_EXTENSIONS_EDID_ESTABLISHED_TIMING_MAX_NUMBER; Index ++) {
        if ((TimingBits & 0x1)) {
          if (!SearchEdidTiming(ValidEdidTiming, &mEstablishedEdidTiming[Index])){
            ValidEdidTiming->Key[ValidNumber] = CalculateEdidKey (&mEstablishedEdidTiming[Index]);
            ValidNumber ++;
          }
        }
        TimingBits = TimingBits >> 1;
      }
    } // else {
      //
      // If no Established timing data, read the standard timing data
      //
      BufferIndex = &EdidDataBlock->StandardTimingIdentification[0];
      for (Index = 0; Index < 8; Index ++) {
        if ((BufferIndex[0] != 0x1) && (BufferIndex[1] != 0x1)){
          GetStandardTiming(BufferIndex, &TempTiming);
          if (!SearchEdidTiming(ValidEdidTiming, &TempTiming)){
            ValidEdidTiming->Key[ValidNumber] = CalculateEdidKey (&TempTiming);
            ValidNumber ++;
          }
        }
        BufferIndex += 2;
      }
  //  }
    //Slice - DetailedTiming here
    BufferIndex = &EdidDataBlock->DetailedTimingDescriptions[0];
    for (Index = 0; Index < 4; Index ++, BufferIndex += DETAILED_TIMING_DESCRIPTION_SIZE) {
      if ((BufferIndex[0] != 0x00) || (BufferIndex[1] != 0x00) ||
          (BufferIndex[2] != 0x00) || (BufferIndex[4] != 0x00)) {
        TempTiming.HorizontalResolution = ((UINT16)(BufferIndex[4] & 0xF0) << 4) | (BufferIndex[2]);
        TempTiming.VerticalResolution = ((UINT16)(BufferIndex[7] & 0xF0) << 4) | (BufferIndex[5]);
  			DBG(" found Detail Timing %dx%d\n", TempTiming.HorizontalResolution, TempTiming.VerticalResolution);
        TempTiming.RefreshRate = 60; //doesn't matter, it's temporary
        if (!SearchEdidTiming(ValidEdidTiming, &TempTiming)){
          ValidEdidTiming->Key[ValidNumber] = CalculateEdidKey (&TempTiming);
          ValidNumber ++;
  			} else {
  				DBG("... already present\n");
        }
      } else if (BufferIndex[3] == 0xFA) {
        for (Index2 = 0; Index2 < 6; Index2 ++) {
          GetStandardTiming(&BufferIndex[Index2*2 + 5], &TempTiming);
          if (!SearchEdidTiming(ValidEdidTiming, &TempTiming)){
            ValidEdidTiming->Key[ValidNumber] = CalculateEdidKey (&TempTiming);
            ValidNumber ++;
          }
        }
      } else if (BufferIndex[3] == 0xFE) { //Ascii string
        DBG("timing string after 0xFE:%a\n", &BufferIndex[5]);
      }
    }
    
    ValidEdidTiming->ValidNumber = ValidNumber;
    return TRUE;
  }
  
  /**
    Check if all video child handles have been uninstalled.
  
    @param  Controller             Video controller handle
  
    @return TRUE                   Child handles exist.
    @return FALSE                  All video child handles have been uninstalled.
  
  **/
  BOOLEAN
  HasChildHandle (
    IN EFI_HANDLE  Controller
    )
  {
    UINTN                                Index;
    EFI_OPEN_PROTOCOL_INFORMATION_ENTRY  *OpenInfoBuffer;
    UINTN                                EntryCount;
    BOOLEAN                              HasChild;
    EFI_STATUS                           Status;
  
    EntryCount = 0;
    HasChild   = FALSE;
    Status = gBS->OpenProtocolInformation (
                    Controller,
                    &gEfiPciIoProtocolGuid,
                    &OpenInfoBuffer,
                    &EntryCount
                    );
    if (EFI_ERROR(Status)) {
      return FALSE;
    }
    for (Index = 0; Index < EntryCount; Index++) {
      if ((OpenInfoBuffer[Index].Attributes & EFI_OPEN_PROTOCOL_BY_CHILD_CONTROLLER) != 0) {
        HasChild = TRUE;
      }
    }
    
    return HasChild;
  }
  
  /**
    Check for VBE device.
  
    @param  BiosVideoPrivate       Pointer to BIOS_VIDEO_DEV structure
  
    @retval EFI_SUCCESS            VBE device found
  
  **/
  EFI_STATUS
  BiosVideoCheckForVbe (
    IN OUT BIOS_VIDEO_DEV  *BiosVideoPrivate
    )
  {
    EFI_STATUS                             Status;
    EFI_IA32_REGISTER_SET                  Regs;
    UINT16                                 *ModeNumberPtr;
    UINT16                                 VbeModeNumber;
    BOOLEAN                                ModeFound;
    BOOLEAN                                EdidFound;
    BIOS_VIDEO_MODE_DATA                   *ModeBuffer;
    BIOS_VIDEO_MODE_DATA                   *CurrentModeData;
    UINTN                                  PreferMode;
    UINTN                                  ModeNumber;
    VESA_BIOS_EXTENSIONS_EDID_TIMING       Timing;
    VESA_BIOS_EXTENSIONS_VALID_EDID_TIMING ValidEdidTiming;
    EFI_EDID_OVERRIDE_PROTOCOL             *EdidOverride;
    UINT32                                 EdidAttributes;
    BOOLEAN                                EdidOverrideFound;
    UINTN                                  EdidOverrideDataSize;
    UINT8                                  *EdidOverrideDataBlock;
    UINTN                                  EdidActiveDataSize;
    UINT8                                  *EdidActiveDataBlock;
    UINT32                                 HighestHorizontalResolution;
    UINT32                                 HighestVerticalResolution;
    UINTN                                  HighestResolutionMode;
    BOOLEAN                                 ModeConsideredWorking;
  
    EdidFound             = TRUE;
    EdidOverrideFound     = FALSE;
    EdidOverrideDataBlock = NULL;
    EdidActiveDataSize    = 0;
    EdidActiveDataBlock   = NULL;
    HighestHorizontalResolution = 0;
    HighestVerticalResolution   = 0;
    HighestResolutionMode       = 0;
  
    //
    // Allocate buffer under 1MB for VBE data structures
    //
    BiosVideoPrivate->NumberOfPagesBelow1MB = EFI_SIZE_TO_PAGES (
                                                sizeof (VESA_BIOS_EXTENSIONS_INFORMATION_BLOCK) +
                                                sizeof (VESA_BIOS_EXTENSIONS_MODE_INFORMATION_BLOCK) +
                                                sizeof (VESA_BIOS_EXTENSIONS_EDID_DATA_BLOCK) +
                                                sizeof (VESA_BIOS_EXTENSIONS_CRTC_INFORMATION_BLOCK)
                                                );
  
    BiosVideoPrivate->PagesBelow1MB = 0x000C0000 - 1;
  
    Status = gBS->AllocatePages (
                    AllocateMaxAddress,
                    EfiBootServicesData,
                    BiosVideoPrivate->NumberOfPagesBelow1MB,
                    &BiosVideoPrivate->PagesBelow1MB
                    );
    if (EFI_ERROR (Status)) {
      return Status;
    }
  
    gBS->SetMem (&ValidEdidTiming, sizeof (VESA_BIOS_EXTENSIONS_VALID_EDID_TIMING), 0);
    
    //
    // Fill in the VBE related data structures
    //
    BiosVideoPrivate->VbeInformationBlock = (VESA_BIOS_EXTENSIONS_INFORMATION_BLOCK *) (UINTN) (BiosVideoPrivate->PagesBelow1MB);
    BiosVideoPrivate->VbeModeInformationBlock = (VESA_BIOS_EXTENSIONS_MODE_INFORMATION_BLOCK *) (BiosVideoPrivate->VbeInformationBlock + 1);
    BiosVideoPrivate->VbeEdidDataBlock = (VESA_BIOS_EXTENSIONS_EDID_DATA_BLOCK *) (BiosVideoPrivate->VbeModeInformationBlock + 1);
    BiosVideoPrivate->VbeCrtcInformationBlock = (VESA_BIOS_EXTENSIONS_CRTC_INFORMATION_BLOCK *) (BiosVideoPrivate->VbeEdidDataBlock + 1);
    BiosVideoPrivate->VbeSaveRestorePages   = 0;
    BiosVideoPrivate->VbeSaveRestoreBuffer  = 0;
    DBG("Check for VBE\n");
  
    //
    // Test to see if the Video Adapter is compliant with VBE 3.0
    //
    // INT 10 - VESA SuperVGA BIOS (VBE) - GET SuperVGA INFORMATION
    //
    //  AX = 4F00h
    //  ES:DI -> buffer for SuperVGA information (see #00077)
    // Return: AL = 4Fh if function supported
    //  AH = status
    //      00h successful
    //    ES:DI buffer filled
    //      01h failed
    //      ---VBE v2.0---
    //      02h function not supported by current hardware configuration
    //      03h function invalid in current video mode
    // Desc:  determine whether VESA BIOS extensions are present and the capabilities
    //    supported by the display adapter
    //
    gBS->SetMem (&Regs, sizeof (Regs), 0);
    Regs.X.AX = VESA_BIOS_EXTENSIONS_RETURN_CONTROLLER_INFORMATION;
    gBS->SetMem (BiosVideoPrivate->VbeInformationBlock, sizeof (VESA_BIOS_EXTENSIONS_INFORMATION_BLOCK), 0);
    BiosVideoPrivate->VbeInformationBlock->VESASignature  = VESA_BIOS_EXTENSIONS_VBE2_SIGNATURE;
    Regs.X.ES = EFI_SEGMENT ((UINTN) BiosVideoPrivate->VbeInformationBlock);
    Regs.X.DI = EFI_OFFSET ((UINTN) BiosVideoPrivate->VbeInformationBlock);
  
    BiosVideoPrivate->LegacyBios->Int86 (BiosVideoPrivate->LegacyBios, 0x10, &Regs);
  
    Status = EFI_DEVICE_ERROR;
  
    //
    // See if the VESA call succeeded
    //
    if (Regs.X.AX != VESA_BIOS_EXTENSIONS_STATUS_SUCCESS) { //0x004f
      return Status;
    }
    //
    // Check for 'VESA' signature
    //
    if (BiosVideoPrivate->VbeInformationBlock->VESASignature != VESA_BIOS_EXTENSIONS_VESA_SIGNATURE) {
      return Status;
    }
    //
    // Check to see if this is VBE 2.0 or higher
    // No, we will try
    if (BiosVideoPrivate->VbeInformationBlock->VESAVersion < VESA_BIOS_EXTENSIONS_VERSION_2_0) {
  //    return Status;
    }
  
    EdidFound            = FALSE;
    EdidAttributes       = 0xff;
    EdidOverrideDataSize = 0;
  
    //
    // Find EDID Override protocol firstly, this protocol is installed by platform if needed.
    //
    Status = gBS->LocateProtocol (
                     &gEfiEdidOverrideProtocolGuid,
                     NULL,
                     (VOID **) &EdidOverride
                     );
    if (!EFI_ERROR (Status)) {
      //
      // Allocate double size of VESA_BIOS_EXTENSIONS_EDID_BLOCK_SIZE to avoid overflow
      //
      
      EdidOverrideDataBlock = AllocatePool (VESA_BIOS_EXTENSIONS_EDID_BLOCK_SIZE * 2);
      if (NULL == EdidOverrideDataBlock) {
        Status = EFI_OUT_OF_RESOURCES;
        goto Done;
      }
  
      Status = EdidOverride->GetEdid (
                               EdidOverride,
                               BiosVideoPrivate->Handle,
                               &EdidAttributes,
                               &EdidOverrideDataSize,
                               (UINT8 **) &EdidOverrideDataBlock
                               );
      if (!EFI_ERROR (Status)  &&
           EdidAttributes == 0 &&
           EdidOverrideDataSize != 0) {
        //
        // Succeeded to get EDID Override Data
        //
        DBG("EdidOverrideFound!\n");
        EdidOverrideFound = TRUE;
      }
    }
  
    if (!EdidOverrideFound || EdidAttributes == EFI_EDID_OVERRIDE_DONT_OVERRIDE) {
      //
      // If EDID Override data doesn't exist or EFI_EDID_OVERRIDE_DONT_OVERRIDE returned,
      // read EDID information through INT10 call
      //
    // INT 10 - VESA VBE/DC (Display Data Channel) - READ EDID
    //
    //    AX = 4F15h
    //    BL = 01h
    //    CX = 0000h  -- port number? =0 - main display
    //    DX = 0000h  -- block
    //       block 0 - VESA Structure
    //       block 1 - CEA Ext Structure
    //    ES:DI -> 128-byte buffer for EDID record (see #00127)
    // Return: AL = 4Fh if function supported
    //    AH = status
    //        00h successful
    //    ES:DI buffer filled
    //    01h failed (e.g. non-DDC monitor)
    //
  
      gBS->SetMem (&Regs, sizeof (Regs), 0);
      Regs.X.AX = VESA_BIOS_EXTENSIONS_EDID;
      Regs.X.BX = 1;
      Regs.X.CX = 0;
      Regs.X.DX = 0;
      Regs.X.ES = EFI_SEGMENT ((UINTN) BiosVideoPrivate->VbeEdidDataBlock);
      Regs.X.DI = EFI_OFFSET  ((UINTN) BiosVideoPrivate->VbeEdidDataBlock);
  
      BiosVideoPrivate->LegacyBios->Int86 (BiosVideoPrivate->LegacyBios, 0x10, &Regs);
      //
      // See if the VESA call succeeded
      //
      if (Regs.X.AX == VESA_BIOS_EXTENSIONS_STATUS_SUCCESS) {
        //
        // Set EDID Discovered Data
        //
        BiosVideoPrivate->EdidDiscovered.SizeOfEdid = VESA_BIOS_EXTENSIONS_EDID_BLOCK_SIZE;
        BiosVideoPrivate->EdidDiscovered.Edid = (UINT8 *) AllocateCopyPool (
            VESA_BIOS_EXTENSIONS_EDID_BLOCK_SIZE,
            BiosVideoPrivate->VbeEdidDataBlock
            );
  
        if (NULL == BiosVideoPrivate->EdidDiscovered.Edid) {
          Status = EFI_OUT_OF_RESOURCES;
          goto Done;
        }
  
        EdidFound = TRUE;
      }
    }
  
    if (EdidFound) {
      EdidActiveDataSize  = VESA_BIOS_EXTENSIONS_EDID_BLOCK_SIZE;
      EdidActiveDataBlock = BiosVideoPrivate->EdidDiscovered.Edid;
    } else if (EdidOverrideFound) {
      EdidActiveDataSize  = EdidOverrideDataSize;
      EdidActiveDataBlock = EdidOverrideDataBlock;
      EdidFound = TRUE;
    }
  
    if (EdidFound) {
      //
      // Parse EDID data structure to retrieve modes supported by monitor
      //
      if (ParseEdidData ((UINT8 *) EdidActiveDataBlock, &ValidEdidTiming)) {
        //
        // Copy EDID Override Data to EDID Active Data
        //
        BiosVideoPrivate->EdidActive.SizeOfEdid = (UINT32) EdidActiveDataSize;
        BiosVideoPrivate->EdidActive.Edid = (UINT8 *) AllocateCopyPool (
                                                        EdidActiveDataSize,
                                                        EdidActiveDataBlock
                                                        );
        if (NULL ==  BiosVideoPrivate->EdidActive.Edid) {
           Status = EFI_OUT_OF_RESOURCES;
          goto Done;
        }
      }
    } else {
      BiosVideoPrivate->EdidActive.SizeOfEdid = 0;
      BiosVideoPrivate->EdidActive.Edid = NULL;
      EdidFound = FALSE;
    }
  
    //
    // Walk through the mode list to see if there is at least one mode the is compatible with the EDID mode
    //
    ModeNumberPtr = (UINT16 *)
      (
        (((UINTN) BiosVideoPrivate->VbeInformationBlock->VideoModePtr & 0xffff0000) >> 12) |
          ((UINTN) BiosVideoPrivate->VbeInformationBlock->VideoModePtr & 0x0000ffff)
      );
  
    PreferMode = (UINTN)-1;
    ModeNumber = 0;
  
    //
    // ModeNumberPtr may be not 16-byte aligned, so ReadUnaligned16 is used to access the buffer pointed by ModeNumberPtr.
    //
    for (VbeModeNumber = ReadUnaligned16 (ModeNumberPtr);
         VbeModeNumber != VESA_BIOS_EXTENSIONS_END_OF_MODE_LIST;
         VbeModeNumber = ReadUnaligned16 (++ModeNumberPtr)) {
      //
      // Make sure this is a mode number defined by the VESA VBE specification.  If it isn'tm then skip this mode number.
      //
      if ((VbeModeNumber & VESA_BIOS_EXTENSIONS_MODE_NUMBER_VESA) == 0) {
        continue;
      }
      //
      // Get the information about the mode
      // INT 10 - VESA SuperVGA BIOS - GET SuperVGA MODE INFORMATION
      //
      //   AX = 4F01h
      //   CX = SuperVGA video mode (see #04082 for bitfields)
      //   ES:DI -> 256-byte buffer for mode information (see #00079)
      // Return: AL = 4Fh if function supported
      //   AH = status
      //      00h successful
      //    ES:DI buffer filled
      //      01h failed
      // Desc:  determine the attributes of the specified video mode
      //
      gBS->SetMem (&Regs, sizeof (Regs), 0);
      Regs.X.AX = VESA_BIOS_EXTENSIONS_RETURN_MODE_INFORMATION;
      Regs.X.CX = VbeModeNumber;
      gBS->SetMem (BiosVideoPrivate->VbeModeInformationBlock, sizeof (VESA_BIOS_EXTENSIONS_MODE_INFORMATION_BLOCK), 0);
      Regs.X.ES = EFI_SEGMENT ((UINTN) BiosVideoPrivate->VbeModeInformationBlock);
      Regs.X.DI = EFI_OFFSET ((UINTN) BiosVideoPrivate->VbeModeInformationBlock);
  
      BiosVideoPrivate->LegacyBios->Int86 (BiosVideoPrivate->LegacyBios, 0x10, &Regs);
  
      //
      // See if the call succeeded.  If it didn't, then try the next mode.
      //
      if (Regs.X.AX != VESA_BIOS_EXTENSIONS_STATUS_SUCCESS) {
        continue;
      }
      //
      // See if the mode supports color.  If it doesn't then try the next mode.
      //
      if ((BiosVideoPrivate->VbeModeInformationBlock->ModeAttributes & VESA_BIOS_EXTENSIONS_MODE_ATTRIBUTE_COLOR) == 0) {
        continue;
      }
      //
      // See if the mode supports graphics.  If it doesn't then try the next mode.
      //
      if ((BiosVideoPrivate->VbeModeInformationBlock->ModeAttributes & VESA_BIOS_EXTENSIONS_MODE_ATTRIBUTE_GRAPHICS) == 0) {
        continue;
      }
      //
      // See if the mode supports a linear frame buffer.  If it doesn't then try the next mode.
      //
      if ((BiosVideoPrivate->VbeModeInformationBlock->ModeAttributes & VESA_BIOS_EXTENSIONS_MODE_ATTRIBUTE_LINEAR_FRAME_BUFFER) == 0) {
        continue;
      }
      //
      // See if the mode supports 32 bit color.  If it doesn't then try the next mode.
      // 32 bit mode can be implemented by 24 Bits Per Pixels. Also make sure the
      // number of bits per pixel is a multiple of 8 or more than 32 bits per pixel
      //
      if (BiosVideoPrivate->VbeModeInformationBlock->BitsPerPixel < 24) {
        continue;
      }
  
      if (BiosVideoPrivate->VbeModeInformationBlock->BitsPerPixel > 32) {
        continue;
      }
  
      if ((BiosVideoPrivate->VbeModeInformationBlock->BitsPerPixel % 8) != 0) {
        continue;
      }
      //
      // See if the physical base pointer for the linear mode is valid.  If it isn't then try the next mode.
      //
      if (BiosVideoPrivate->VbeModeInformationBlock->PhysBasePtr == 0) {
        continue;
      }
      //
      // Skip modes not supported by the hardware.
      //
      if ((BiosVideoPrivate->VbeModeInformationBlock->ModeAttributes & VESA_BIOS_EXTENSIONS_MODE_ATTRIBUTE_HARDWARE) == 0) {
        //    MsgLog("not supported by hw ");
        continue;
      }
      //
      // dmazar: skip resolutions lower then 640x480.
      //
      if (BiosVideoPrivate->VbeModeInformationBlock->XResolution < 640 ||
        BiosVideoPrivate->VbeModeInformationBlock->YResolution < 480) {
        continue;
      }
      DBG("%3d %dx%d attr=%x - ok",
        ModeNumber,
        BiosVideoPrivate->VbeModeInformationBlock->XResolution,
        BiosVideoPrivate->VbeModeInformationBlock->YResolution,
        BiosVideoPrivate->VbeModeInformationBlock->ModeAttributes
        );
      ModeFound = TRUE;
      ModeConsideredWorking = FALSE;
      if (EdidFound && (ValidEdidTiming.ValidNumber > 0)) {
        //
        // EDID exist, check whether this mode match with any mode in EDID
        //
        Timing.HorizontalResolution = BiosVideoPrivate->VbeModeInformationBlock->XResolution;
        Timing.VerticalResolution = BiosVideoPrivate->VbeModeInformationBlock->YResolution;
        if (!SearchEdidTiming (&ValidEdidTiming, &Timing)) {
  //        MsgLog("Timing-\n");
          //ModeFound = FALSE;
          DBG(", edid-");
        } else {
  //        MsgLog("Timing+\n");
          //ModeFound = TRUE;
          DBG(", edid+");
          ModeConsideredWorking = TRUE;
        }
      }
  
      //
      // Select a reasonable mode to be set for current display mode
      //
      
    // it seems EDID doesn't contain these timing although they works
      if (BiosVideoPrivate->VbeModeInformationBlock->XResolution == 1024 &&
          BiosVideoPrivate->VbeModeInformationBlock->YResolution == 768
          )
      {
        ModeFound = TRUE;
        ModeConsideredWorking = TRUE;
        DBG(", 1024x768");
      }
      if (BiosVideoPrivate->VbeModeInformationBlock->XResolution == 800 &&
          BiosVideoPrivate->VbeModeInformationBlock->YResolution == 600
          )
      {
        ModeFound = TRUE;
        ModeConsideredWorking = TRUE;
        DBG(", 800x600");
      }
      if (BiosVideoPrivate->VbeModeInformationBlock->XResolution == 640 &&
          BiosVideoPrivate->VbeModeInformationBlock->YResolution == 480
          )
      {
        ModeFound = TRUE;
        ModeConsideredWorking = TRUE;
        DBG(", 640x480");
      }
      if (!ModeFound) {
        //
        // When no EDID exist, only select three possible resolutions, i.e. 1024x768, 800x600, 640x480
        //
        DBG(", not found???\n");
        continue;
      }
  
      //
      // Record the highest resolution mode to set later
      //
      if (ModeConsideredWorking) {
        DBG(", working");
      }
      if (ModeConsideredWorking &&
          (BiosVideoPrivate->VbeModeInformationBlock->XResolution >= HighestHorizontalResolution) &&
          (BiosVideoPrivate->VbeModeInformationBlock->YResolution >= HighestVerticalResolution))
      {
        HighestHorizontalResolution = BiosVideoPrivate->VbeModeInformationBlock->XResolution;
        HighestVerticalResolution = BiosVideoPrivate->VbeModeInformationBlock->YResolution;
        HighestResolutionMode = (UINT16)ModeNumber;
              DBG(", highest");
  //      MsgLog("best mode: %d\n", ModeNumber);
        PreferMode = HighestResolutionMode;
        DBG(", pref=%d", PreferMode);
      }
      //
      // Add mode to the list of available modes
      //
      ModeNumber ++;
      ModeBuffer = (BIOS_VIDEO_MODE_DATA *) AllocatePool (ModeNumber * sizeof (BIOS_VIDEO_MODE_DATA));
              
      if (NULL == ModeBuffer) {
        Status = EFI_OUT_OF_RESOURCES;
        goto Done;
      }
  
      if (ModeNumber > 1) {
        CopyMem (
          ModeBuffer,
          BiosVideoPrivate->ModeData,
          (ModeNumber - 1) * sizeof (BIOS_VIDEO_MODE_DATA)
          );
      }
  
      if (BiosVideoPrivate->ModeData != NULL) {
        FreePool (BiosVideoPrivate->ModeData);
      }
  
      CurrentModeData = &ModeBuffer[ModeNumber - 1];
      CurrentModeData->VbeModeNumber = VbeModeNumber;
      if (BiosVideoPrivate->VbeInformationBlock->VESAVersion >= VESA_BIOS_EXTENSIONS_VERSION_3_0) {
        CurrentModeData->BytesPerScanLine = BiosVideoPrivate->VbeModeInformationBlock->LinBytesPerScanLine;
        CurrentModeData->Red.Position = BiosVideoPrivate->VbeModeInformationBlock->LinRedFieldPosition;
        CurrentModeData->Red.Mask = (UINT8) ((1 << BiosVideoPrivate->VbeModeInformationBlock->LinRedMaskSize) - 1);
        CurrentModeData->Blue.Position = BiosVideoPrivate->VbeModeInformationBlock->LinBlueFieldPosition;
        CurrentModeData->Blue.Mask = (UINT8) ((1 << BiosVideoPrivate->VbeModeInformationBlock->LinBlueMaskSize) - 1);
        CurrentModeData->Green.Position = BiosVideoPrivate->VbeModeInformationBlock->LinGreenFieldPosition;
        CurrentModeData->Green.Mask = (UINT8) ((1 << BiosVideoPrivate->VbeModeInformationBlock->LinGreenMaskSize) - 1);
        CurrentModeData->Reserved.Position = BiosVideoPrivate->VbeModeInformationBlock->LinRsvdFieldPosition;
        CurrentModeData->Reserved.Mask = (UINT8) ((1 << BiosVideoPrivate->VbeModeInformationBlock->LinRsvdMaskSize) - 1);
      } else {
        CurrentModeData->BytesPerScanLine = BiosVideoPrivate->VbeModeInformationBlock->BytesPerScanLine;
        CurrentModeData->Red.Position = BiosVideoPrivate->VbeModeInformationBlock->RedFieldPosition;
        CurrentModeData->Red.Mask = (UINT8) ((1 << BiosVideoPrivate->VbeModeInformationBlock->RedMaskSize) - 1);
        CurrentModeData->Blue.Position = BiosVideoPrivate->VbeModeInformationBlock->BlueFieldPosition;
        CurrentModeData->Blue.Mask = (UINT8) ((1 << BiosVideoPrivate->VbeModeInformationBlock->BlueMaskSize) - 1);
        CurrentModeData->Green.Position = BiosVideoPrivate->VbeModeInformationBlock->GreenFieldPosition;
        CurrentModeData->Green.Mask = (UINT8) ((1 << BiosVideoPrivate->VbeModeInformationBlock->GreenMaskSize) - 1);
        CurrentModeData->Reserved.Position = BiosVideoPrivate->VbeModeInformationBlock->RsvdFieldPosition;
        CurrentModeData->Reserved.Mask = (UINT8) ((1 << BiosVideoPrivate->VbeModeInformationBlock->RsvdMaskSize) - 1);
      }
  
      CurrentModeData->PixelFormat = PixelBitMask;
      if ((BiosVideoPrivate->VbeModeInformationBlock->BitsPerPixel == 32) &&
          (CurrentModeData->Red.Mask == 0xff) && (CurrentModeData->Green.Mask == 0xff) && (CurrentModeData->Blue.Mask == 0xff)) {
        if ((CurrentModeData->Red.Position == 0) && (CurrentModeData->Green.Position == 8) && (CurrentModeData->Blue.Position == 16)) {
          CurrentModeData->PixelFormat = PixelRedGreenBlueReserved8BitPerColor;
        } else if ((CurrentModeData->Blue.Position == 0) && (CurrentModeData->Green.Position == 8) && (CurrentModeData->Red.Position == 16)) {
          CurrentModeData->PixelFormat = PixelBlueGreenRedReserved8BitPerColor;
        }
      }
  
      CurrentModeData->PixelBitMask.RedMask = ((UINT32) CurrentModeData->Red.Mask) << CurrentModeData->Red.Position;
      CurrentModeData->PixelBitMask.GreenMask = ((UINT32) CurrentModeData->Green.Mask) << CurrentModeData->Green.Position;
      CurrentModeData->PixelBitMask.BlueMask = ((UINT32) CurrentModeData->Blue.Mask) << CurrentModeData->Blue.Position;
      CurrentModeData->PixelBitMask.ReservedMask = ((UINT32) CurrentModeData->Reserved.Mask) << CurrentModeData->Reserved.Position;
  
      CurrentModeData->LinearFrameBuffer = (VOID *) (UINTN)BiosVideoPrivate->VbeModeInformationBlock->PhysBasePtr;
      CurrentModeData->FrameBufferSize = BiosVideoPrivate->VbeInformationBlock->TotalMemory * 64 * 1024;
      CurrentModeData->HorizontalResolution = BiosVideoPrivate->VbeModeInformationBlock->XResolution;
      CurrentModeData->VerticalResolution = BiosVideoPrivate->VbeModeInformationBlock->YResolution;
  
      CurrentModeData->BitsPerPixel  = BiosVideoPrivate->VbeModeInformationBlock->BitsPerPixel;
  
      BiosVideoPrivate->ModeData = ModeBuffer;
          DBG("\n");
    }
    //
    // Check to see if we found any modes that are compatible with GRAPHICS OUTPUT
    //
    if (ModeNumber == 0) {
      Status = EFI_DEVICE_ERROR;
      goto Done;
    }
  
    //
    // Assign Gop's Blt function
    //
    BiosVideoPrivate->GraphicsOutput.Blt     = BiosVideoGraphicsOutputVbeBlt;
  
    BiosVideoPrivate->GraphicsOutput.Mode->MaxMode = (UINT32) ModeNumber;
    //
    // Current mode is unknow till now, set it to an invalid mode.
    //
    BiosVideoPrivate->GraphicsOutput.Mode->Mode = GRAPHICS_OUTPUT_INVALIDE_MODE_NUMBER;
  
    //
    // Find the best mode to initialize
    //
  /*  if ((PcdGet32 (PcdVideoHorizontalResolution) == 0x0) || (PcdGet32 (PcdVideoVerticalResolution) == 0x0)) {
      DEBUG_CODE (
        BIOS_VIDEO_MODE_DATA    *ModeData;
        ModeData = &BiosVideoPrivate->ModeData[HighestResolutionMode];
        DEBUG ((EFI_D_INFO, "BiosVideo set highest resolution %d x %d\n",
                ModeData->HorizontalResolution, ModeData->VerticalResolution));
      );
      PreferMode = HighestResolutionMode;
    } */
  //  PreferMode = HighestResolutionMode;
    Status = BiosVideoGraphicsOutputSetMode (&BiosVideoPrivate->GraphicsOutput, (UINT32) PreferMode);
      DBG(" - SetMode pref %d (%d) = %r\n", PreferMode, (UINT32) PreferMode, Status);
    if (EFI_ERROR (Status)) {
      for (PreferMode = 0; PreferMode < ModeNumber; PreferMode ++) {
        Status = BiosVideoGraphicsOutputSetMode (
                  &BiosVideoPrivate->GraphicsOutput,
                  (UINT32) PreferMode
                  );
              DBG(" - SetMode pref %d (%d) = %r\n", PreferMode, (UINT32) PreferMode, Status);
        if (!EFI_ERROR (Status)) {
          break;
        }
      }
      if (PreferMode == ModeNumber) {
        //
        // None mode is set successfully.
        //
        PreferMode = HighestResolutionMode;
      }
    }
  
  Done:
    //
    // If there was an error, then free the mode structure
    //
    if (EFI_ERROR (Status)) {
      if (BiosVideoPrivate->ModeData != NULL) {
        FreePool (BiosVideoPrivate->ModeData);
        BiosVideoPrivate->ModeData  = NULL;
        BiosVideoPrivate->MaxMode   = 0;
      }
      if (EdidOverrideDataBlock != NULL) {
        FreePool (EdidOverrideDataBlock);
      }
    }
  
    return Status;
  }
  
  /**
    Check for VGA device.
  
    @param  BiosVideoPrivate       Pointer to BIOS_VIDEO_DEV structure
  
    @retval EFI_SUCCESS            Standard VGA device found
  
  **/
  EFI_STATUS
  BiosVideoCheckForVga (
    IN OUT BIOS_VIDEO_DEV  *BiosVideoPrivate
    )
  {
    EFI_STATUS            Status;
    BIOS_VIDEO_MODE_DATA  *ModeBuffer;
  
    Status = EFI_UNSUPPORTED;
  
    //
    // Assign Gop's Blt function
    //
    BiosVideoPrivate->GraphicsOutput.Blt     = BiosVideoGraphicsOutputVgaBlt;
  
    //
    // Add mode to the list of available modes
    // caller should guarantee that Mode has been allocated.
    //
  //  ASSERT (BiosVideoPrivate->GraphicsOutput.Mode != NULL);
    if (!BiosVideoPrivate->GraphicsOutput.Mode) {
      goto Done;
    }
    BiosVideoPrivate->GraphicsOutput.Mode->MaxMode = 1;
  
    ModeBuffer = (BIOS_VIDEO_MODE_DATA *) AllocatePool (
                                            sizeof (BIOS_VIDEO_MODE_DATA)
                                            );
    if (NULL == ModeBuffer) {
      Status = EFI_OUT_OF_RESOURCES;
      goto Done;
    }
  
    ModeBuffer->VbeModeNumber         = 0x0012;
    ModeBuffer->BytesPerScanLine      = 640;
    ModeBuffer->LinearFrameBuffer     = (VOID *) (UINTN) (0xa0000);
  //  ModeBuffer->FrameBufferSize       = 0;
    ModeBuffer->HorizontalResolution  = 640;
    ModeBuffer->VerticalResolution    = 480;
    ModeBuffer->PixelFormat           = PixelBltOnly;
    ModeBuffer->BitsPerPixel          = 8;
    ModeBuffer->ColorDepth            = 32;
    ModeBuffer->RefreshRate           = 60;
  
    BiosVideoPrivate->ModeData = ModeBuffer;
  
    //
    // Test to see if the Video Adapter support the 640x480 16 color mode
    //
    BiosVideoPrivate->GraphicsOutput.Mode->Mode = GRAPHICS_OUTPUT_INVALIDE_MODE_NUMBER;
    Status = BiosVideoGraphicsOutputSetMode (&BiosVideoPrivate->GraphicsOutput, 0);
  
  Done:
    //
    // If there was an error, then free the mode structure
    //
    if (EFI_ERROR (Status)) {
      if (BiosVideoPrivate->ModeData != NULL) {
        FreePool (BiosVideoPrivate->ModeData);
        BiosVideoPrivate->ModeData = NULL;
      }
      if (BiosVideoPrivate->GraphicsOutput.Mode != NULL) {
        if (BiosVideoPrivate->GraphicsOutput.Mode->Info != NULL) {
          FreePool (BiosVideoPrivate->GraphicsOutput.Mode->Info);
          BiosVideoPrivate->GraphicsOutput.Mode->Info = NULL;
        }
        FreePool (BiosVideoPrivate->GraphicsOutput.Mode);
        BiosVideoPrivate->GraphicsOutput.Mode = NULL;
      }
    }
    return Status;
  }
  
  //
  // Graphics Output Protocol Member Functions for VESA BIOS Extensions
  //
  
  /**
    Graphics Output protocol interface to get video mode.
  
    @param  This                   Protocol instance pointer.
    @param  ModeNumber             The mode number to return information on.
    @param  SizeOfInfo             A pointer to the size, in bytes, of the Info
                                   buffer.
    @param  Info                   Caller allocated buffer that returns information
                                   about ModeNumber.
  
    @retval EFI_SUCCESS            Mode information returned.
    @retval EFI_DEVICE_ERROR       A hardware error occurred trying to retrieve the
                                   video mode.
    @retval EFI_NOT_STARTED        Video display is not initialized. Call SetMode ()
    @retval EFI_INVALID_PARAMETER  One of the input args was NULL.
  
  **/
  EFI_STATUS
  EFIAPI
  BiosVideoGraphicsOutputQueryMode (
    IN  EFI_GRAPHICS_OUTPUT_PROTOCOL          *This,
    IN  UINT32                                ModeNumber,
    OUT UINTN                                 *SizeOfInfo,
    OUT EFI_GRAPHICS_OUTPUT_MODE_INFORMATION  **Info
    )
  {
    BIOS_VIDEO_DEV        *BiosVideoPrivate;
    BIOS_VIDEO_MODE_DATA  *ModeData;
  
    BiosVideoPrivate = BIOS_VIDEO_DEV_FROM_GRAPHICS_OUTPUT_THIS (This);
  
    if (BiosVideoPrivate->HardwareNeedsStarting) {
      REPORT_STATUS_CODE_WITH_DEVICE_PATH (
        EFI_ERROR_CODE | EFI_ERROR_MINOR,
        EFI_PERIPHERAL_LOCAL_CONSOLE | EFI_P_EC_OUTPUT_ERROR,
        BiosVideoPrivate->GopDevicePath
        );
      return EFI_NOT_STARTED;
    }
  
    if (This == NULL || Info == NULL || SizeOfInfo == NULL || ModeNumber >= This->Mode->MaxMode) {
      return EFI_INVALID_PARAMETER;
    }
  
    *Info = (EFI_GRAPHICS_OUTPUT_MODE_INFORMATION *) AllocatePool (sizeof (EFI_GRAPHICS_OUTPUT_MODE_INFORMATION));
    if (NULL == *Info) {
      return EFI_OUT_OF_RESOURCES;
    }
  
    *SizeOfInfo = sizeof (EFI_GRAPHICS_OUTPUT_MODE_INFORMATION);
  
    ModeData = &BiosVideoPrivate->ModeData[ModeNumber];
    (*Info)->Version = 0;
    (*Info)->HorizontalResolution = ModeData->HorizontalResolution;
    (*Info)->VerticalResolution   = ModeData->VerticalResolution;
    (*Info)->PixelFormat = ModeData->PixelFormat;
    CopyMem (&((*Info)->PixelInformation), &(ModeData->PixelBitMask), sizeof(ModeData->PixelBitMask));
  
    (*Info)->PixelsPerScanLine =  (ModeData->BytesPerScanLine * 8) / ModeData->BitsPerPixel;
  
    return EFI_SUCCESS;
  }
  
  /**
    Worker function to set video mode.
  
    @param  BiosVideoPrivate       Instance of BIOS_VIDEO_DEV.
    @param  ModeData               The mode data to be set.
    @param  DevicePath             Pointer to Device Path Protocol.
  
    @retval EFI_SUCCESS            Graphics mode was changed.
    @retval EFI_DEVICE_ERROR       The device had an error and could not complete the
                                   request.
    @retval EFI_UNSUPPORTED        ModeNumber is not supported by this device.
  
  **/
  EFI_STATUS
  BiosVideoSetModeWorker (
    IN  BIOS_VIDEO_DEV               *BiosVideoPrivate,
    IN  BIOS_VIDEO_MODE_DATA         *ModeData,
    IN  EFI_DEVICE_PATH_PROTOCOL     *DevicePath
    )
  {
   // EFI_STATUS              Status;
    EFI_IA32_REGISTER_SET   Regs;
  
    if (BiosVideoPrivate->LineBuffer != NULL) {
      FreePool (BiosVideoPrivate->LineBuffer);
    }
  
    if (BiosVideoPrivate->VgaFrameBuffer != NULL) {
      FreePool (BiosVideoPrivate->VgaFrameBuffer);
    }
  
    if (BiosVideoPrivate->VbeFrameBuffer != NULL) {
      FreePool (BiosVideoPrivate->VbeFrameBuffer);
    }
  
    BiosVideoPrivate->LineBuffer = (UINT8 *) AllocatePool (ModeData->BytesPerScanLine);
    if (NULL == BiosVideoPrivate->LineBuffer) {
      return EFI_OUT_OF_RESOURCES;
    }
    //
    // Clear all registers
    //
    gBS->SetMem (&Regs, sizeof (Regs), 0);
  
    if (ModeData->VbeModeNumber < 0x100) {
      //
      // Allocate a working buffer for BLT operations to the VGA frame buffer
      //
      BiosVideoPrivate->VgaFrameBuffer = (UINT8 *) AllocatePool (4 * 480 * 80);
      if (NULL == BiosVideoPrivate->VgaFrameBuffer) {
        return EFI_OUT_OF_RESOURCES;
      }
      //
      // Set VGA Mode
      //
      Regs.X.AX = ModeData->VbeModeNumber;
      BiosVideoPrivate->LegacyBios->Int86 (BiosVideoPrivate->LegacyBios, 0x10, &Regs);
  
    } else {
      //
      // Allocate a working buffer for BLT operations to the VBE frame buffer
      //
      BiosVideoPrivate->VbeFrameBuffer =
        (EFI_GRAPHICS_OUTPUT_BLT_PIXEL *) AllocatePool (ModeData->BytesPerScanLine * ModeData->VerticalResolution);
      if (NULL == BiosVideoPrivate->VbeFrameBuffer) {
        return EFI_OUT_OF_RESOURCES;
      }
      //
      // Set VBE mode
      //
      Regs.X.AX = VESA_BIOS_EXTENSIONS_SET_MODE;
      Regs.X.BX = (UINT16) (ModeData->VbeModeNumber | VESA_BIOS_EXTENSIONS_MODE_NUMBER_LINEAR_FRAME_BUFFER);
      gBS->SetMem (BiosVideoPrivate->VbeCrtcInformationBlock, sizeof (VESA_BIOS_EXTENSIONS_CRTC_INFORMATION_BLOCK), 0);
      Regs.X.ES = EFI_SEGMENT ((UINTN) BiosVideoPrivate->VbeCrtcInformationBlock);
      Regs.X.DI = EFI_OFFSET ((UINTN) BiosVideoPrivate->VbeCrtcInformationBlock);
      BiosVideoPrivate->LegacyBios->Int86 (BiosVideoPrivate->LegacyBios, 0x10, &Regs);
  
      //
      // Check to see if the call succeeded
      //
      if (Regs.X.AX != VESA_BIOS_EXTENSIONS_STATUS_SUCCESS) {
        return EFI_DEVICE_ERROR;
      }
      //
      // Initialize the state of the VbeFrameBuffer
      //
  /*    Status = BiosVideoPrivate->PciIo->Mem.Read (
                                              BiosVideoPrivate->PciIo,
                                              EfiPciIoWidthUint32,
                                              EFI_PCI_IO_PASS_THROUGH_BAR,
                                              (UINT64) (UINTN) ModeData->LinearFrameBuffer,
                                              (ModeData->BytesPerScanLine * ModeData->VerticalResolution) >> 2,
                                              BiosVideoPrivate->VbeFrameBuffer
                                              );
      if (EFI_ERROR (Status)) {
        return Status;
      }*/
    }
  
    return EFI_SUCCESS;
  }
  
  /**
    Graphics Output protocol interface to set video mode.
  
    @param  This                   Protocol instance pointer.
    @param  ModeNumber             The mode number to be set.
  
    @retval EFI_SUCCESS            Graphics mode was changed.
    @retval EFI_DEVICE_ERROR       The device had an error and could not complete the
                                   request.
    @retval EFI_UNSUPPORTED        ModeNumber is not supported by this device.
  
  **/
  EFI_STATUS
  EFIAPI
  BiosVideoGraphicsOutputSetMode (
    IN  EFI_GRAPHICS_OUTPUT_PROTOCOL * This,
    IN  UINT32                       ModeNumber
    )
  {
    EFI_STATUS              Status;
    BIOS_VIDEO_DEV          *BiosVideoPrivate;
    BIOS_VIDEO_MODE_DATA    *ModeData;
  //  EFI_GRAPHICS_OUTPUT_BLT_PIXEL Background;
    UINTN                   DataSize;
  
    if (This == NULL) {
      return EFI_INVALID_PARAMETER;
    }
  
    BiosVideoPrivate = BIOS_VIDEO_DEV_FROM_GRAPHICS_OUTPUT_THIS (This);
  
    ModeData = &BiosVideoPrivate->ModeData[ModeNumber];
    DBG("CsmVideo: New mode: %d %dx%d", ModeNumber, ModeData->HorizontalResolution, ModeData->VerticalResolution);
  
    if (ModeNumber >= This->Mode->MaxMode) {
      DBG("- EFI_UNSUPPORTED\n");
      return EFI_UNSUPPORTED;
    }
    
    //
    // Boot speedup: Check if RT var "BiosVideoBlockSwitchMode" is set.
    // If yes, then do not switch mode.
    //
    DataSize = 0;
    if (gBiosVideoBlockSwitchMode) {
      Status = gRT->GetVariable (L"BiosVideoBlockSwitchMode", &gEfiGlobalVariableGuid, NULL, &DataSize, NULL);
      //DBG("BiosVideoGraphicsOutputSetMode: GetVariable BiosVideoBlockSwitchMode: %r\n", Status);
      if (Status == EFI_BUFFER_TOO_SMALL) {
        // var exists - just exit
        DBG(" - blocking that switch\n");
        return EFI_SUCCESS;
      }
      // var is cleared by Clover - clear our flag to avoid calling of
      // gRT->GetVariable() all the time
      gBiosVideoBlockSwitchMode = FALSE;
    }
    
    if (ModeNumber == This->Mode->Mode) {
      //
      // Clear screen to black
      //    
  /*    ZeroMem (&Background, sizeof (EFI_GRAPHICS_OUTPUT_BLT_PIXEL));
      BiosVideoGraphicsOutputVbeBlt (
                          This,
                          &Background,
                          EfiBltVideoFill,
                          0,
                          0,
                          0,
                          0,
                          ModeData->HorizontalResolution,
                          ModeData->VerticalResolution,
                          0
      );
      DBG(" - already set\n"); */
      return EFI_SUCCESS;
    }
  
    Status = BiosVideoSetModeWorker (BiosVideoPrivate, ModeData, BiosVideoPrivate->GopDevicePath);
    if (EFI_ERROR (Status)) {
      DBG(" - %r\n", Status);
      return Status;
    }
  
    This->Mode->Mode = ModeNumber;
    This->Mode->Info->Version = 0;
    This->Mode->Info->HorizontalResolution = ModeData->HorizontalResolution;
    This->Mode->Info->VerticalResolution = ModeData->VerticalResolution;
    This->Mode->Info->PixelFormat = ModeData->PixelFormat;
    CopyMem (&(This->Mode->Info->PixelInformation), &(ModeData->PixelBitMask), sizeof (ModeData->PixelBitMask));
    This->Mode->Info->PixelsPerScanLine =  (ModeData->BytesPerScanLine * 8) / ModeData->BitsPerPixel;
    This->Mode->SizeOfInfo = sizeof(EFI_GRAPHICS_OUTPUT_MODE_INFORMATION);
  
    //
    // Frame BufferSize remain unchanged
    //
    This->Mode->FrameBufferBase = (EFI_PHYSICAL_ADDRESS) (UINTN) ModeData->LinearFrameBuffer;
    This->Mode->FrameBufferSize = ModeData->FrameBufferSize;
  
    BiosVideoPrivate->HardwareNeedsStarting = FALSE;
  
    DBG(" - set\n");
    return EFI_SUCCESS;
  }
  
  /**
    Update physical frame buffer, copy 4 bytes block, then copy remaining bytes.
  
    @param   PciIo              The pointer of EFI_PCI_IO_PROTOCOL
    @param   VbeBuffer          The data to transfer to screen
    @param   MemAddress         Physical frame buffer base address
    @param   DestinationX       The X coordinate of the destination for BltOperation
    @param   DestinationY       The Y coordinate of the destination for BltOperation
    @param   TotalBytes         The total bytes of copy
    @param   VbePixelWidth      Bytes per pixel
    @param   BytesPerScanLine   Bytes per scan line
  
  **/
  VOID
  CopyVideoBuffer (
    IN  EFI_PCI_IO_PROTOCOL   *PciIo,
    IN  UINT8                 *VbeBuffer,
    IN  VOID                  *MemAddress,
    IN  UINTN                 DestinationX,
    IN  UINTN                 DestinationY,
    IN  UINTN                 TotalBytes,
    IN  UINT32                VbePixelWidth,
    IN  UINTN                 BytesPerScanLine
    )
  {
    UINTN                 FrameBufferAddr;
    UINTN                 CopyBlockNum;
    UINTN                 RemainingBytes;
    UINTN                 UnalignedBytes;
    EFI_STATUS            Status;
  
    FrameBufferAddr = (UINTN) MemAddress + (DestinationY * BytesPerScanLine) + DestinationX * VbePixelWidth;
  
    //
    // If TotalBytes is less than 4 bytes, only start byte copy.
    //
    if (TotalBytes < 4) {
      Status = PciIo->Mem.Write (
                       PciIo,
                       EfiPciIoWidthUint8,
                       EFI_PCI_IO_PASS_THROUGH_BAR,
                       (UINT64) FrameBufferAddr,
                       TotalBytes,
                       VbeBuffer
                       );
   //   ASSERT_EFI_ERROR (Status);
      return;
    }
  
    //
    // If VbeBuffer is not 4-byte aligned, start byte copy.
    //
    UnalignedBytes  = (4 - ((UINTN) VbeBuffer & 0x3)) & 0x3;
  
    if (UnalignedBytes != 0) {
      Status = PciIo->Mem.Write (
                       PciIo,
                       EfiPciIoWidthUint8,
                       EFI_PCI_IO_PASS_THROUGH_BAR,
                       (UINT64) FrameBufferAddr,
                       UnalignedBytes,
                       VbeBuffer
                       );
   //   ASSERT_EFI_ERROR (Status);
      if (EFI_ERROR (Status)) {
        return;
      }
      FrameBufferAddr += UnalignedBytes;
      VbeBuffer       += UnalignedBytes;
    }
  
    //
    // Calculate 4-byte block count and remaining bytes.
    //
    CopyBlockNum   = (TotalBytes - UnalignedBytes) >> 2;
    RemainingBytes = (TotalBytes - UnalignedBytes) &  3;
  
    //
    // Copy 4-byte block and remaining bytes to physical frame buffer.
    //
    if (CopyBlockNum != 0) {
      Status = PciIo->Mem.Write (
                      PciIo,
                      EfiPciIoWidthUint32,
                      EFI_PCI_IO_PASS_THROUGH_BAR,
                      (UINT64) FrameBufferAddr,
                      CopyBlockNum,
                      VbeBuffer
                      );
  //    ASSERT_EFI_ERROR (Status);
      if (EFI_ERROR (Status)) {
        return;
      }
    }
  
    if (RemainingBytes != 0) {
      FrameBufferAddr += (CopyBlockNum << 2);
      VbeBuffer       += (CopyBlockNum << 2);
      Status = PciIo->Mem.Write (
                      PciIo,
                      EfiPciIoWidthUint8,
                      EFI_PCI_IO_PASS_THROUGH_BAR,
                      (UINT64) FrameBufferAddr,
                      RemainingBytes,
                      VbeBuffer
                      );
  //    ASSERT_EFI_ERROR (Status);
      if (EFI_ERROR (Status)) {
        return;
      }
    }
  }
  
  /**
    Worker function to block transfer for VBE device.
  
    @param  BiosVideoPrivate       Instance of BIOS_VIDEO_DEV
    @param  BltBuffer              The data to transfer to screen
    @param  BltOperation           The operation to perform
    @param  SourceX                The X coordinate of the source for BltOperation
    @param  SourceY                The Y coordinate of the source for BltOperation
    @param  DestinationX           The X coordinate of the destination for
                                   BltOperation
    @param  DestinationY           The Y coordinate of the destination for
                                   BltOperation
    @param  Width                  The width of a rectangle in the blt rectangle in
                                   pixels
    @param  Height                 The height of a rectangle in the blt rectangle in
                                   pixels
    @param  Delta                  Not used for EfiBltVideoFill and
                                   EfiBltVideoToVideo operation. If a Delta of 0 is
                                   used, the entire BltBuffer will be operated on. If
                                   a subrectangle of the BltBuffer is used, then
                                   Delta represents the number of bytes in a row of
                                   the BltBuffer.
    @param  Mode                   Mode data.
  
    @retval EFI_INVALID_PARAMETER  Invalid parameter passed in
    @retval EFI_SUCCESS            Blt operation success
  
  **/
  EFI_STATUS
  BiosVideoVbeBltWorker (
    IN  BIOS_VIDEO_DEV                     *BiosVideoPrivate,
    IN  EFI_GRAPHICS_OUTPUT_BLT_PIXEL      *BltBuffer, OPTIONAL
    IN  EFI_GRAPHICS_OUTPUT_BLT_OPERATION  BltOperation,
    IN  UINTN                              SourceX,
    IN  UINTN                              SourceY,
    IN  UINTN                              DestinationX,
    IN  UINTN                              DestinationY,
    IN  UINTN                              Width,
    IN  UINTN                              Height,
    IN  UINTN                              Delta,
    IN  BIOS_VIDEO_MODE_DATA               *Mode
    )
  {
    EFI_PCI_IO_PROTOCOL            *PciIo;
    EFI_TPL                        OriginalTPL;
    UINTN                          DstY;
    UINTN                          SrcY;
    UINTN                          DstX;
    EFI_GRAPHICS_OUTPUT_BLT_PIXEL  *Blt;
    VOID                           *MemAddress;
    EFI_GRAPHICS_OUTPUT_BLT_PIXEL  *VbeFrameBuffer;
    UINTN                          BytesPerScanLine;
    UINTN                          Index;
    UINT8                          *VbeBuffer;
    UINT8                          *VbeBuffer1;
    UINT8                          *BltUint8;
    UINT32                         VbePixelWidth;
    UINT32                         Pixel;
    UINTN                          TotalBytes;
  
    PciIo             = BiosVideoPrivate->PciIo;
  
    VbeFrameBuffer    = BiosVideoPrivate->VbeFrameBuffer;
    MemAddress        = Mode->LinearFrameBuffer;
    BytesPerScanLine  = Mode->BytesPerScanLine;
    VbePixelWidth     = Mode->BitsPerPixel / 8;
    BltUint8          = (UINT8 *) BltBuffer;
    TotalBytes        = Width * VbePixelWidth;
  
    if (((UINTN) BltOperation) >= EfiGraphicsOutputBltOperationMax) {
      return EFI_INVALID_PARAMETER;
    }
  
    if (Width == 0 || Height == 0) {
      return EFI_INVALID_PARAMETER;
    }
    //
    // We need to fill the Virtual Screen buffer with the blt data.
    // The virtual screen is upside down, as the first row is the bootom row of
    // the image.
    //
    if (BltOperation == EfiBltVideoToBltBuffer) {
      //
      // Video to BltBuffer: Source is Video, destination is BltBuffer
      //
      if (SourceY + Height > Mode->VerticalResolution) {
        return EFI_INVALID_PARAMETER;
      }
  
      if (SourceX + Width > Mode->HorizontalResolution) {
        return EFI_INVALID_PARAMETER;
      }
    } else {
      //
      // BltBuffer to Video: Source is BltBuffer, destination is Video
      //
      if (DestinationY + Height > Mode->VerticalResolution) {
        return EFI_INVALID_PARAMETER;
      }
  
      if (DestinationX + Width > Mode->HorizontalResolution) {
        return EFI_INVALID_PARAMETER;
      }
    }
    //
    // If Delta is zero, then the entire BltBuffer is being used, so Delta
    // is the number of bytes in each row of BltBuffer.  Since BltBuffer is Width pixels size,
    // the number of bytes in each row can be computed.
    //
    if (Delta == 0) {
      Delta = Width * sizeof (EFI_GRAPHICS_OUTPUT_BLT_PIXEL);
    }
    //
    // We have to raise to TPL Notify, so we make an atomic write the frame buffer.
    // We would not want a timer based event (Cursor, ...) to come in while we are
    // doing this operation.
    //
    OriginalTPL = gBS->RaiseTPL (TPL_NOTIFY);
  
    switch (BltOperation) {
    case EfiBltVideoToBltBuffer:
      for (SrcY = SourceY, DstY = DestinationY; DstY < (Height + DestinationY); SrcY++, DstY++) {
        Blt = (EFI_GRAPHICS_OUTPUT_BLT_PIXEL *) (BltUint8 + DstY * Delta + DestinationX * sizeof (EFI_GRAPHICS_OUTPUT_BLT_PIXEL));
        //
        // Shuffle the packed bytes in the hardware buffer to match EFI_GRAPHICS_OUTPUT_BLT_PIXEL
        //
        VbeBuffer = ((UINT8 *) VbeFrameBuffer + (SrcY * BytesPerScanLine + SourceX * VbePixelWidth));
        for (DstX = DestinationX; DstX < (Width + DestinationX); DstX++) {
          Pixel         = VbeBuffer[0] | VbeBuffer[1] << 8 | VbeBuffer[2] << 16 | VbeBuffer[3] << 24;
          Blt->Red      = (UINT8) ((Pixel >> Mode->Red.Position) & Mode->Red.Mask);
          Blt->Blue     = (UINT8) ((Pixel >> Mode->Blue.Position) & Mode->Blue.Mask);
          Blt->Green    = (UINT8) ((Pixel >> Mode->Green.Position) & Mode->Green.Mask);
          Blt->Reserved = 0;
          Blt++;
          VbeBuffer += VbePixelWidth;
        }
  
      }
      break;
  
    case EfiBltVideoToVideo:
      for (Index = 0; Index < Height; Index++) {
        if (DestinationY <= SourceY) {
          SrcY  = SourceY + Index;
          DstY  = DestinationY + Index;
        } else {
          SrcY  = SourceY + Height - Index - 1;
          DstY  = DestinationY + Height - Index - 1;
        }
  
        VbeBuffer   = ((UINT8 *) VbeFrameBuffer + DstY * BytesPerScanLine + DestinationX * VbePixelWidth);
        VbeBuffer1  = ((UINT8 *) VbeFrameBuffer + SrcY * BytesPerScanLine + SourceX * VbePixelWidth);
  
        gBS->CopyMem (
              VbeBuffer,
              VbeBuffer1,
              TotalBytes
              );
  
        //
        // Update physical frame buffer.
        //
        CopyVideoBuffer (
          PciIo,
          VbeBuffer,
          MemAddress,
          DestinationX,
          DstY,
          TotalBytes,
          VbePixelWidth,
          BytesPerScanLine
          );
      }
      break;
  
    case EfiBltVideoFill:
      VbeBuffer = (UINT8 *) ((UINTN) VbeFrameBuffer + (DestinationY * BytesPerScanLine) + DestinationX * VbePixelWidth);
      Blt       = (EFI_GRAPHICS_OUTPUT_BLT_PIXEL *) BltUint8;
      //
      // Shuffle the RGB fields in EFI_GRAPHICS_OUTPUT_BLT_PIXEL to match the hardware buffer
      //
      Pixel = ((Blt->Red & Mode->Red.Mask) << Mode->Red.Position) |
        (
          (Blt->Green & Mode->Green.Mask) <<
          Mode->Green.Position
        ) |
            ((Blt->Blue & Mode->Blue.Mask) << Mode->Blue.Position);
  
      for (Index = 0; Index < Width; Index++) {
   /*     gBS->CopyMem (
              VbeBuffer,
              &Pixel,
              VbePixelWidth
              ); */
        *(UINT32*)VbeBuffer = Pixel;
        VbeBuffer += VbePixelWidth;
      }
  
      VbeBuffer = (UINT8 *) ((UINTN) VbeFrameBuffer + (DestinationY * BytesPerScanLine) + DestinationX * VbePixelWidth);
      for (DstY = DestinationY + 1; DstY < (Height + DestinationY); DstY++) {
        gBS->CopyMem (
              (VOID *) ((UINTN) VbeFrameBuffer + (DstY * BytesPerScanLine) + DestinationX * VbePixelWidth),
              VbeBuffer,
              TotalBytes
              );
      }
  
      for (DstY = DestinationY; DstY < (Height + DestinationY); DstY++) {
        //
        // Update physical frame buffer.
        //
        CopyVideoBuffer (
          PciIo,
          VbeBuffer,
          MemAddress,
          DestinationX,
          DstY,
          TotalBytes,
          VbePixelWidth,
          BytesPerScanLine
          );
      }
      break;
  
    case EfiBltBufferToVideo:
      for (SrcY = SourceY, DstY = DestinationY; SrcY < (Height + SourceY); SrcY++, DstY++) {
        Blt       = (EFI_GRAPHICS_OUTPUT_BLT_PIXEL *) (BltUint8 + (SrcY * Delta) + (SourceX) * sizeof (EFI_GRAPHICS_OUTPUT_BLT_PIXEL));
        VbeBuffer = ((UINT8 *) VbeFrameBuffer + (DstY * BytesPerScanLine + DestinationX * VbePixelWidth));
        for (DstX = DestinationX; DstX < (Width + DestinationX); DstX++) {
          //
          // Shuffle the RGB fields in EFI_GRAPHICS_OUTPUT_BLT_PIXEL to match the hardware buffer
          //
          Pixel = ((Blt->Red & Mode->Red.Mask) << Mode->Red.Position) |
            ((Blt->Green & Mode->Green.Mask) << Mode->Green.Position) |
              ((Blt->Blue & Mode->Blue.Mask) << Mode->Blue.Position);
     /*     gBS->CopyMem (
                VbeBuffer,
                &Pixel,
                VbePixelWidth
                ); */
          *(UINT32*)VbeBuffer = Pixel;
          Blt++;
          VbeBuffer += VbePixelWidth;
        }
  
        VbeBuffer = ((UINT8 *) VbeFrameBuffer + (DstY * BytesPerScanLine + DestinationX * VbePixelWidth));
  
        //
        // Update physical frame buffer.
        //
        CopyVideoBuffer (
          PciIo,
          VbeBuffer,
          MemAddress,
          DestinationX,
          DstY,
          TotalBytes,
          VbePixelWidth,
          BytesPerScanLine
          );
      }
      break;
  
      default: ;
    }
  
    gBS->RestoreTPL (OriginalTPL);
  
    return EFI_SUCCESS;
  }
  
  /**
    Graphics Output protocol instance to block transfer for VBE device.
  
    @param  This                   Pointer to Graphics Output protocol instance
    @param  BltBuffer              The data to transfer to screen
    @param  BltOperation           The operation to perform
    @param  SourceX                The X coordinate of the source for BltOperation
    @param  SourceY                The Y coordinate of the source for BltOperation
    @param  DestinationX           The X coordinate of the destination for
                                   BltOperation
    @param  DestinationY           The Y coordinate of the destination for
                                   BltOperation
    @param  Width                  The width of a rectangle in the blt rectangle in
                                   pixels
    @param  Height                 The height of a rectangle in the blt rectangle in
                                   pixels
    @param  Delta                  Not used for EfiBltVideoFill and
                                   EfiBltVideoToVideo operation. If a Delta of 0 is
                                   used, the entire BltBuffer will be operated on. If
                                   a subrectangle of the BltBuffer is used, then
                                   Delta represents the number of bytes in a row of
                                   the BltBuffer.
  
    @retval EFI_INVALID_PARAMETER  Invalid parameter passed in
    @retval EFI_SUCCESS            Blt operation success
  
  **/
  EFI_STATUS
  EFIAPI
  BiosVideoGraphicsOutputVbeBlt (
    IN  EFI_GRAPHICS_OUTPUT_PROTOCOL       *This,
    IN  EFI_GRAPHICS_OUTPUT_BLT_PIXEL      *BltBuffer, OPTIONAL
    IN  EFI_GRAPHICS_OUTPUT_BLT_OPERATION  BltOperation,
    IN  UINTN                              SourceX,
    IN  UINTN                              SourceY,
    IN  UINTN                              DestinationX,
    IN  UINTN                              DestinationY,
    IN  UINTN                              Width,
    IN  UINTN                              Height,
    IN  UINTN                              Delta
    )
  {
    BIOS_VIDEO_DEV                 *BiosVideoPrivate;
    BIOS_VIDEO_MODE_DATA           *Mode;
    EFI_STATUS                      Status;
    UINTN                           DataSize;
  
    if (This == NULL) {
      return EFI_INVALID_PARAMETER;
    }
  
    DataSize = 0;
    if (gBiosVideoBlockSwitchMode) {
      Status = gRT->GetVariable (L"BiosVideoBlockSwitchMode", &gEfiGlobalVariableGuid, NULL, &DataSize, NULL);
      //DBG("BiosVideoGraphicsOutputSetMode: GetVariable BiosVideoBlockSwitchMode: %r\n", Status);
      if (Status == EFI_BUFFER_TOO_SMALL) {
        // var exists - just exit
        //DBG("VbeBlt - block\n");
        return EFI_SUCCESS;
      }
      // var is cleared by Clover - clear our flag to avoid calling of
      // gRT->GetVariable() all the time
      gBiosVideoBlockSwitchMode = FALSE;
    }
    
    BiosVideoPrivate  = BIOS_VIDEO_DEV_FROM_GRAPHICS_OUTPUT_THIS (This);
    Mode              = &BiosVideoPrivate->ModeData[This->Mode->Mode];
  
    return BiosVideoVbeBltWorker (
             BiosVideoPrivate,
             BltBuffer,
             BltOperation,
             SourceX,
             SourceY,
             DestinationX,
             DestinationY,
             Width,
             Height,
             Delta,
             Mode
             );
  }
  
  /**
    Write graphics controller registers.
  
    @param  PciIo                  Pointer to PciIo protocol instance of the
                                   controller
    @param  Address                Register address
    @param  Data                   Data to be written to register
  
    @return None
  
  **/
  VOID
  WriteGraphicsController (
    IN  EFI_PCI_IO_PROTOCOL  *PciIo,
    IN  UINTN                Address,
    IN  UINTN                Data
    )
  {
    Address = Address | (Data << 8);
    PciIo->Io.Write (
                PciIo,
                EfiPciIoWidthUint16,
                EFI_PCI_IO_PASS_THROUGH_BAR,
                VGA_GRAPHICS_CONTROLLER_ADDRESS_REGISTER,
                1,
                &Address
                );
  }
  
  
  /**
    Read the four bit plane of VGA frame buffer.
  
    @param  PciIo                  Pointer to PciIo protocol instance of the
                                   controller
    @param  HardwareBuffer         Hardware VGA frame buffer address
    @param  MemoryBuffer           Memory buffer address
    @param  WidthInBytes           Number of bytes in a line to read
    @param  Height                 Height of the area to read
  
    @return None
  
  **/
  VOID
  VgaReadBitPlanes (
    EFI_PCI_IO_PROTOCOL  *PciIo,
    UINT8                *HardwareBuffer,
    UINT8                *MemoryBuffer,
    UINTN                WidthInBytes,
    UINTN                Height
    )
  {
    UINTN BitPlane;
    UINTN Rows;
    UINTN FrameBufferOffset;
    UINT8 *Source;
    UINT8 *Destination;
  
    //
    // Program the Mode Register Write mode 0, Read mode 0
    //
    WriteGraphicsController (
      PciIo,
      VGA_GRAPHICS_CONTROLLER_MODE_REGISTER,
      VGA_GRAPHICS_CONTROLLER_READ_MODE_0 | VGA_GRAPHICS_CONTROLLER_WRITE_MODE_0
      );
  
    for (BitPlane = 0, FrameBufferOffset = 0;
         BitPlane < VGA_NUMBER_OF_BIT_PLANES;
         BitPlane++, FrameBufferOffset += VGA_BYTES_PER_BIT_PLANE
        ) {
      //
      // Program the Read Map Select Register to select the correct bit plane
      //
      WriteGraphicsController (
        PciIo,
        VGA_GRAPHICS_CONTROLLER_READ_MAP_SELECT_REGISTER,
        BitPlane
        );
  
      Source      = HardwareBuffer;
      Destination = MemoryBuffer + FrameBufferOffset;
  
      for (Rows = 0; Rows < Height; Rows++, Source += VGA_BYTES_PER_SCAN_LINE, Destination += VGA_BYTES_PER_SCAN_LINE) {
        PciIo->Mem.Read (
                    PciIo,
                    EfiPciIoWidthUint8,
                    EFI_PCI_IO_PASS_THROUGH_BAR,
                    (UINT64) (UINTN) Source,
                    WidthInBytes,
                    (VOID *) Destination
                    );
      }
    }
  }
  
  
  /**
    Internal routine to convert VGA color to Grahpics Output color.
  
    @param  MemoryBuffer           Buffer containing VGA color
    @param  CoordinateX            The X coordinate of pixel on screen
    @param  CoordinateY            The Y coordinate of pixel on screen
    @param  BltBuffer              Buffer to contain converted Grahpics Output color
  
    @return None
  
  **/
  VOID
  VgaConvertToGraphicsOutputColor (
    UINT8                          *MemoryBuffer,
    UINTN                          CoordinateX,
    UINTN                          CoordinateY,
    EFI_GRAPHICS_OUTPUT_BLT_PIXEL  *BltBuffer
    )
  {
    UINTN Mask;
    UINTN Bit;
    UINTN Color;
  
    MemoryBuffer += ((CoordinateY << 6) + (CoordinateY << 4) + (CoordinateX >> 3));
    Mask = mVgaBitMaskTable[CoordinateX & 0x07];
    for (Bit = 0x01, Color = 0; Bit < 0x10; Bit <<= 1, MemoryBuffer += VGA_BYTES_PER_BIT_PLANE) {
      if ((*MemoryBuffer & Mask) != 0) {
        Color |= Bit;
      }
    }
  
    *BltBuffer = mVgaColorToGraphicsOutputColor[Color];
  }
  
  /**
    Internal routine to convert Grahpics Output color to VGA color.
  
    @param  BltBuffer              buffer containing Grahpics Output color
  
    @return Converted VGA color
  
  **/
  UINT8
  VgaConvertColor (
    IN  EFI_GRAPHICS_OUTPUT_BLT_PIXEL          *BltBuffer
    )
  {
    UINT8 Color;
  
    Color = (UINT8) ((BltBuffer->Blue >> 7) | ((BltBuffer->Green >> 6) & 0x02) | ((BltBuffer->Red >> 5) & 0x04));
    if ((BltBuffer->Red + BltBuffer->Green + BltBuffer->Blue) > 0x180) {
      Color |= 0x08;
    }
  
    return Color;
  }
  
  
  /**
    Grahpics Output protocol instance to block transfer for VGA device.
  
    @param  This                   Pointer to Grahpics Output protocol instance
    @param  BltBuffer              The data to transfer to screen
    @param  BltOperation           The operation to perform
    @param  SourceX                The X coordinate of the source for BltOperation
    @param  SourceY                The Y coordinate of the source for BltOperation
    @param  DestinationX           The X coordinate of the destination for
                                   BltOperation
    @param  DestinationY           The Y coordinate of the destination for
                                   BltOperation
    @param  Width                  The width of a rectangle in the blt rectangle in
                                   pixels
    @param  Height                 The height of a rectangle in the blt rectangle in
                                   pixels
    @param  Delta                  Not used for EfiBltVideoFill and
                                   EfiBltVideoToVideo operation. If a Delta of 0 is
                                   used, the entire BltBuffer will be operated on. If
                                   a subrectangle of the BltBuffer is used, then
                                   Delta represents the number of bytes in a row of
                                   the BltBuffer.
  
    @retval EFI_INVALID_PARAMETER  Invalid parameter passed in
    @retval EFI_SUCCESS            Blt operation success
  
  **/
  EFI_STATUS
  EFIAPI
  BiosVideoGraphicsOutputVgaBlt (
    IN  EFI_GRAPHICS_OUTPUT_PROTOCOL       *This,
    IN  EFI_GRAPHICS_OUTPUT_BLT_PIXEL      *BltBuffer, OPTIONAL
    IN  EFI_GRAPHICS_OUTPUT_BLT_OPERATION  BltOperation,
    IN  UINTN                              SourceX,
    IN  UINTN                              SourceY,
    IN  UINTN                              DestinationX,
    IN  UINTN                              DestinationY,
    IN  UINTN                              Width,
    IN  UINTN                              Height,
    IN  UINTN                              Delta
    )
  {
    BIOS_VIDEO_DEV      *BiosVideoPrivate;
    EFI_TPL             OriginalTPL;
    UINT8               *MemAddress;
    UINTN               BytesPerScanLine;
    UINTN               Bit;
    UINTN               Index;
    UINTN               Index1;
    UINTN               StartAddress;
    UINTN               Bytes;
    UINTN               Offset;
    UINT8               LeftMask;
    UINT8               RightMask;
    UINTN               Address;
    UINTN               AddressFix;
    UINT8               *Address1;
    UINT8               *SourceAddress;
    UINT8               *DestinationAddress;
    EFI_PCI_IO_PROTOCOL *PciIo;
    UINT8               Data;
    UINT8               PixelColor;
    UINT8               *VgaFrameBuffer;
    UINTN               SourceOffset;
    UINTN               SourceWidth;
    UINTN               Rows;
    UINTN               Columns;
    UINTN               CoordinateX;
    UINTN               CoordinateY;
    UINTN               CurrentMode;
  
    if (This == NULL || ((UINTN) BltOperation) >= EfiGraphicsOutputBltOperationMax) {
      return EFI_INVALID_PARAMETER;
    }
  
    BiosVideoPrivate  = BIOS_VIDEO_DEV_FROM_GRAPHICS_OUTPUT_THIS (This);
  
    CurrentMode = This->Mode->Mode;
    PciIo             = BiosVideoPrivate->PciIo;
    MemAddress        = BiosVideoPrivate->ModeData[CurrentMode].LinearFrameBuffer;
    BytesPerScanLine  = BiosVideoPrivate->ModeData[CurrentMode].BytesPerScanLine >> 3;
    VgaFrameBuffer    = BiosVideoPrivate->VgaFrameBuffer;
  
  
    if (Width == 0 || Height == 0) {
      return EFI_INVALID_PARAMETER;
    }
    //
    // We need to fill the Virtual Screen buffer with the blt data.
    // The virtual screen is upside down, as the first row is the bootom row of
    // the image.
    //
    if (BltOperation == EfiBltVideoToBltBuffer) {
      //
      // Video to BltBuffer: Source is Video, destination is BltBuffer
      //
      if (SourceY + Height > BiosVideoPrivate->ModeData[CurrentMode].VerticalResolution) {
        return EFI_INVALID_PARAMETER;
      }
  
      if (SourceX + Width > BiosVideoPrivate->ModeData[CurrentMode].HorizontalResolution) {
        return EFI_INVALID_PARAMETER;
      }
    } else {
      //
      // BltBuffer to Video: Source is BltBuffer, destination is Video
      //
      if (DestinationY + Height > BiosVideoPrivate->ModeData[CurrentMode].VerticalResolution) {
        return EFI_INVALID_PARAMETER;
      }
  
      if (DestinationX + Width > BiosVideoPrivate->ModeData[CurrentMode].HorizontalResolution) {
        return EFI_INVALID_PARAMETER;
      }
    }
    //
    // If Delta is zero, then the entire BltBuffer is being used, so Delta
    // is the number of bytes in each row of BltBuffer.  Since BltBuffer is Width pixels size,
    // the number of bytes in each row can be computed.
    //
    if (Delta == 0) {
      Delta = Width * sizeof (EFI_GRAPHICS_OUTPUT_BLT_PIXEL);
    }
    //
    // We have to raise to TPL Notify, so we make an atomic write the frame buffer.
    // We would not want a timer based event (Cursor, ...) to come in while we are
    // doing this operation.
    //
    OriginalTPL = gBS->RaiseTPL (TPL_NOTIFY);
  
    //
    // Compute some values we need for VGA
    //
    switch (BltOperation) {
    case EfiBltVideoToBltBuffer:
  
      SourceOffset  = (SourceY << 6) + (SourceY << 4) + (SourceX >> 3);
      SourceWidth   = ((SourceX + Width - 1) >> 3) - (SourceX >> 3) + 1;
  
      //
      // Read all the pixels in the 4 bit planes into a memory buffer that looks like the VGA buffer
      //
      VgaReadBitPlanes (
        PciIo,
        MemAddress + SourceOffset,
        VgaFrameBuffer + SourceOffset,
        SourceWidth,
        Height
        );
  
      //
      // Convert VGA Bit Planes to a Graphics Output 32-bit color value
      //
      BltBuffer += (DestinationY * (Delta >> 2) + DestinationX);
      for (Rows = 0, CoordinateY = SourceY; Rows < Height; Rows++, CoordinateY++, BltBuffer += (Delta >> 2)) {
        for (Columns = 0, CoordinateX = SourceX; Columns < Width; Columns++, CoordinateX++, BltBuffer++) {
          VgaConvertToGraphicsOutputColor (VgaFrameBuffer, CoordinateX, CoordinateY, BltBuffer);
        }
  
        BltBuffer -= Width;
      }
  
      break;
  
    case EfiBltVideoToVideo:
      //
      // Check for an aligned Video to Video operation
      //
      if ((SourceX & 0x07) == 0x00 && (DestinationX & 0x07) == 0x00 && (Width & 0x07) == 0x00) {
        //
        // Program the Mode Register Write mode 1, Read mode 0
        //
        WriteGraphicsController (
          PciIo,
          VGA_GRAPHICS_CONTROLLER_MODE_REGISTER,
          VGA_GRAPHICS_CONTROLLER_READ_MODE_0 | VGA_GRAPHICS_CONTROLLER_WRITE_MODE_1
          );
  
        SourceAddress       = (UINT8 *) (MemAddress + (SourceY << 6) + (SourceY << 4) + (SourceX >> 3));
        DestinationAddress  = (UINT8 *) (MemAddress + (DestinationY << 6) + (DestinationY << 4) + (DestinationX >> 3));
        Bytes               = Width >> 3;
        for (Index = 0, Offset = 0; Index < Height; Index++, Offset += BytesPerScanLine) {
          PciIo->CopyMem (
                  PciIo,
                  EfiPciIoWidthUint8,
                  EFI_PCI_IO_PASS_THROUGH_BAR,
                  (UINT64) (UINTN) (DestinationAddress + Offset),
                  EFI_PCI_IO_PASS_THROUGH_BAR,
                  (UINT64) (UINTN) (SourceAddress + Offset),
                  Bytes
                  );
        }
      } else {
        SourceOffset  = (SourceY << 6) + (SourceY << 4) + (SourceX >> 3);
        SourceWidth   = ((SourceX + Width - 1) >> 3) - (SourceX >> 3) + 1;
  
        //
        // Read all the pixels in the 4 bit planes into a memory buffer that looks like the VGA buffer
        //
        VgaReadBitPlanes (
          PciIo,
          MemAddress + SourceOffset,
          VgaFrameBuffer + SourceOffset,
          SourceWidth,
          Height
          );
      }
  
      break;
  
    case EfiBltVideoFill:
      StartAddress  = (UINTN) (MemAddress + (DestinationY << 6) + (DestinationY << 4) + (DestinationX >> 3));
      Bytes         = ((DestinationX + Width - 1) >> 3) - (DestinationX >> 3);
      LeftMask      = mVgaLeftMaskTable[DestinationX & 0x07];
      RightMask     = mVgaRightMaskTable[(DestinationX + Width - 1) & 0x07];
      if (Bytes == 0) {
        LeftMask = (UINT8) (LeftMask & RightMask);
        RightMask = 0;
      }
  
      if (LeftMask == 0xff) {
        StartAddress--;
        Bytes++;
        LeftMask = 0;
      }
  
      if (RightMask == 0xff) {
        Bytes++;
        RightMask = 0;
      }
  
      PixelColor = VgaConvertColor (BltBuffer);
  
      //
      // Program the Mode Register Write mode 2, Read mode 0
      //
      WriteGraphicsController (
        PciIo,
        VGA_GRAPHICS_CONTROLLER_MODE_REGISTER,
        VGA_GRAPHICS_CONTROLLER_READ_MODE_0 | VGA_GRAPHICS_CONTROLLER_WRITE_MODE_2
        );
  
      //
      // Program the Data Rotate/Function Select Register to replace
      //
      WriteGraphicsController (
        PciIo,
        VGA_GRAPHICS_CONTROLLER_DATA_ROTATE_REGISTER,
        VGA_GRAPHICS_CONTROLLER_FUNCTION_REPLACE
        );
  
      if (LeftMask != 0) {
        //
        // Program the BitMask register with the Left column mask
        //
        WriteGraphicsController (
          PciIo,
          VGA_GRAPHICS_CONTROLLER_BIT_MASK_REGISTER,
          LeftMask
          );
  
        for (Index = 0, Address = StartAddress; Index < Height; Index++, Address += BytesPerScanLine) {
          //
          // Read data from the bit planes into the latches
          //
          PciIo->Mem.Read (
                      PciIo,
                      EfiPciIoWidthUint8,
                      EFI_PCI_IO_PASS_THROUGH_BAR,
                      (UINT64) (UINTN) Address,
                      1,
                      &Data
                      );
          //
          // Write the lower 4 bits of PixelColor to the bit planes in the pixels enabled by BitMask
          //
          PciIo->Mem.Write (
                      PciIo,
                      EfiPciIoWidthUint8,
                      EFI_PCI_IO_PASS_THROUGH_BAR,
                      (UINT64) (UINTN) Address,
                      1,
                      &PixelColor
                      );
        }
      }
  
      if (Bytes > 1) {
        //
        // Program the BitMask register with the middle column mask of 0xff
        //
        WriteGraphicsController (
          PciIo,
          VGA_GRAPHICS_CONTROLLER_BIT_MASK_REGISTER,
          0xff
          );
  
        for (Index = 0, Address = StartAddress + 1; Index < Height; Index++, Address += BytesPerScanLine) {
          PciIo->Mem.Write (
                      PciIo,
                      EfiPciIoWidthFillUint8,
                      EFI_PCI_IO_PASS_THROUGH_BAR,
                      (UINT64) (UINTN) Address,
                      Bytes - 1,
                      &PixelColor
                      );
        }
      }
  
      if (RightMask != 0) {
        //
        // Program the BitMask register with the Right column mask
        //
        WriteGraphicsController (
          PciIo,
          VGA_GRAPHICS_CONTROLLER_BIT_MASK_REGISTER,
          RightMask
          );
  
        for (Index = 0, Address = StartAddress + Bytes; Index < Height; Index++, Address += BytesPerScanLine) {
          //
          // Read data from the bit planes into the latches
          //
          PciIo->Mem.Read (
                      PciIo,
                      EfiPciIoWidthUint8,
                      EFI_PCI_IO_PASS_THROUGH_BAR,
                      (UINT64) (UINTN) Address,
                      1,
                      &Data
                      );
          //
          // Write the lower 4 bits of PixelColor to the bit planes in the pixels enabled by BitMask
          //
          PciIo->Mem.Write (
                      PciIo,
                      EfiPciIoWidthUint8,
                      EFI_PCI_IO_PASS_THROUGH_BAR,
                      (UINT64) (UINTN) Address,
                      1,
                      &PixelColor
                      );
        }
      }
      break;
  
    case EfiBltBufferToVideo:
      StartAddress  = (UINTN) (MemAddress + (DestinationY << 6) + (DestinationY << 4) + (DestinationX >> 3));
      LeftMask      = mVgaBitMaskTable[DestinationX & 0x07];
  
      //
      // Program the Mode Register Write mode 2, Read mode 0
      //
      WriteGraphicsController (
        PciIo,
        VGA_GRAPHICS_CONTROLLER_MODE_REGISTER,
        VGA_GRAPHICS_CONTROLLER_READ_MODE_0 | VGA_GRAPHICS_CONTROLLER_WRITE_MODE_2
        );
  
      //
      // Program the Data Rotate/Function Select Register to replace
      //
      WriteGraphicsController (
        PciIo,
        VGA_GRAPHICS_CONTROLLER_DATA_ROTATE_REGISTER,
        VGA_GRAPHICS_CONTROLLER_FUNCTION_REPLACE
        );
  
      for (Index = 0, Address = StartAddress; Index < Height; Index++, Address += BytesPerScanLine) {
        for (Index1 = 0; Index1 < Width; Index1++) {
          BiosVideoPrivate->LineBuffer[Index1] = VgaConvertColor (&BltBuffer[(SourceY + Index) * (Delta >> 2) + SourceX + Index1]);
        }
        AddressFix = Address;
  
        for (Bit = 0; Bit < 8; Bit++) {
          //
          // Program the BitMask register with the Left column mask
          //
          WriteGraphicsController (
            PciIo,
            VGA_GRAPHICS_CONTROLLER_BIT_MASK_REGISTER,
            LeftMask
            );
  
          for (Index1 = Bit, Address1 = (UINT8 *) AddressFix; Index1 < Width; Index1 += 8, Address1++) {
            //
            // Read data from the bit planes into the latches
            //
            PciIo->Mem.Read (
                        PciIo,
                        EfiPciIoWidthUint8,
                        EFI_PCI_IO_PASS_THROUGH_BAR,
                        (UINT64) (UINTN) Address1,
                        1,
                        &Data
                        );
  
            PciIo->Mem.Write (
                        PciIo,
                        EfiPciIoWidthUint8,
                        EFI_PCI_IO_PASS_THROUGH_BAR,
                        (UINT64) (UINTN) Address1,
                        1,
                        &BiosVideoPrivate->LineBuffer[Index1]
                        );
          }
  
          LeftMask = (UINT8) (LeftMask >> 1);
          if (LeftMask == 0) {
            LeftMask = 0x80;
            AddressFix++;
          }
        }
      }
  
      break;
  
      default: ;
    }
  
    gBS->RestoreTPL (OriginalTPL);
  
    return EFI_SUCCESS;
  }
  
  //
  // VGA Mini Port Protocol Functions
  //
  
  /**
    VgaMiniPort protocol interface to set mode.
  
    @param  This                   Pointer to VgaMiniPort protocol instance
    @param  ModeNumber             The index of the mode
  
    @retval EFI_UNSUPPORTED        The requested mode is not supported
    @retval EFI_SUCCESS            The requested mode is set successfully
  
  **/
  EFI_STATUS
  EFIAPI
  BiosVideoVgaMiniPortSetMode (
    IN  EFI_VGA_MINI_PORT_PROTOCOL  *This,
    IN  UINTN                       ModeNumber
    )
  {
    BIOS_VIDEO_DEV        *BiosVideoPrivate;
    EFI_IA32_REGISTER_SET Regs;
  
    if (This == NULL) {
      return EFI_INVALID_PARAMETER;
    }
  
    //
    // Make sure the ModeNumber is a valid value
    //
    if (ModeNumber >= This->MaxMode) {
      return EFI_UNSUPPORTED;
    }
    //
    // Get the device structure for this device
    //
    BiosVideoPrivate = BIOS_VIDEO_DEV_FROM_VGA_MINI_PORT_THIS (This);
  
    switch (ModeNumber) {
    case 0:
      //
      // Set the 80x25 Text VGA Mode
      //
      Regs.H.AH = 0x00;
      Regs.H.AL = 0x83;
      BiosVideoPrivate->LegacyBios->Int86 (BiosVideoPrivate->LegacyBios, 0x10, &Regs);
  
      Regs.H.AH = 0x11;
      Regs.H.AL = 0x14;
      Regs.H.BL = 0;
      BiosVideoPrivate->LegacyBios->Int86 (BiosVideoPrivate->LegacyBios, 0x10, &Regs);
      break;
  
    case 1:
      //
      // Set the 80x50 Text VGA Mode
      //
      Regs.H.AH = 0x00;
      Regs.H.AL = 0x83;
      BiosVideoPrivate->LegacyBios->Int86 (BiosVideoPrivate->LegacyBios, 0x10, &Regs);
      Regs.H.AH = 0x11;
      Regs.H.AL = 0x12;
      Regs.H.BL = 0;
      BiosVideoPrivate->LegacyBios->Int86 (BiosVideoPrivate->LegacyBios, 0x10, &Regs);
      break;
  
    default:
      return EFI_UNSUPPORTED;
    }
  
    return EFI_SUCCESS;
  }
  
  /**
    Event handler for Exit Boot Service.
  
    @param  Event       The event that be siganlled when exiting boot service.
    @param  Context     Pointer to instance of BIOS_VIDEO_DEV.
  
  **/
  VOID
  EFIAPI
  BiosVideoNotifyExitBootServices (
    IN  EFI_EVENT Event,
    IN  VOID      *Context
    )
  {
    BIOS_VIDEO_DEV         *BiosVideoPrivate;
    EFI_IA32_REGISTER_SET  Regs;
  
    BiosVideoPrivate  = (BIOS_VIDEO_DEV *)Context;
  
    //
    // Set the 80x25 Text VGA Mode
    //
    Regs.H.AH = 0x00;
    Regs.H.AL = 0x03;
    BiosVideoPrivate->LegacyBios->Int86 (BiosVideoPrivate->LegacyBios, 0x10, &Regs);
  
    Regs.H.AH = 0x00;
    Regs.H.AL = 0x83;
    BiosVideoPrivate->LegacyBios->Int86 (BiosVideoPrivate->LegacyBios, 0x10, &Regs);
  
    Regs.H.AH = 0x11;
    Regs.H.AL = 0x04;
    Regs.H.BL = 0;
    BiosVideoPrivate->LegacyBios->Int86 (BiosVideoPrivate->LegacyBios, 0x10, &Regs);
  }
  
  /**
    The user Entry Point for module UefiBiosVideo. The user code starts with this function.
  
    @param[in] ImageHandle    The firmware allocated handle for the EFI image.
    @param[in] SystemTable    A pointer to the EFI System Table.
  
    @retval EFI_SUCCESS       The entry point is executed successfully.
    @retval other             Some error occurs when executing this entry point.
  
  **/
  EFI_STATUS
  EFIAPI
  BiosVideoEntryPoint(
    IN EFI_HANDLE           ImageHandle,
    IN EFI_SYSTEM_TABLE     *SystemTable
    )
  {
    EFI_STATUS  Status;
  
    //
    // Install driver model protocol(s).
    //
    Status = EfiLibInstallDriverBindingComponentName2 (
               ImageHandle,
               SystemTable,
               &gBiosVideoDriverBinding,
               ImageHandle,
               &gBiosVideoComponentName,
               &gBiosVideoComponentName2
               );
  //  ASSERT_EFI_ERROR (Status);
    if (EFI_ERROR (Status)) {
      return Status;
    }
  
    //
    // Install Legacy BIOS GUID to mark this driver as a BIOS Thunk Driver
    //
    return gBS->InstallMultipleProtocolInterfaces (
                  &ImageHandle,
                  &gEfiLegacyBiosGuid,
                  NULL,
                  NULL
                  );
  }
  
  