audk/OvmfPkg/QemuVideoDxe/Driver.c

/** @file
  This driver is a sample implementation of the Graphics Output Protocol for
  the QEMU (Cirrus Logic 5446) video controller.

  Copyright (c) 2006 - 2010, Intel Corporation. All rights reserved.<BR>

  This program and the accompanying materials
  are licensed and made available under the terms and conditions of the BSD License
  which accompanies this distribution. The full text of the license may be found at
  http://opensource.org/licenses/bsd-license.php

  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.

**/

#include "Qemu.h"
#include <IndustryStandard/Acpi.h>

EFI_DRIVER_BINDING_PROTOCOL gQemuVideoDriverBinding = {
  QemuVideoControllerDriverSupported,
  QemuVideoControllerDriverStart,
  QemuVideoControllerDriverStop,
  0x10,
  NULL,
  NULL
};

QEMU_VIDEO_CARD gQemuVideoCardList[] = {
    {
        CIRRUS_LOGIC_VENDOR_ID,
        CIRRUS_LOGIC_5430_DEVICE_ID,
        QEMU_VIDEO_CIRRUS_5430,
        L"Cirrus 5430"
    },{
        CIRRUS_LOGIC_VENDOR_ID,
        CIRRUS_LOGIC_5430_ALTERNATE_DEVICE_ID,
        QEMU_VIDEO_CIRRUS_5430,
        L"Cirrus 5430"
    },{
        CIRRUS_LOGIC_VENDOR_ID,
        CIRRUS_LOGIC_5446_DEVICE_ID,
        QEMU_VIDEO_CIRRUS_5446,
        L"Cirrus 5446"
    },{
        0x1234,
        0x1111,
        QEMU_VIDEO_BOCHS_MMIO,
        L"QEMU Standard VGA"
    },{
        0x1b36,
        0x0100,
        QEMU_VIDEO_BOCHS,
        L"QEMU QXL VGA"
    },{
        0 /* end of list */
    }
};

static QEMU_VIDEO_CARD*
QemuVideoDetect(
  IN UINT16 VendorId,
  IN UINT16 DeviceId
  )
{
  UINTN Index = 0;

  while (gQemuVideoCardList[Index].VendorId != 0) {
    if (gQemuVideoCardList[Index].VendorId == VendorId &&
        gQemuVideoCardList[Index].DeviceId == DeviceId) {
      return gQemuVideoCardList + Index;
    }
    Index++;
  }
  return NULL;
}

/**
  Check if this device is supported.

  @param  This                   The driver binding protocol.
  @param  Controller             The controller handle to check.
  @param  RemainingDevicePath    The remaining device path.

  @retval EFI_SUCCESS            The bus supports this controller.
  @retval EFI_UNSUPPORTED        This device isn't supported.

**/
EFI_STATUS
EFIAPI
QemuVideoControllerDriverSupported (
  IN EFI_DRIVER_BINDING_PROTOCOL    *This,
  IN EFI_HANDLE                     Controller,
  IN EFI_DEVICE_PATH_PROTOCOL       *RemainingDevicePath
  )
{
  EFI_STATUS          Status;
  EFI_PCI_IO_PROTOCOL *PciIo;
  PCI_TYPE00          Pci;
  QEMU_VIDEO_CARD     *Card;

  //
  // Open the PCI I/O Protocol
  //
  Status = gBS->OpenProtocol (
                  Controller,
                  &gEfiPciIoProtocolGuid,
                  (VOID **) &PciIo,
                  This->DriverBindingHandle,
                  Controller,
                  EFI_OPEN_PROTOCOL_BY_DRIVER
                  );
  if (EFI_ERROR (Status)) {
    return Status;
  }

  //
  // Read the PCI Configuration Header from the PCI Device
  //
  Status = PciIo->Pci.Read (
                        PciIo,
                        EfiPciIoWidthUint32,
                        0,
                        sizeof (Pci) / sizeof (UINT32),
                        &Pci
                        );
  if (EFI_ERROR (Status)) {
    goto Done;
  }

  Status = EFI_UNSUPPORTED;
  Card = QemuVideoDetect(Pci.Hdr.VendorId, Pci.Hdr.DeviceId);
  if (Card != NULL) {
    DEBUG ((EFI_D_INFO, "QemuVideo: %s detected\n", Card->Name));
    Status = EFI_SUCCESS;
  }

Done:
  //
  // Close the PCI I/O Protocol
  //
  gBS->CloseProtocol (
        Controller,
        &gEfiPciIoProtocolGuid,
        This->DriverBindingHandle,
        Controller
        );

  return Status;
}

/**
  Start to process the controller.

  @param  This                   The USB bus driver binding instance.
  @param  Controller             The controller to check.
  @param  RemainingDevicePath    The remaining device patch.

  @retval EFI_SUCCESS            The controller is controlled by the usb bus.
  @retval EFI_ALREADY_STARTED    The controller is already controlled by the usb
                                 bus.
  @retval EFI_OUT_OF_RESOURCES   Failed to allocate resources.

**/
EFI_STATUS
EFIAPI
QemuVideoControllerDriverStart (
  IN EFI_DRIVER_BINDING_PROTOCOL    *This,
  IN EFI_HANDLE                     Controller,
  IN EFI_DEVICE_PATH_PROTOCOL       *RemainingDevicePath
  )
{
  EFI_TPL                           OldTpl;
  EFI_STATUS                        Status;
  QEMU_VIDEO_PRIVATE_DATA           *Private;
  EFI_DEVICE_PATH_PROTOCOL          *ParentDevicePath;
  ACPI_ADR_DEVICE_PATH              AcpiDeviceNode;
  PCI_TYPE00                        Pci;
  QEMU_VIDEO_CARD                   *Card;
  EFI_PCI_IO_PROTOCOL               *ChildPciIo;

  OldTpl = gBS->RaiseTPL (TPL_CALLBACK);

  //
  // Allocate Private context data for GOP inteface.
  //
  Private = AllocateZeroPool (sizeof (QEMU_VIDEO_PRIVATE_DATA));
  if (Private == NULL) {
    Status = EFI_OUT_OF_RESOURCES;
    goto RestoreTpl;
  }

  //
  // Set up context record
  //
  Private->Signature  = QEMU_VIDEO_PRIVATE_DATA_SIGNATURE;

  //
  // Open PCI I/O Protocol
  //
  Status = gBS->OpenProtocol (
                  Controller,
                  &gEfiPciIoProtocolGuid,
                  (VOID **) &Private->PciIo,
                  This->DriverBindingHandle,
                  Controller,
                  EFI_OPEN_PROTOCOL_BY_DRIVER
                  );
  if (EFI_ERROR (Status)) {
    goto FreePrivate;
  }

  //
  // Read the PCI Configuration Header from the PCI Device
  //
  Status = Private->PciIo->Pci.Read (
                        Private->PciIo,
                        EfiPciIoWidthUint32,
                        0,
                        sizeof (Pci) / sizeof (UINT32),
                        &Pci
                        );
  if (EFI_ERROR (Status)) {
    goto ClosePciIo;
  }

  //
  // Determine card variant.
  //
  Card = QemuVideoDetect(Pci.Hdr.VendorId, Pci.Hdr.DeviceId);
  if (Card == NULL) {
    Status = EFI_DEVICE_ERROR;
    goto ClosePciIo;
  }
  Private->Variant = Card->Variant;

  //
  // Save original PCI attributes
  //
  Status = Private->PciIo->Attributes (
                    Private->PciIo,
                    EfiPciIoAttributeOperationGet,
                    0,
                    &Private->OriginalPciAttributes
                    );

  if (EFI_ERROR (Status)) {
    goto ClosePciIo;
  }

  //
  // Set new PCI attributes
  //
  Status = Private->PciIo->Attributes (
                            Private->PciIo,
                            EfiPciIoAttributeOperationEnable,
                            EFI_PCI_DEVICE_ENABLE | EFI_PCI_IO_ATTRIBUTE_VGA_MEMORY | EFI_PCI_IO_ATTRIBUTE_VGA_IO,
                            NULL
                            );
  if (EFI_ERROR (Status)) {
    goto ClosePciIo;
  }

  //
  // Check whenever the qemu stdvga mmio bar is present (qemu 1.3+).
  //
  if (Private->Variant == QEMU_VIDEO_BOCHS_MMIO) {
    EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR *MmioDesc;

    Status = Private->PciIo->GetBarAttributes (
                        Private->PciIo,
                        PCI_BAR_IDX2,
                        NULL,
                        (VOID**) &MmioDesc
                        );
    if (EFI_ERROR (Status) ||
        MmioDesc->ResType != ACPI_ADDRESS_SPACE_TYPE_MEM) {
      DEBUG ((EFI_D_INFO, "QemuVideo: No mmio bar, fallback to port io\n"));
      Private->Variant = QEMU_VIDEO_BOCHS;
    } else {
      DEBUG ((EFI_D_INFO, "QemuVideo: Using mmio bar @ 0x%lx\n",
              MmioDesc->AddrRangeMin));
    }

    if (!EFI_ERROR (Status)) {
      FreePool (MmioDesc);
    }
  }

  //
  // Check if accessing the bochs interface works.
  //
  if (Private->Variant == QEMU_VIDEO_BOCHS_MMIO ||
      Private->Variant == QEMU_VIDEO_BOCHS) {
    UINT16 BochsId;
    BochsId = BochsRead(Private, VBE_DISPI_INDEX_ID);
    if ((BochsId & 0xFFF0) != VBE_DISPI_ID0) {
      DEBUG ((EFI_D_INFO, "QemuVideo: BochsID mismatch (got 0x%x)\n", BochsId));
      Status = EFI_DEVICE_ERROR;
      goto RestoreAttributes;
    }
  }

  //
  // Get ParentDevicePath
  //
  Status = gBS->HandleProtocol (
                  Controller,
                  &gEfiDevicePathProtocolGuid,
                  (VOID **) &ParentDevicePath
                  );
  if (EFI_ERROR (Status)) {
    goto RestoreAttributes;
  }

  //
  // Set Gop Device Path
  //
  ZeroMem (&AcpiDeviceNode, sizeof (ACPI_ADR_DEVICE_PATH));
  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));

  Private->GopDevicePath = AppendDevicePathNode (
                                      ParentDevicePath,
                                      (EFI_DEVICE_PATH_PROTOCOL *) &AcpiDeviceNode
                                      );
  if (Private->GopDevicePath == NULL) {
    Status = EFI_OUT_OF_RESOURCES;
    goto RestoreAttributes;
  }

  //
  // Create new child handle and install the device path protocol on it.
  //
  Status = gBS->InstallMultipleProtocolInterfaces (
                  &Private->Handle,
                  &gEfiDevicePathProtocolGuid,
                  Private->GopDevicePath,
                  NULL
                  );
  if (EFI_ERROR (Status)) {
    goto FreeGopDevicePath;
  }

  //
  // Construct video mode buffer
  //
  switch (Private->Variant) {
  case QEMU_VIDEO_CIRRUS_5430:
  case QEMU_VIDEO_CIRRUS_5446:
    Status = QemuVideoCirrusModeSetup (Private);
    break;
  case QEMU_VIDEO_BOCHS_MMIO:
  case QEMU_VIDEO_BOCHS:
    Status = QemuVideoBochsModeSetup (Private);
    break;
  default:
    ASSERT (FALSE);
    Status = EFI_DEVICE_ERROR;
    break;
  }
  if (EFI_ERROR (Status)) {
    goto UninstallGopDevicePath;
  }

  //
  // Start the GOP software stack.
  //
  Status = QemuVideoGraphicsOutputConstructor (Private);
  if (EFI_ERROR (Status)) {
    goto FreeModeData;
  }

  Status = gBS->InstallMultipleProtocolInterfaces (
                  &Private->Handle,
                  &gEfiGraphicsOutputProtocolGuid,
                  &Private->GraphicsOutput,
                  NULL
                  );
  if (EFI_ERROR (Status)) {
    goto DestructQemuVideoGraphics;
  }

  //
  // Reference parent handle from child handle.
  //
  Status = gBS->OpenProtocol (
                Controller,
                &gEfiPciIoProtocolGuid,
                (VOID **) &ChildPciIo,
                This->DriverBindingHandle,
                Private->Handle,
                EFI_OPEN_PROTOCOL_BY_CHILD_CONTROLLER
                );
  if (EFI_ERROR (Status)) {
    goto UninstallGop;
  }

  if (Private->Variant == QEMU_VIDEO_BOCHS_MMIO ||
      Private->Variant == QEMU_VIDEO_BOCHS) {
    InstallVbeShim (Card->Name, Private->GraphicsOutput.Mode->FrameBufferBase);
  }

  gBS->RestoreTPL (OldTpl);
  return EFI_SUCCESS;

UninstallGop:
  gBS->UninstallProtocolInterface (Private->Handle,
         &gEfiGraphicsOutputProtocolGuid, &Private->GraphicsOutput);

DestructQemuVideoGraphics:
  QemuVideoGraphicsOutputDestructor (Private);

FreeModeData:
  FreePool (Private->ModeData);

UninstallGopDevicePath:
  gBS->UninstallProtocolInterface (Private->Handle,
         &gEfiDevicePathProtocolGuid, Private->GopDevicePath);

FreeGopDevicePath:
  FreePool (Private->GopDevicePath);

RestoreAttributes:
  Private->PciIo->Attributes (Private->PciIo, EfiPciIoAttributeOperationSet,
                    Private->OriginalPciAttributes, NULL);

ClosePciIo:
  gBS->CloseProtocol (Controller, &gEfiPciIoProtocolGuid,
         This->DriverBindingHandle, Controller);

FreePrivate:
  FreePool (Private);

RestoreTpl:
  gBS->RestoreTPL (OldTpl);

  return Status;
}

/**
  Stop this device

  @param  This                   The USB bus driver binding protocol.
  @param  Controller             The controller to release.
  @param  NumberOfChildren       The number of children of this device that
                                 opened the controller BY_CHILD.
  @param  ChildHandleBuffer      The array of child handle.

  @retval EFI_SUCCESS            The controller or children are stopped.
  @retval EFI_DEVICE_ERROR       Failed to stop the driver.

**/
EFI_STATUS
EFIAPI
QemuVideoControllerDriverStop (
  IN EFI_DRIVER_BINDING_PROTOCOL    *This,
  IN EFI_HANDLE                     Controller,
  IN UINTN                          NumberOfChildren,
  IN EFI_HANDLE                     *ChildHandleBuffer
  )
{
  EFI_GRAPHICS_OUTPUT_PROTOCOL    *GraphicsOutput;

  EFI_STATUS                      Status;
  QEMU_VIDEO_PRIVATE_DATA  *Private;

  if (NumberOfChildren == 0) {
    //
    // Close the PCI I/O Protocol
    //
    gBS->CloseProtocol (
          Controller,
          &gEfiPciIoProtocolGuid,
          This->DriverBindingHandle,
          Controller
          );
    return EFI_SUCCESS;
  }

  //
  // free all resources for whose access we need the child handle, because the
  // child handle is going away
  //
  ASSERT (NumberOfChildren == 1);
  Status = gBS->OpenProtocol (
                  ChildHandleBuffer[0],
                  &gEfiGraphicsOutputProtocolGuid,
                  (VOID **) &GraphicsOutput,
                  This->DriverBindingHandle,
                  Controller,
                  EFI_OPEN_PROTOCOL_GET_PROTOCOL
                  );
  if (EFI_ERROR (Status)) {
    return Status;
  }

  //
  // Get our private context information
  //
  Private = QEMU_VIDEO_PRIVATE_DATA_FROM_GRAPHICS_OUTPUT_THIS (GraphicsOutput);
  ASSERT (Private->Handle == ChildHandleBuffer[0]);

  QemuVideoGraphicsOutputDestructor (Private);
  //
  // Remove the GOP protocol interface from the system
  //
  Status = gBS->UninstallMultipleProtocolInterfaces (
                  Private->Handle,
                  &gEfiGraphicsOutputProtocolGuid,
                  &Private->GraphicsOutput,
                  NULL
                  );

  if (EFI_ERROR (Status)) {
    return Status;
  }

  //
  // Restore original PCI attributes
  //
  Private->PciIo->Attributes (
                  Private->PciIo,
                  EfiPciIoAttributeOperationSet,
                  Private->OriginalPciAttributes,
                  NULL
                  );

  gBS->CloseProtocol (
        Controller,
        &gEfiPciIoProtocolGuid,
        This->DriverBindingHandle,
        Private->Handle
        );

  FreePool (Private->ModeData);
  gBS->UninstallProtocolInterface (Private->Handle,
         &gEfiDevicePathProtocolGuid, Private->GopDevicePath);
  FreePool (Private->GopDevicePath);

  //
  // Free our instance data
  //
  gBS->FreePool (Private);

  return EFI_SUCCESS;
}

/**
  TODO: Add function description

  @param  Private TODO: add argument description
  @param  Address TODO: add argument description
  @param  Data TODO: add argument description

  TODO: add return values

**/
VOID
outb (
  QEMU_VIDEO_PRIVATE_DATA  *Private,
  UINTN                           Address,
  UINT8                           Data
  )
{
  Private->PciIo->Io.Write (
                      Private->PciIo,
                      EfiPciIoWidthUint8,
                      EFI_PCI_IO_PASS_THROUGH_BAR,
                      Address,
                      1,
                      &Data
                      );
}

/**
  TODO: Add function description

  @param  Private TODO: add argument description
  @param  Address TODO: add argument description
  @param  Data TODO: add argument description

  TODO: add return values

**/
VOID
outw (
  QEMU_VIDEO_PRIVATE_DATA  *Private,
  UINTN                           Address,
  UINT16                          Data
  )
{
  Private->PciIo->Io.Write (
                      Private->PciIo,
                      EfiPciIoWidthUint16,
                      EFI_PCI_IO_PASS_THROUGH_BAR,
                      Address,
                      1,
                      &Data
                      );
}

/**
  TODO: Add function description

  @param  Private TODO: add argument description
  @param  Address TODO: add argument description

  TODO: add return values

**/
UINT8
inb (
  QEMU_VIDEO_PRIVATE_DATA  *Private,
  UINTN                           Address
  )
{
  UINT8 Data;

  Private->PciIo->Io.Read (
                      Private->PciIo,
                      EfiPciIoWidthUint8,
                      EFI_PCI_IO_PASS_THROUGH_BAR,
                      Address,
                      1,
                      &Data
                      );
  return Data;
}

/**
  TODO: Add function description

  @param  Private TODO: add argument description
  @param  Address TODO: add argument description

  TODO: add return values

**/
UINT16
inw (
  QEMU_VIDEO_PRIVATE_DATA  *Private,
  UINTN                           Address
  )
{
  UINT16  Data;

  Private->PciIo->Io.Read (
                      Private->PciIo,
                      EfiPciIoWidthUint16,
                      EFI_PCI_IO_PASS_THROUGH_BAR,
                      Address,
                      1,
                      &Data
                      );
  return Data;
}

/**
  TODO: Add function description

  @param  Private TODO: add argument description
  @param  Index TODO: add argument description
  @param  Red TODO: add argument description
  @param  Green TODO: add argument description
  @param  Blue TODO: add argument description

  TODO: add return values

**/
VOID
SetPaletteColor (
  QEMU_VIDEO_PRIVATE_DATA  *Private,
  UINTN                           Index,
  UINT8                           Red,
  UINT8                           Green,
  UINT8                           Blue
  )
{
  VgaOutb (Private, PALETTE_INDEX_REGISTER, (UINT8) Index);
  VgaOutb (Private, PALETTE_DATA_REGISTER, (UINT8) (Red >> 2));
  VgaOutb (Private, PALETTE_DATA_REGISTER, (UINT8) (Green >> 2));
  VgaOutb (Private, PALETTE_DATA_REGISTER, (UINT8) (Blue >> 2));
}

/**
  TODO: Add function description

  @param  Private TODO: add argument description

  TODO: add return values

**/
VOID
SetDefaultPalette (
  QEMU_VIDEO_PRIVATE_DATA  *Private
  )
{
  UINTN Index;
  UINTN RedIndex;
  UINTN GreenIndex;
  UINTN BlueIndex;

  Index = 0;
  for (RedIndex = 0; RedIndex < 8; RedIndex++) {
    for (GreenIndex = 0; GreenIndex < 8; GreenIndex++) {
      for (BlueIndex = 0; BlueIndex < 4; BlueIndex++) {
        SetPaletteColor (Private, Index, (UINT8) (RedIndex << 5), (UINT8) (GreenIndex << 5), (UINT8) (BlueIndex << 6));
        Index++;
      }
    }
  }
}

/**
  TODO: Add function description

  @param  Private TODO: add argument description

  TODO: add return values

**/
VOID
ClearScreen (
  QEMU_VIDEO_PRIVATE_DATA  *Private
  )
{
  UINT32  Color;

  Color = 0;
  Private->PciIo->Mem.Write (
                        Private->PciIo,
                        EfiPciIoWidthFillUint32,
                        0,
                        0,
                        0x400000 >> 2,
                        &Color
                        );
}

/**
  TODO: Add function description

  @param  Private TODO: add argument description

  TODO: add return values

**/
VOID
DrawLogo (
  QEMU_VIDEO_PRIVATE_DATA  *Private,
  UINTN                           ScreenWidth,
  UINTN                           ScreenHeight
  )
{
}

/**
  TODO: Add function description

  @param  Private TODO: add argument description
  @param  ModeData TODO: add argument description

  TODO: add return values

**/
VOID
InitializeCirrusGraphicsMode (
  QEMU_VIDEO_PRIVATE_DATA  *Private,
  QEMU_VIDEO_CIRRUS_MODES  *ModeData
  )
{
  UINT8 Byte;
  UINTN Index;

  outw (Private, SEQ_ADDRESS_REGISTER, 0x1206);
  outw (Private, SEQ_ADDRESS_REGISTER, 0x0012);

  for (Index = 0; Index < 15; Index++) {
    outw (Private, SEQ_ADDRESS_REGISTER, ModeData->SeqSettings[Index]);
  }

  if (Private->Variant == QEMU_VIDEO_CIRRUS_5430) {
    outb (Private, SEQ_ADDRESS_REGISTER, 0x0f);
    Byte = (UINT8) ((inb (Private, SEQ_DATA_REGISTER) & 0xc7) ^ 0x30);
    outb (Private, SEQ_DATA_REGISTER, Byte);
  }

  outb (Private, MISC_OUTPUT_REGISTER, ModeData->MiscSetting);
  outw (Private, GRAPH_ADDRESS_REGISTER, 0x0506);
  outw (Private, SEQ_ADDRESS_REGISTER, 0x0300);
  outw (Private, CRTC_ADDRESS_REGISTER, 0x2011);

  for (Index = 0; Index < 28; Index++) {
    outw (Private, CRTC_ADDRESS_REGISTER, (UINT16) ((ModeData->CrtcSettings[Index] << 8) | Index));
  }

  for (Index = 0; Index < 9; Index++) {
    outw (Private, GRAPH_ADDRESS_REGISTER, (UINT16) ((GraphicsController[Index] << 8) | Index));
  }

  inb (Private, INPUT_STATUS_1_REGISTER);

  for (Index = 0; Index < 21; Index++) {
    outb (Private, ATT_ADDRESS_REGISTER, (UINT8) Index);
    outb (Private, ATT_ADDRESS_REGISTER, AttributeController[Index]);
  }

  outb (Private, ATT_ADDRESS_REGISTER, 0x20);

  outw (Private, GRAPH_ADDRESS_REGISTER, 0x0009);
  outw (Private, GRAPH_ADDRESS_REGISTER, 0x000a);
  outw (Private, GRAPH_ADDRESS_REGISTER, 0x000b);
  outb (Private, DAC_PIXEL_MASK_REGISTER, 0xff);

  SetDefaultPalette (Private);
  ClearScreen (Private);
}

VOID
BochsWrite (
  QEMU_VIDEO_PRIVATE_DATA  *Private,
  UINT16                   Reg,
  UINT16                   Data
  )
{
  EFI_STATUS   Status;

  if (Private->Variant == QEMU_VIDEO_BOCHS_MMIO) {
    Status = Private->PciIo->Mem.Write (
        Private->PciIo,
        EfiPciIoWidthUint16,
        PCI_BAR_IDX2,
        0x500 + (Reg << 1),
        1,
        &Data
        );
    ASSERT_EFI_ERROR (Status);
  } else {
    outw (Private, VBE_DISPI_IOPORT_INDEX, Reg);
    outw (Private, VBE_DISPI_IOPORT_DATA,  Data);
  }
}

UINT16
BochsRead (
  QEMU_VIDEO_PRIVATE_DATA  *Private,
  UINT16                   Reg
  )
{
  EFI_STATUS   Status;
  UINT16       Data;

  if (Private->Variant == QEMU_VIDEO_BOCHS_MMIO) {
    Status = Private->PciIo->Mem.Read (
        Private->PciIo,
        EfiPciIoWidthUint16,
        PCI_BAR_IDX2,
        0x500 + (Reg << 1),
        1,
        &Data
        );
    ASSERT_EFI_ERROR (Status);
  } else {
    outw (Private, VBE_DISPI_IOPORT_INDEX, Reg);
    Data = inw (Private, VBE_DISPI_IOPORT_DATA);
  }
  return Data;
}

VOID
VgaOutb (
  QEMU_VIDEO_PRIVATE_DATA  *Private,
  UINTN                    Reg,
  UINT8                    Data
  )
{
  EFI_STATUS   Status;

  if (Private->Variant == QEMU_VIDEO_BOCHS_MMIO) {
    Status = Private->PciIo->Mem.Write (
        Private->PciIo,
        EfiPciIoWidthUint8,
        PCI_BAR_IDX2,
        0x400 - 0x3c0 + Reg,
        1,
        &Data
        );
    ASSERT_EFI_ERROR (Status);
  } else {
    outb (Private, Reg, Data);
  }
}

VOID
InitializeBochsGraphicsMode (
  QEMU_VIDEO_PRIVATE_DATA  *Private,
  QEMU_VIDEO_BOCHS_MODES  *ModeData
  )
{
  DEBUG ((EFI_D_INFO, "InitializeBochsGraphicsMode: %dx%d @ %d\n",
          ModeData->Width, ModeData->Height, ModeData->ColorDepth));

  /* unblank */
  VgaOutb (Private, ATT_ADDRESS_REGISTER, 0x20);

  BochsWrite (Private, VBE_DISPI_INDEX_ENABLE,      0);
  BochsWrite (Private, VBE_DISPI_INDEX_BANK,        0);
  BochsWrite (Private, VBE_DISPI_INDEX_X_OFFSET,    0);
  BochsWrite (Private, VBE_DISPI_INDEX_Y_OFFSET,    0);

  BochsWrite (Private, VBE_DISPI_INDEX_BPP,         (UINT16) ModeData->ColorDepth);
  BochsWrite (Private, VBE_DISPI_INDEX_XRES,        (UINT16) ModeData->Width);
  BochsWrite (Private, VBE_DISPI_INDEX_VIRT_WIDTH,  (UINT16) ModeData->Width);
  BochsWrite (Private, VBE_DISPI_INDEX_YRES,        (UINT16) ModeData->Height);
  BochsWrite (Private, VBE_DISPI_INDEX_VIRT_HEIGHT, (UINT16) ModeData->Height);

  BochsWrite (Private, VBE_DISPI_INDEX_ENABLE,
              VBE_DISPI_ENABLED | VBE_DISPI_LFB_ENABLED);

  SetDefaultPalette (Private);
  ClearScreen (Private);
}

EFI_STATUS
EFIAPI
InitializeQemuVideo (
  IN EFI_HANDLE           ImageHandle,
  IN EFI_SYSTEM_TABLE     *SystemTable
  )
{
  EFI_STATUS              Status;

  Status = EfiLibInstallDriverBindingComponentName2 (
             ImageHandle,
             SystemTable,
             &gQemuVideoDriverBinding,
             ImageHandle,
             &gQemuVideoComponentName,
             &gQemuVideoComponentName2
             );
  ASSERT_EFI_ERROR (Status);

  //
  // Install EFI Driver Supported EFI Version Protocol required for
  // EFI drivers that are on PCI and other plug in cards.
  //
  gQemuVideoDriverSupportedEfiVersion.FirmwareVersion = PcdGet32 (PcdDriverSupportedEfiVersion);
  Status = gBS->InstallMultipleProtocolInterfaces (
                  &ImageHandle,
                  &gEfiDriverSupportedEfiVersionProtocolGuid,
                  &gQemuVideoDriverSupportedEfiVersion,
                  NULL
                  );
  ASSERT_EFI_ERROR (Status);

  return Status;
}