Step to UEFI (262)给 QEMU 的 BIOS 增加 BootMenu快捷键

在实验中,我发现 QEMU 启动的虚拟机并不支持调出 BootMenu,为此研究一下如何修改BIOS 添加这个功能。

前面的实验中,我们在启动项目中插入了自定义的 Application,主要代码在BdsPlatform.c 中。继续查看这个文件,可以看到分配快捷键的代码:

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

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

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

和EmulatorPkg 中的PlatformBdsRegisterStaticBootOptions() 函数进行对比(代码位于 \EmulatorPkg\Library\PlatformBmLib\PlatformBm.c中),可以看到后者注册了多个快捷键对应着不同的功能:

/**
  Register the static boot options.
**/
VOID
PlatformBdsRegisterStaticBootOptions (
  VOID
  )
{
  EFI_GRAPHICS_OUTPUT_BLT_PIXEL  Black;
  EFI_GRAPHICS_OUTPUT_BLT_PIXEL  White;
  EFI_INPUT_KEY                  Enter;
  EFI_INPUT_KEY                  F2;
  EFI_INPUT_KEY                  F7;
  EFI_BOOT_MANAGER_LOAD_OPTION   BootOption;
  UINTN                          OptionNumber;

  Black.Blue = Black.Green = Black.Red = Black.Reserved = 0;
  White.Blue = White.Green = White.Red = White.Reserved = 0xFF;

  //
  // Register ENTER as CONTINUE key
  //
  Enter.ScanCode    = SCAN_NULL;
  Enter.UnicodeChar = CHAR_CARRIAGE_RETURN;
  EfiBootManagerRegisterContinueKeyOption (0, &Enter, NULL);
  //
  // Map F2 to Boot Manager Menu
  //
  F2.ScanCode    = SCAN_F2;
  F2.UnicodeChar = CHAR_NULL;
  EfiBootManagerGetBootManagerMenu (&BootOption);
  EfiBootManagerAddKeyOptionVariable (NULL, (UINT16) BootOption.OptionNumber, 0, &F2, NULL);

  //
  // 3. Boot Device List menu
  //
  F7.ScanCode     = SCAN_F7;
  F7.UnicodeChar  = CHAR_NULL;
  OptionNumber    = GetBootManagerMenuAppOption ();
  EfiBootManagerAddKeyOptionVariable (NULL, (UINT16)OptionNumber, 0, &F7, NULL);

  PrintXY (10, 10, &White, &Black, L"F2    to enter Setup.                              ");
  PrintXY (10, 30, &White, &Black, L"F7    to enter Boot Manager Menu.");
  PrintXY (10, 50, &White, &Black, L"Enter to boot directly.");
}

最终修改\OvmfPkg\Library\PlatformBootManagerLib\BdsPlatform.c 代码如下:

//LABZ_Start
EFI_GUID mBootMenuFile = {
  0xEEC25BDC, 0x67F2, 0x4D95, { 0xB1, 0xD5, 0xF8, 0x1B, 0x20, 0x39, 0xD1, 0x1D }
};


/**
  Check if it's a Device Path pointing to BootManagerMenuApp.

  @param  DevicePath     Input device path.

  @retval TRUE   The device path is BootManagerMenuApp File Device Path.
  @retval FALSE  The device path is NOT BootManagerMenuApp File Device Path.
**/
BOOLEAN
IsBootManagerMenuAppFilePath (
  EFI_DEVICE_PATH_PROTOCOL     *DevicePath
)
{
  EFI_HANDLE                      FvHandle;
  VOID                            *NameGuid;
  EFI_STATUS                      Status;

  Status = gBS->LocateDevicePath (&gEfiFirmwareVolume2ProtocolGuid, &DevicePath, &FvHandle);
  if (!EFI_ERROR (Status)) {
    NameGuid = EfiGetNameGuidFromFwVolDevicePathNode ((CONST MEDIA_FW_VOL_FILEPATH_DEVICE_PATH *) DevicePath);
    if (NameGuid != NULL) {
      return CompareGuid (NameGuid, &mBootMenuFile);
    }
  }

  return FALSE;
}

EFI_DEVICE_PATH *
FvFilePath (
  EFI_GUID                     *FileGuid
  )
{

  EFI_STATUS                         Status;
  EFI_LOADED_IMAGE_PROTOCOL          *LoadedImage;
  MEDIA_FW_VOL_FILEPATH_DEVICE_PATH  FileNode;

  EfiInitializeFwVolDevicepathNode (&FileNode, FileGuid);

  Status = gBS->HandleProtocol (
                  gImageHandle,
                  &gEfiLoadedImageProtocolGuid,
                  (VOID **) &LoadedImage
                  );
  ASSERT_EFI_ERROR (Status);
  return AppendDevicePathNode (
           DevicePathFromHandle (LoadedImage->DeviceHandle),
           (EFI_DEVICE_PATH_PROTOCOL *) &FileNode
           );
}

/**
  Create one boot option for BootManagerMenuApp.

  @param  FileGuid          Input file guid for the BootManagerMenuApp.
  @param  Description       Description of the BootManagerMenuApp boot option.
  @param  Position          Position of the new load option to put in the ****Order variable.
  @param  IsBootCategory    Whether this is a boot category.


  @retval OptionNumber      Return the option number info.

**/
UINTN
RegisterBootManagerMenuAppBootOption (
  EFI_GUID                         *FileGuid,
  CHAR16                           *Description,
  UINTN                            Position,
  BOOLEAN                          IsBootCategory
  )
{
  EFI_STATUS                       Status;
  EFI_BOOT_MANAGER_LOAD_OPTION     NewOption;
  EFI_DEVICE_PATH_PROTOCOL         *DevicePath;
  UINTN                            OptionNumber;

  DevicePath = FvFilePath (FileGuid);
  Status = EfiBootManagerInitializeLoadOption (
             &NewOption,
             LoadOptionNumberUnassigned,
             LoadOptionTypeBoot,
             IsBootCategory ? LOAD_OPTION_ACTIVE : LOAD_OPTION_CATEGORY_APP,
             Description,
             DevicePath,
             NULL,
             0
             );
  ASSERT_EFI_ERROR (Status);
  FreePool (DevicePath);

  Status = EfiBootManagerAddLoadOptionVariable (&NewOption, Position);
  ASSERT_EFI_ERROR (Status);

  OptionNumber = NewOption.OptionNumber;

  EfiBootManagerFreeLoadOption (&NewOption);

  return OptionNumber;
}
/**
  Return the boot option number to the BootManagerMenuApp.

  If not found it in the current boot option, create a new one.

  @retval OptionNumber   Return the boot option number to the BootManagerMenuApp.

**/
UINTN
GetBootManagerMenuAppOption (
  VOID
  )
{
  UINTN                        BootOptionCount;
  EFI_BOOT_MANAGER_LOAD_OPTION *BootOptions;
  UINTN                        Index;
  UINTN                        OptionNumber;

  OptionNumber = 0;

  BootOptions = EfiBootManagerGetLoadOptions (&BootOptionCount, LoadOptionTypeBoot);

  for (Index = 0; Index < BootOptionCount; Index++) {
    if (IsBootManagerMenuAppFilePath (BootOptions[Index].FilePath)) {
      OptionNumber = BootOptions[Index].OptionNumber;
      break;
    }
  }

  EfiBootManagerFreeLoadOptions (BootOptions, BootOptionCount);

  if (Index >= BootOptionCount) {
    //
    // If not found the BootManagerMenuApp, create it.
    //
    OptionNumber = (UINT16) RegisterBootManagerMenuAppBootOption (&mBootMenuFile, L"UEFI BootManagerMenuApp", (UINTN) -1, FALSE);
  }

  return OptionNumber;
}
//LABZ_End
VOID
PlatformRegisterOptionsAndKeys (
  VOID
  )
{
  EFI_STATUS                   Status;
  EFI_INPUT_KEY                Enter;
  EFI_INPUT_KEY                F2;
  EFI_INPUT_KEY                F7;  
  EFI_INPUT_KEY                Esc;
  EFI_BOOT_MANAGER_LOAD_OPTION BootOption;
  UINTN                        OptionNumber;
  //
  // Register ENTER as CONTINUE key
  //
  Enter.ScanCode    = SCAN_NULL;
  Enter.UnicodeChar = CHAR_CARRIAGE_RETURN;
  Status = EfiBootManagerRegisterContinueKeyOption (0, &Enter, NULL);
  ASSERT_EFI_ERROR (Status);

  //
  // Map F2 to Boot Manager Menu
  //
  F2.ScanCode     = SCAN_F2;
  F2.UnicodeChar  = CHAR_NULL;
  Esc.ScanCode    = SCAN_ESC;
  Esc.UnicodeChar = CHAR_NULL;
  Status = EfiBootManagerGetBootManagerMenu (&BootOption);
  ASSERT_EFI_ERROR (Status);
  Status = EfiBootManagerAddKeyOptionVariable (
             NULL, (UINT16) BootOption.OptionNumber, 0, &F2, NULL
             );
  ASSERT (Status == EFI_SUCCESS || Status == EFI_ALREADY_STARTED);
  Status = EfiBootManagerAddKeyOptionVariable (
             NULL, (UINT16) BootOption.OptionNumber, 0, &Esc, NULL
             );
  ASSERT (Status == EFI_SUCCESS || Status == EFI_ALREADY_STARTED);
  
  //LABZ_Start
  //
  // 3. Boot Device List menu
  //
  F7.ScanCode     = SCAN_F7;
  F7.UnicodeChar  = CHAR_NULL;
  OptionNumber    = GetBootManagerMenuAppOption ();
  EfiBootManagerAddKeyOptionVariable (NULL, (UINT16)OptionNumber, 0, &F7, NULL);  
  //LABZ_End
}

此外,在 \OvmfPkg\OvmfPkgX64.dsc 中添加BootManagerMenuApp.inf如下:

    <PcdsFixedAtBuild>
      gEfiMdePkgTokenSpaceGuid.PcdDebugPropertyMask|0xFF
      gEfiShellPkgTokenSpaceGuid.PcdShellLibAutoInitialize|FALSE
      gEfiMdePkgTokenSpaceGuid.PcdUefiLibMaxPrintBufferSize|8000
  }

  MdeModulePkg/Application/BootManagerMenuApp/BootManagerMenuApp.inf

!if $(SECURE_BOOT_ENABLE) == TRUE
  SecurityPkg/VariableAuthenticated/SecureBootConfigDxe/SecureBootConfigDxe.inf
  OvmfPkg/EnrollDefaultKeys/EnrollDefaultKeys.inf
!endif

\OvmfPkg\OvmfPkgX64.fdf修改如下:

!if $(TOOL_CHAIN_TAG) != "XCODE5"
INF  ShellPkg/DynamicCommand/TftpDynamicCommand/TftpDynamicCommand.inf
INF  ShellPkg/DynamicCommand/HttpDynamicCommand/HttpDynamicCommand.inf
INF  OvmfPkg/LinuxInitrdDynamicShellCommand/LinuxInitrdDynamicShellCommand.inf
!endif
INF  ShellPkg/Application/Shell/Shell.inf

INF  MdeModulePkg/Application/BootManagerMenuApp/BootManagerMenuApp.inf

INF MdeModulePkg/Logo/LogoDxe.inf

#
# Network modules
#
!if $(E1000_ENABLE)

可以看到整体和之前的“BootMenu插入自己的Application”并无多大差别,只是多了使用EfiBootManagerAddKeyOptionVariable() 函数将  Application 和快捷键关联起来的。

运行结果:


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