EmbeddedPkg/Drivers/FdtPlatformDxe/ShellSetFdt.c - device/linaro/bootloader/edk2 - Git at Google

 /** @file

   Copyright (c) 2015, ARM Ltd. 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 "FdtPlatform.h"

 STATIC CONST SHELL_PARAM_ITEM ParamList[] = {
   {L"-i", TypeFlag },
   {NULL , TypeMax  }
 };

 /**
   Display FDT device paths.

   Display in text form the device paths used to install the FDT from the
   highest to the lowest priority.

 **/
 STATIC
 VOID
 DisplayFdtDevicePaths (
   VOID
   )
 {
   EFI_STATUS  Status;
   UINTN       DataSize;
   CHAR16      *TextDevicePath;
   CHAR16      *TextDevicePaths;
   CHAR16      *TextDevicePathSeparator;

   ShellPrintHiiEx (
     -1, -1, NULL,
     STRING_TOKEN (STR_SETFDT_DEVICE_PATH_LIST),
     mFdtPlatformDxeHiiHandle
     );

   if (FeaturePcdGet (PcdOverridePlatformFdt)) {
     DataSize = 0;
     Status = gRT->GetVariable (
                     L"Fdt",
                     &gFdtVariableGuid,
                     NULL,
                     &DataSize,
                     NULL
                     );

     //
     // Keep going only if the "Fdt" variable is defined.
     //

     if (Status == EFI_BUFFER_TOO_SMALL) {
       TextDevicePath = AllocatePool (DataSize);
       if (TextDevicePath == NULL) {
         return;
       }

       Status = gRT->GetVariable (
                       L"Fdt",
                       &gFdtVariableGuid,
                       NULL,
                       &DataSize,
                       TextDevicePath
                       );
       if (!EFI_ERROR (Status)) {
         ShellPrintHiiEx (
           -1, -1, NULL,
           STRING_TOKEN (STR_SETFDT_DEVICE_PATH),
           mFdtPlatformDxeHiiHandle,
           TextDevicePath
           );
       }

       FreePool (TextDevicePath);
     }
   }

   //
   // Loop over the device path list provided by "PcdFdtDevicePaths". The device
   // paths are in text form and separated by a semi-colon.
   //

   TextDevicePaths = AllocateCopyPool (
                       StrSize ((CHAR16*)PcdGetPtr (PcdFdtDevicePaths)),
                       (CHAR16*)PcdGetPtr (PcdFdtDevicePaths)
                       );
   if (TextDevicePaths == NULL) {
     return;
   }

   for (TextDevicePath = TextDevicePaths;
        *TextDevicePath != L'\0'        ; ) {
     TextDevicePathSeparator = StrStr (TextDevicePath, L";");

     if (TextDevicePathSeparator != NULL) {
       *TextDevicePathSeparator = L'\0';
     }

     ShellPrintHiiEx (
       -1, -1, NULL,
       STRING_TOKEN (STR_SETFDT_DEVICE_PATH),
       mFdtPlatformDxeHiiHandle,
       TextDevicePath
       );

     if (TextDevicePathSeparator == NULL) {
       break;
     }
     TextDevicePath = TextDevicePathSeparator + 1;
   }

   FreePool (TextDevicePaths);
 }

 /**
   Update the text device path stored in the "Fdt" UEFI variable given
   an EFI Shell file path or a text device path.

   This function is a subroutine of the ShellDynCmdSetFdtHandler() function
   to make its code easier to read.

   @param[in]  Shell          The instance of the shell protocol used in the
                              context of processing the "setfdt" command.
   @param[in]  FilePath       EFI Shell path or the device path to the FDT file.

   @return  SHELL_SUCCESS            The text device path was succesfully updated.
   @return  SHELL_INVALID_PARAMETER  The Shell file path is not valid.
   @return  SHELL_OUT_OF_RESOURCES   A memory allocation failed.
   @return  SHELL_DEVICE_ERROR       The "Fdt" variable could not be saved due to a hardware failure.
   @return  SHELL_ACCESS_DENIED      The "Fdt" variable is read-only.
   @return  SHELL_ACCESS_DENIED      The "Fdt" variable cannot be deleted.
   @return  SHELL_ACCESS_DENIED      The "Fdt" variable could not be written due to security violation.
   @return  SHELL_NOT_FOUND          Device path to text protocol not found.
   @return  SHELL_ABORTED            Operation aborted.

 **/
 STATIC
 SHELL_STATUS
 UpdateFdtTextDevicePath (
   IN EFI_SHELL_PROTOCOL  *Shell,
   IN CONST CHAR16        *FilePath
   )
 {
   EFI_STATUS                          Status;
   EFI_DEVICE_PATH                     *DevicePath;
   EFI_DEVICE_PATH_TO_TEXT_PROTOCOL    *EfiDevicePathToTextProtocol;
   CHAR16                              *TextDevicePath;
   CHAR16                              *FdtVariableValue;
   EFI_DEVICE_PATH_FROM_TEXT_PROTOCOL  *EfiDevicePathFromTextProtocol;
   SHELL_STATUS                        ShellStatus;

   ASSERT (FilePath != NULL);
   DevicePath       = NULL;
   TextDevicePath   = NULL;
   FdtVariableValue = NULL;

   if (*FilePath != L'\0') {
     DevicePath = Shell->GetDevicePathFromFilePath (FilePath);
     if (DevicePath != NULL) {
       Status = gBS->LocateProtocol (
                       &gEfiDevicePathToTextProtocolGuid,
                       NULL,
                       (VOID **)&EfiDevicePathToTextProtocol
                       );
       if (EFI_ERROR (Status)) {
         goto Error;
       }

       TextDevicePath = EfiDevicePathToTextProtocol->ConvertDevicePathToText (
                                                       DevicePath,
                                                       FALSE,
                                                       FALSE
                                                       );
       if (TextDevicePath == NULL) {
         Status = EFI_OUT_OF_RESOURCES;
         goto Error;
       }
       FdtVariableValue = TextDevicePath;
     } else {
       //
       // Try to convert back the EFI Device Path String into a EFI device Path
       // to ensure the format is valid
       //
       Status = gBS->LocateProtocol (
                       &gEfiDevicePathFromTextProtocolGuid,
                       NULL,
                       (VOID **)&EfiDevicePathFromTextProtocol
                       );
       if (EFI_ERROR (Status)) {
         goto Error;
       }

       DevicePath = EfiDevicePathFromTextProtocol->ConvertTextToDevicePath (
                                                     FilePath
                                                     );
       if (DevicePath == NULL) {
         Status = EFI_INVALID_PARAMETER;
         goto Error;
       }
       FdtVariableValue = (CHAR16*)FilePath;
     }
   }

   Status = gRT->SetVariable (
                   (CHAR16*)L"Fdt",
                   &gFdtVariableGuid,
                   EFI_VARIABLE_RUNTIME_ACCESS    |
                   EFI_VARIABLE_NON_VOLATILE      |
                   EFI_VARIABLE_BOOTSERVICE_ACCESS ,
                   (FdtVariableValue != NULL) ?
                   StrSize (FdtVariableValue) : 0,
                   FdtVariableValue
                   );

 Error:
   ShellStatus = EfiCodeToShellCode (Status);
   if (!EFI_ERROR (Status)) {
     if (FdtVariableValue != NULL) {
       ShellPrintHiiEx (
         -1, -1, NULL,
         STRING_TOKEN (STR_SETFDT_UPDATE_SUCCEEDED),
         mFdtPlatformDxeHiiHandle,
         FdtVariableValue
         );
     } else {
       ShellPrintHiiEx (
         -1, -1, NULL,
         STRING_TOKEN (STR_SETFDT_UPDATE_DELETED),
         mFdtPlatformDxeHiiHandle
         );
     }
   } else {
     if (Status == EFI_INVALID_PARAMETER) {
       ShellPrintHiiEx (
         -1, -1, NULL,
         STRING_TOKEN (STR_SETFDT_INVALID_PATH),
         mFdtPlatformDxeHiiHandle,
         FilePath
         );
     } else {
       ShellPrintHiiEx (
         -1, -1, NULL,
         STRING_TOKEN (STR_SETFDT_ERROR),
         mFdtPlatformDxeHiiHandle,
         Status
         );
     }
   }

   if (DevicePath != NULL) {
     FreePool (DevicePath);
   }
   if (TextDevicePath != NULL) {
     FreePool (TextDevicePath);
   }

   return ShellStatus;
 }

 /**
   This is the shell command "setfdt" handler function. This function handles
   the command when it is invoked in the shell.

   @param[in]  This             The instance of the
                                EFI_SHELL_DYNAMIC_COMMAND_PROTOCOL.
   @param[in]  SystemTable      The pointer to the UEFI system table.
   @param[in]  ShellParameters  The parameters associated with the command.
   @param[in]  Shell            The instance of the shell protocol used in the
                                context of processing this command.

   @return  SHELL_SUCCESS            The operation was successful.
   @return  SHELL_ABORTED            Operation aborted due to internal error.
   @return  SHELL_INVALID_PARAMETER  The parameters of the command are not valid.
   @return  SHELL_INVALID_PARAMETER  The EFI Shell file path is not valid.
   @return  SHELL_NOT_FOUND          Failed to locate a protocol or a file.
   @return  SHELL_UNSUPPORTED        Device path not supported.
   @return  SHELL_OUT_OF_RESOURCES   A memory allocation failed.
   @return  SHELL_DEVICE_ERROR       The "Fdt" variable could not be saved due to a hardware failure.
   @return  SHELL_ACCESS_DENIED      The "Fdt" variable is read-only.
   @return  SHELL_ACCESS_DENIED      The "Fdt" variable cannot be deleted.
   @return  SHELL_ACCESS_DENIED      The "Fdt" variable could not be written due to security violation.

 **/
 SHELL_STATUS
 EFIAPI
 ShellDynCmdSetFdtHandler (
   IN EFI_SHELL_DYNAMIC_COMMAND_PROTOCOL  *This,
   IN EFI_SYSTEM_TABLE                    *SystemTable,
   IN EFI_SHELL_PARAMETERS_PROTOCOL       *ShellParameters,
   IN EFI_SHELL_PROTOCOL                  *Shell
   )
 {
   SHELL_STATUS  ShellStatus;
   EFI_STATUS    Status;
   LIST_ENTRY    *ParamPackage;
   BOOLEAN       FilePath;
   CONST CHAR16  *ValueStr;
   CHAR16        *TextDevicePath;

   ShellStatus  = SHELL_SUCCESS;
   ParamPackage = NULL;
   FilePath     = FALSE;

   //
   // Install the Shell and Shell Parameters Protocols on the driver
   // image. This is necessary for the initialisation of the Shell
   // Library to succeed in the next step.
   //
   Status = gBS->InstallMultipleProtocolInterfaces (
                   &gImageHandle,
                   &gEfiShellProtocolGuid, Shell,
                   &gEfiShellParametersProtocolGuid, ShellParameters,
                   NULL
                   );
   if (EFI_ERROR (Status)) {
     return SHELL_ABORTED;
   }

   //
   // Initialise the Shell Library as we are going to use it.
   // Assert that the return code is EFI_SUCCESS as it should.
   // To anticipate any change is the codes returned by
   // ShellInitialize(), leave in case of error.
   //
   Status = ShellInitialize ();
   if (EFI_ERROR (Status)) {
     ASSERT_EFI_ERROR (Status);
     return SHELL_ABORTED;
   }

   Status = ShellCommandLineParse (ParamList, &ParamPackage, NULL, TRUE);
   if (!EFI_ERROR (Status)) {
     switch (ShellCommandLineGetCount (ParamPackage)) {
     case 1:
       //
       // Case "setfdt" or "setfdt -i"
       //
       if (!ShellCommandLineGetFlag (ParamPackage, L"-i")) {
         DisplayFdtDevicePaths ();
       }
       break;

     case 2:
       //
       // Case "setfdt file_path"    or
       //      "setfdt -i file_path" or
       //      "setfdt file_path -i"
       //
       FilePath = TRUE;
       break;

     default:
       Status = EFI_INVALID_PARAMETER;
     }
   }
   if (EFI_ERROR (Status)) {
     ShellStatus = EfiCodeToShellCode (Status);
     ShellPrintHiiEx (
       -1, -1, NULL,
       STRING_TOKEN (STR_SETFDT_ERROR),
       mFdtPlatformDxeHiiHandle,
       Status
       );
     goto Error;
   }

   //
   // Update the preferred device path for the FDT if asked for.
   //
   if (FilePath) {
     ValueStr = ShellCommandLineGetRawValue (ParamPackage, 1);
     ShellPrintHiiEx (
       -1, -1, NULL,
       STRING_TOKEN (STR_SETFDT_UPDATING),
       mFdtPlatformDxeHiiHandle
       );
     ShellStatus = UpdateFdtTextDevicePath (Shell, ValueStr);
     if (ShellStatus != SHELL_SUCCESS) {
       goto Error;
     }
   }

   //
   // Run the FDT installation process if asked for.
   //
   if (ShellCommandLineGetFlag (ParamPackage, L"-i")) {
     ShellPrintHiiEx (
       -1, -1, NULL,
       STRING_TOKEN (STR_SETFDT_INSTALLING),
       mFdtPlatformDxeHiiHandle
       );
     Status = RunFdtInstallation (&TextDevicePath);
     ShellStatus = EfiCodeToShellCode (Status);
     if (!EFI_ERROR (Status)) {
       ShellPrintHiiEx (
         -1, -1, NULL,
         STRING_TOKEN (STR_SETFDT_INSTALL_SUCCEEDED),
         mFdtPlatformDxeHiiHandle,
         TextDevicePath
         );
       FreePool (TextDevicePath);
     } else {
       if (Status == EFI_INVALID_PARAMETER) {
         ShellPrintHiiEx (
           -1, -1, NULL,
           STRING_TOKEN (STR_SETFDT_INVALID_DEVICE_PATH),
           mFdtPlatformDxeHiiHandle
           );
       } else {
         ShellPrintHiiEx (
           -1, -1, NULL,
           STRING_TOKEN (STR_SETFDT_ERROR),
           mFdtPlatformDxeHiiHandle,
           Status
           );
       }
       DisplayFdtDevicePaths ();
     }
   }

 Error:
   gBS->UninstallMultipleProtocolInterfaces (
          gImageHandle,
          &gEfiShellProtocolGuid, Shell,
          &gEfiShellParametersProtocolGuid, ShellParameters,
          NULL
          );
   ShellCommandLineFreeVarList (ParamPackage);

   return ShellStatus;
 }

 /**
   This is the shell command "setfdt" help handler function. This
   function returns the formatted help for the "setfdt" command.
   The format matchs that in Appendix B of the revision 2.1 of the
   UEFI Shell Specification.

   @param[in]  This      The instance of the EFI_SHELL_DYNAMIC_COMMAND_PROTOCOL.
   @param[in]  Language  The pointer to the language string to use.

   @return  CHAR16*  Pool allocated help string, must be freed by caller.
 **/
 CHAR16*
 EFIAPI
 ShellDynCmdSetFdtGetHelp (
   IN EFI_SHELL_DYNAMIC_COMMAND_PROTOCOL  *This,
   IN CONST CHAR8                         *Language
   )
 {
   //
   // This allocates memory. The caller has to free the allocated memory.
   //
   return HiiGetString (
                 mFdtPlatformDxeHiiHandle,
                 STRING_TOKEN (STR_GET_HELP_SETFDT),
                 Language
                 );
 }
	/** @file

	Copyright (c) 2015, ARM Ltd. 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 "FdtPlatform.h"

	STATIC CONST SHELL_PARAM_ITEM ParamList[] = {
	{L"-i", TypeFlag },
	{NULL , TypeMax }
	};

	/**
	Display FDT device paths.

	Display in text form the device paths used to install the FDT from the
	highest to the lowest priority.

	**/
	STATIC
	VOID
	DisplayFdtDevicePaths (
	VOID
	)
	{
	EFI_STATUS Status;
	UINTN DataSize;
	CHAR16 *TextDevicePath;
	CHAR16 *TextDevicePaths;
	CHAR16 *TextDevicePathSeparator;

	ShellPrintHiiEx (
	-1, -1, NULL,
	STRING_TOKEN (STR_SETFDT_DEVICE_PATH_LIST),
	mFdtPlatformDxeHiiHandle
	);

	if (FeaturePcdGet (PcdOverridePlatformFdt)) {
	DataSize = 0;
	Status = gRT->GetVariable (
	L"Fdt",
	&gFdtVariableGuid,
	NULL,
	&DataSize,
	NULL
	);

	//
	// Keep going only if the "Fdt" variable is defined.
	//

	if (Status == EFI_BUFFER_TOO_SMALL) {
	TextDevicePath = AllocatePool (DataSize);
	if (TextDevicePath == NULL) {
	return;
	}

	Status = gRT->GetVariable (
	L"Fdt",
	&gFdtVariableGuid,
	NULL,
	&DataSize,
	TextDevicePath
	);
	if (!EFI_ERROR (Status)) {
	ShellPrintHiiEx (
	-1, -1, NULL,
	STRING_TOKEN (STR_SETFDT_DEVICE_PATH),
	mFdtPlatformDxeHiiHandle,
	TextDevicePath
	);
	}

	FreePool (TextDevicePath);
	}
	}

	//
	// Loop over the device path list provided by "PcdFdtDevicePaths". The device
	// paths are in text form and separated by a semi-colon.
	//

	TextDevicePaths = AllocateCopyPool (
	StrSize ((CHAR16*)PcdGetPtr (PcdFdtDevicePaths)),
	(CHAR16*)PcdGetPtr (PcdFdtDevicePaths)
	);
	if (TextDevicePaths == NULL) {
	return;
	}

	for (TextDevicePath = TextDevicePaths;
	*TextDevicePath != L'\0' ; ) {
	TextDevicePathSeparator = StrStr (TextDevicePath, L";");

	if (TextDevicePathSeparator != NULL) {
	*TextDevicePathSeparator = L'\0';
	}

	ShellPrintHiiEx (
	-1, -1, NULL,
	STRING_TOKEN (STR_SETFDT_DEVICE_PATH),
	mFdtPlatformDxeHiiHandle,
	TextDevicePath
	);

	if (TextDevicePathSeparator == NULL) {
	break;
	}
	TextDevicePath = TextDevicePathSeparator + 1;
	}

	FreePool (TextDevicePaths);
	}

	/**
	Update the text device path stored in the "Fdt" UEFI variable given
	an EFI Shell file path or a text device path.

	This function is a subroutine of the ShellDynCmdSetFdtHandler() function
	to make its code easier to read.

	@param[in] Shell The instance of the shell protocol used in the
	context of processing the "setfdt" command.
	@param[in] FilePath EFI Shell path or the device path to the FDT file.

	@return SHELL_SUCCESS The text device path was succesfully updated.
	@return SHELL_INVALID_PARAMETER The Shell file path is not valid.
	@return SHELL_OUT_OF_RESOURCES A memory allocation failed.
	@return SHELL_DEVICE_ERROR The "Fdt" variable could not be saved due to a hardware failure.
	@return SHELL_ACCESS_DENIED The "Fdt" variable is read-only.
	@return SHELL_ACCESS_DENIED The "Fdt" variable cannot be deleted.
	@return SHELL_ACCESS_DENIED The "Fdt" variable could not be written due to security violation.
	@return SHELL_NOT_FOUND Device path to text protocol not found.
	@return SHELL_ABORTED Operation aborted.

	**/
	STATIC
	SHELL_STATUS
	UpdateFdtTextDevicePath (
	IN EFI_SHELL_PROTOCOL *Shell,
	IN CONST CHAR16 *FilePath
	)
	{
	EFI_STATUS Status;
	EFI_DEVICE_PATH *DevicePath;
	EFI_DEVICE_PATH_TO_TEXT_PROTOCOL *EfiDevicePathToTextProtocol;
	CHAR16 *TextDevicePath;
	CHAR16 *FdtVariableValue;
	EFI_DEVICE_PATH_FROM_TEXT_PROTOCOL *EfiDevicePathFromTextProtocol;
	SHELL_STATUS ShellStatus;

	ASSERT (FilePath != NULL);
	DevicePath = NULL;
	TextDevicePath = NULL;
	FdtVariableValue = NULL;

	if (*FilePath != L'\0') {
	DevicePath = Shell->GetDevicePathFromFilePath (FilePath);
	if (DevicePath != NULL) {
	Status = gBS->LocateProtocol (
	&gEfiDevicePathToTextProtocolGuid,
	NULL,
	(VOID **)&EfiDevicePathToTextProtocol
	);
	if (EFI_ERROR (Status)) {
	goto Error;
	}

	TextDevicePath = EfiDevicePathToTextProtocol->ConvertDevicePathToText (
	DevicePath,
	FALSE,
	FALSE
	);
	if (TextDevicePath == NULL) {
	Status = EFI_OUT_OF_RESOURCES;
	goto Error;
	}
	FdtVariableValue = TextDevicePath;
	} else {
	//
	// Try to convert back the EFI Device Path String into a EFI device Path
	// to ensure the format is valid
	//
	Status = gBS->LocateProtocol (
	&gEfiDevicePathFromTextProtocolGuid,
	NULL,
	(VOID **)&EfiDevicePathFromTextProtocol
	);
	if (EFI_ERROR (Status)) {
	goto Error;
	}

	DevicePath = EfiDevicePathFromTextProtocol->ConvertTextToDevicePath (
	FilePath
	);
	if (DevicePath == NULL) {
	Status = EFI_INVALID_PARAMETER;
	goto Error;
	}
	FdtVariableValue = (CHAR16*)FilePath;
	}
	}

	Status = gRT->SetVariable (
	(CHAR16*)L"Fdt",
	&gFdtVariableGuid,
	EFI_VARIABLE_RUNTIME_ACCESS \|
	EFI_VARIABLE_NON_VOLATILE \|
	EFI_VARIABLE_BOOTSERVICE_ACCESS ,
	(FdtVariableValue != NULL) ?
	StrSize (FdtVariableValue) : 0,
	FdtVariableValue
	);

	Error:
	ShellStatus = EfiCodeToShellCode (Status);
	if (!EFI_ERROR (Status)) {
	if (FdtVariableValue != NULL) {
	ShellPrintHiiEx (
	-1, -1, NULL,
	STRING_TOKEN (STR_SETFDT_UPDATE_SUCCEEDED),
	mFdtPlatformDxeHiiHandle,
	FdtVariableValue
	);
	} else {
	ShellPrintHiiEx (
	-1, -1, NULL,
	STRING_TOKEN (STR_SETFDT_UPDATE_DELETED),
	mFdtPlatformDxeHiiHandle
	);
	}
	} else {
	if (Status == EFI_INVALID_PARAMETER) {
	ShellPrintHiiEx (
	-1, -1, NULL,
	STRING_TOKEN (STR_SETFDT_INVALID_PATH),
	mFdtPlatformDxeHiiHandle,
	FilePath
	);
	} else {
	ShellPrintHiiEx (
	-1, -1, NULL,
	STRING_TOKEN (STR_SETFDT_ERROR),
	mFdtPlatformDxeHiiHandle,
	Status
	);
	}
	}

	if (DevicePath != NULL) {
	FreePool (DevicePath);
	}
	if (TextDevicePath != NULL) {
	FreePool (TextDevicePath);
	}

	return ShellStatus;
	}

	/**
	This is the shell command "setfdt" handler function. This function handles
	the command when it is invoked in the shell.

	@param[in] This The instance of the
	EFI_SHELL_DYNAMIC_COMMAND_PROTOCOL.
	@param[in] SystemTable The pointer to the UEFI system table.
	@param[in] ShellParameters The parameters associated with the command.
	@param[in] Shell The instance of the shell protocol used in the
	context of processing this command.

	@return SHELL_SUCCESS The operation was successful.
	@return SHELL_ABORTED Operation aborted due to internal error.
	@return SHELL_INVALID_PARAMETER The parameters of the command are not valid.
	@return SHELL_INVALID_PARAMETER The EFI Shell file path is not valid.
	@return SHELL_NOT_FOUND Failed to locate a protocol or a file.
	@return SHELL_UNSUPPORTED Device path not supported.
	@return SHELL_OUT_OF_RESOURCES A memory allocation failed.
	@return SHELL_DEVICE_ERROR The "Fdt" variable could not be saved due to a hardware failure.
	@return SHELL_ACCESS_DENIED The "Fdt" variable is read-only.
	@return SHELL_ACCESS_DENIED The "Fdt" variable cannot be deleted.
	@return SHELL_ACCESS_DENIED The "Fdt" variable could not be written due to security violation.

	**/
	SHELL_STATUS
	EFIAPI
	ShellDynCmdSetFdtHandler (
	IN EFI_SHELL_DYNAMIC_COMMAND_PROTOCOL *This,
	IN EFI_SYSTEM_TABLE *SystemTable,
	IN EFI_SHELL_PARAMETERS_PROTOCOL *ShellParameters,
	IN EFI_SHELL_PROTOCOL *Shell
	)
	{
	SHELL_STATUS ShellStatus;
	EFI_STATUS Status;
	LIST_ENTRY *ParamPackage;
	BOOLEAN FilePath;
	CONST CHAR16 *ValueStr;
	CHAR16 *TextDevicePath;

	ShellStatus = SHELL_SUCCESS;
	ParamPackage = NULL;
	FilePath = FALSE;

	//
	// Install the Shell and Shell Parameters Protocols on the driver
	// image. This is necessary for the initialisation of the Shell
	// Library to succeed in the next step.
	//
	Status = gBS->InstallMultipleProtocolInterfaces (
	&gImageHandle,
	&gEfiShellProtocolGuid, Shell,
	&gEfiShellParametersProtocolGuid, ShellParameters,
	NULL
	);
	if (EFI_ERROR (Status)) {
	return SHELL_ABORTED;
	}

	//
	// Initialise the Shell Library as we are going to use it.
	// Assert that the return code is EFI_SUCCESS as it should.
	// To anticipate any change is the codes returned by
	// ShellInitialize(), leave in case of error.
	//
	Status = ShellInitialize ();
	if (EFI_ERROR (Status)) {
	ASSERT_EFI_ERROR (Status);
	return SHELL_ABORTED;
	}

	Status = ShellCommandLineParse (ParamList, &ParamPackage, NULL, TRUE);
	if (!EFI_ERROR (Status)) {
	switch (ShellCommandLineGetCount (ParamPackage)) {
	case 1:
	//
	// Case "setfdt" or "setfdt -i"
	//
	if (!ShellCommandLineGetFlag (ParamPackage, L"-i")) {
	DisplayFdtDevicePaths ();
	}
	break;

	case 2:
	//
	// Case "setfdt file_path" or
	// "setfdt -i file_path" or
	// "setfdt file_path -i"
	//
	FilePath = TRUE;
	break;

	default:
	Status = EFI_INVALID_PARAMETER;
	}
	}
	if (EFI_ERROR (Status)) {
	ShellStatus = EfiCodeToShellCode (Status);
	ShellPrintHiiEx (
	-1, -1, NULL,
	STRING_TOKEN (STR_SETFDT_ERROR),
	mFdtPlatformDxeHiiHandle,
	Status
	);
	goto Error;
	}

	//
	// Update the preferred device path for the FDT if asked for.
	//
	if (FilePath) {
	ValueStr = ShellCommandLineGetRawValue (ParamPackage, 1);
	ShellPrintHiiEx (
	-1, -1, NULL,
	STRING_TOKEN (STR_SETFDT_UPDATING),
	mFdtPlatformDxeHiiHandle
	);
	ShellStatus = UpdateFdtTextDevicePath (Shell, ValueStr);
	if (ShellStatus != SHELL_SUCCESS) {
	goto Error;
	}
	}

	//
	// Run the FDT installation process if asked for.
	//
	if (ShellCommandLineGetFlag (ParamPackage, L"-i")) {
	ShellPrintHiiEx (
	-1, -1, NULL,
	STRING_TOKEN (STR_SETFDT_INSTALLING),
	mFdtPlatformDxeHiiHandle
	);
	Status = RunFdtInstallation (&TextDevicePath);
	ShellStatus = EfiCodeToShellCode (Status);
	if (!EFI_ERROR (Status)) {
	ShellPrintHiiEx (
	-1, -1, NULL,
	STRING_TOKEN (STR_SETFDT_INSTALL_SUCCEEDED),
	mFdtPlatformDxeHiiHandle,
	TextDevicePath
	);
	FreePool (TextDevicePath);
	} else {
	if (Status == EFI_INVALID_PARAMETER) {
	ShellPrintHiiEx (
	-1, -1, NULL,
	STRING_TOKEN (STR_SETFDT_INVALID_DEVICE_PATH),
	mFdtPlatformDxeHiiHandle
	);
	} else {
	ShellPrintHiiEx (
	-1, -1, NULL,
	STRING_TOKEN (STR_SETFDT_ERROR),
	mFdtPlatformDxeHiiHandle,
	Status
	);
	}
	DisplayFdtDevicePaths ();
	}
	}

	Error:
	gBS->UninstallMultipleProtocolInterfaces (
	gImageHandle,
	&gEfiShellProtocolGuid, Shell,
	&gEfiShellParametersProtocolGuid, ShellParameters,
	NULL
	);
	ShellCommandLineFreeVarList (ParamPackage);

	return ShellStatus;
	}

	/**
	This is the shell command "setfdt" help handler function. This
	function returns the formatted help for the "setfdt" command.
	The format matchs that in Appendix B of the revision 2.1 of the
	UEFI Shell Specification.

	@param[in] This The instance of the EFI_SHELL_DYNAMIC_COMMAND_PROTOCOL.
	@param[in] Language The pointer to the language string to use.

	@return CHAR16* Pool allocated help string, must be freed by caller.
	**/
	CHAR16*
	EFIAPI
	ShellDynCmdSetFdtGetHelp (
	IN EFI_SHELL_DYNAMIC_COMMAND_PROTOCOL *This,
	IN CONST CHAR8 *Language
	)
	{
	//
	// This allocates memory. The caller has to free the allocated memory.
	//
	return HiiGetString (
	mFdtPlatformDxeHiiHandle,
	STRING_TOKEN (STR_GET_HELP_SETFDT),
	Language
	);
	}