FatPkg/EnhancedFatDxe/Fat.c - third_party/edk2 - Git at Google

 /** @file
   Fat File System driver routines that support EFI driver model.

 Copyright (c) 2005 - 2014, 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 "Fat.h"

 /**

   Register Driver Binding protocol for this driver.

   @param  ImageHandle           - Handle for the image of this driver.
   @param  SystemTable           - Pointer to the EFI System Table.

   @retval EFI_SUCCESS           - Driver loaded.
   @return other                 - Driver not loaded.

 **/
 EFI_STATUS
 EFIAPI
 FatEntryPoint (
   IN EFI_HANDLE         ImageHandle,
   IN EFI_SYSTEM_TABLE   *SystemTable
   );

 /**

   Unload function for this image. Uninstall DriverBinding protocol.

   @param ImageHandle           - Handle for the image of this driver.

   @retval EFI_SUCCESS           - Driver unloaded successfully.
   @return other                 - Driver can not unloaded.

 **/
 EFI_STATUS
 EFIAPI
 FatUnload (
   IN EFI_HANDLE         ImageHandle
   );

 /**

   Test to see if this driver can add a file system to ControllerHandle.
   ControllerHandle must support both Disk IO and Block IO protocols.

   @param  This                  - Protocol instance pointer.
   @param  ControllerHandle      - Handle of device to test.
   @param  RemainingDevicePath   - Not used.

   @retval EFI_SUCCESS           - This driver supports this device.
   @retval EFI_ALREADY_STARTED   - This driver is already running on this device.
   @return other                 - This driver does not support this device.

 **/
 EFI_STATUS
 EFIAPI
 FatDriverBindingSupported (
   IN EFI_DRIVER_BINDING_PROTOCOL  *This,
   IN EFI_HANDLE                   Controller,
   IN EFI_DEVICE_PATH_PROTOCOL     *RemainingDevicePath
   );

 /**

   Start this driver on ControllerHandle by opening a Block IO and Disk IO
   protocol, reading Device Path. Add a Simple File System protocol to
   ControllerHandle if the media contains a valid file system.

   @param  This                  - Protocol instance pointer.
   @param  ControllerHandle      - Handle of device to bind driver to.
   @param  RemainingDevicePath   - Not used.

   @retval EFI_SUCCESS           - This driver is added to DeviceHandle.
   @retval EFI_ALREADY_STARTED   - This driver is already running on DeviceHandle.
   @retval EFI_OUT_OF_RESOURCES  - Can not allocate the memory.
   @return other                 - This driver does not support this device.

 **/
 EFI_STATUS
 EFIAPI
 FatDriverBindingStart (
   IN EFI_DRIVER_BINDING_PROTOCOL  *This,
   IN EFI_HANDLE                   Controller,
   IN EFI_DEVICE_PATH_PROTOCOL     *RemainingDevicePath
   );

 /**

   Stop this driver on ControllerHandle.

   @param  This                  - Protocol instance pointer.
   @param  ControllerHandle      - Handle of device to stop driver on.
   @param  NumberOfChildren      - Not used.
   @param  ChildHandleBuffer     - Not used.

   @retval EFI_SUCCESS           - This driver is removed DeviceHandle.
   @return other                 - This driver was not removed from this device.

 **/
 EFI_STATUS
 EFIAPI
 FatDriverBindingStop (
   IN  EFI_DRIVER_BINDING_PROTOCOL  *This,
   IN  EFI_HANDLE                   Controller,
   IN  UINTN                        NumberOfChildren,
   IN  EFI_HANDLE                   *ChildHandleBuffer
   );

 //
 // DriverBinding protocol instance
 //
 EFI_DRIVER_BINDING_PROTOCOL gFatDriverBinding = {
   FatDriverBindingSupported,
   FatDriverBindingStart,
   FatDriverBindingStop,
   0xa,
   NULL,
   NULL
 };

 /**

   Register Driver Binding protocol for this driver.

   @param  ImageHandle           - Handle for the image of this driver.
   @param  SystemTable           - Pointer to the EFI System Table.

   @retval EFI_SUCCESS           - Driver loaded.
   @return other                 - Driver not loaded.

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

   //
   // Initialize the EFI Driver Library
   //
   Status = EfiLibInstallDriverBindingComponentName2 (
              ImageHandle,
              SystemTable,
              &gFatDriverBinding,
              ImageHandle,
              &gFatComponentName,
              &gFatComponentName2
              );
   ASSERT_EFI_ERROR (Status);

   return Status;
 }

 /**

   Unload function for this image. Uninstall DriverBinding protocol.

   @param ImageHandle           - Handle for the image of this driver.

   @retval EFI_SUCCESS           - Driver unloaded successfully.
   @return other                 - Driver can not unloaded.

 **/
 EFI_STATUS
 EFIAPI
 FatUnload (
   IN EFI_HANDLE  ImageHandle
   )
 {
   EFI_STATUS  Status;
   EFI_HANDLE  *DeviceHandleBuffer;
   UINTN       DeviceHandleCount;
   UINTN       Index;
   VOID        *ComponentName;
   VOID        *ComponentName2;

   Status = gBS->LocateHandleBuffer (
                   AllHandles,
                   NULL,
                   NULL,
                   &DeviceHandleCount,
                   &DeviceHandleBuffer
                   );
   if (EFI_ERROR (Status)) {
     return Status;
   }

   for (Index = 0; Index < DeviceHandleCount; Index++) {
     Status = EfiTestManagedDevice (DeviceHandleBuffer[Index], ImageHandle, &gEfiDiskIoProtocolGuid);
     if (!EFI_ERROR (Status)) {
       Status = gBS->DisconnectController (
                       DeviceHandleBuffer[Index],
                       ImageHandle,
                       NULL
                       );
       if (EFI_ERROR (Status)) {
         break;
       }
     }
   }

   if (Index == DeviceHandleCount) {
     //
     // Driver is stopped successfully.
     //
     Status = gBS->HandleProtocol (ImageHandle, &gEfiComponentNameProtocolGuid, &ComponentName);
     if (EFI_ERROR (Status)) {
       ComponentName = NULL;
     }

     Status = gBS->HandleProtocol (ImageHandle, &gEfiComponentName2ProtocolGuid, &ComponentName2);
     if (EFI_ERROR (Status)) {
       ComponentName2 = NULL;
     }

     if (ComponentName == NULL) {
       if (ComponentName2 == NULL) {
         Status = gBS->UninstallMultipleProtocolInterfaces (
                         ImageHandle,
                         &gEfiDriverBindingProtocolGuid,  &gFatDriverBinding,
                         NULL
                         );
       } else {
         Status = gBS->UninstallMultipleProtocolInterfaces (
                         ImageHandle,
                         &gEfiDriverBindingProtocolGuid,  &gFatDriverBinding,
                         &gEfiComponentName2ProtocolGuid, ComponentName2,
                         NULL
                         );
       }
     } else {
       if (ComponentName2 == NULL) {
         Status = gBS->UninstallMultipleProtocolInterfaces (
                         ImageHandle,
                         &gEfiDriverBindingProtocolGuid,  &gFatDriverBinding,
                         &gEfiComponentNameProtocolGuid,  ComponentName,
                         NULL
                         );
       } else {
         Status = gBS->UninstallMultipleProtocolInterfaces (
                         ImageHandle,
                         &gEfiDriverBindingProtocolGuid,  &gFatDriverBinding,
                         &gEfiComponentNameProtocolGuid,  ComponentName,
                         &gEfiComponentName2ProtocolGuid, ComponentName2,
                         NULL
                         );
       }
     }
   }

   if (DeviceHandleBuffer != NULL) {
     FreePool (DeviceHandleBuffer);
   }

   return Status;
 }

 /**

   Test to see if this driver can add a file system to ControllerHandle.
   ControllerHandle must support both Disk IO and Block IO protocols.

   @param  This                  - Protocol instance pointer.
   @param  ControllerHandle      - Handle of device to test.
   @param  RemainingDevicePath   - Not used.

   @retval EFI_SUCCESS           - This driver supports this device.
   @retval EFI_ALREADY_STARTED   - This driver is already running on this device.
   @return other                 - This driver does not support this device.

 **/
 EFI_STATUS
 EFIAPI
 FatDriverBindingSupported (
   IN EFI_DRIVER_BINDING_PROTOCOL  *This,
   IN EFI_HANDLE                   ControllerHandle,
   IN EFI_DEVICE_PATH_PROTOCOL     *RemainingDevicePath
   )
 {
   EFI_STATUS            Status;
   EFI_DISK_IO_PROTOCOL  *DiskIo;

   //
   // Open the IO Abstraction(s) needed to perform the supported test
   //
   Status = gBS->OpenProtocol (
                   ControllerHandle,
                   &gEfiDiskIoProtocolGuid,
                   (VOID **) &DiskIo,
                   This->DriverBindingHandle,
                   ControllerHandle,
                   EFI_OPEN_PROTOCOL_BY_DRIVER
                   );

   if (EFI_ERROR (Status)) {
     return Status;
   }
   //
   // Close the I/O Abstraction(s) used to perform the supported test
   //
   gBS->CloseProtocol (
          ControllerHandle,
          &gEfiDiskIoProtocolGuid,
          This->DriverBindingHandle,
          ControllerHandle
          );

   //
   // Open the IO Abstraction(s) needed to perform the supported test
   //
   Status = gBS->OpenProtocol (
                   ControllerHandle,
                   &gEfiBlockIoProtocolGuid,
                   NULL,
                   This->DriverBindingHandle,
                   ControllerHandle,
                   EFI_OPEN_PROTOCOL_TEST_PROTOCOL
                   );

   return Status;
 }

 /**

   Start this driver on ControllerHandle by opening a Block IO and Disk IO
   protocol, reading Device Path. Add a Simple File System protocol to
   ControllerHandle if the media contains a valid file system.

   @param  This                  - Protocol instance pointer.
   @param  ControllerHandle      - Handle of device to bind driver to.
   @param  RemainingDevicePath   - Not used.

   @retval EFI_SUCCESS           - This driver is added to DeviceHandle.
   @retval EFI_ALREADY_STARTED   - This driver is already running on DeviceHandle.
   @retval EFI_OUT_OF_RESOURCES  - Can not allocate the memory.
   @return other                 - This driver does not support this device.

 **/
 EFI_STATUS
 EFIAPI
 FatDriverBindingStart (
   IN EFI_DRIVER_BINDING_PROTOCOL  *This,
   IN EFI_HANDLE                   ControllerHandle,
   IN EFI_DEVICE_PATH_PROTOCOL     *RemainingDevicePath
   )
 {
   EFI_STATUS            Status;
   EFI_BLOCK_IO_PROTOCOL *BlockIo;
   EFI_DISK_IO_PROTOCOL  *DiskIo;
   EFI_DISK_IO2_PROTOCOL *DiskIo2;
   BOOLEAN               LockedByMe;

   LockedByMe = FALSE;
   //
   // Acquire the lock.
   // If caller has already acquired the lock, cannot lock it again.
   //
   Status = FatAcquireLockOrFail ();
   if (!EFI_ERROR (Status)) {
     LockedByMe = TRUE;
   }

   Status = InitializeUnicodeCollationSupport (This->DriverBindingHandle);
   if (EFI_ERROR (Status)) {
     goto Exit;
   }
   //
   // Open our required BlockIo and DiskIo
   //
   Status = gBS->OpenProtocol (
                   ControllerHandle,
                   &gEfiBlockIoProtocolGuid,
                   (VOID **) &BlockIo,
                   This->DriverBindingHandle,
                   ControllerHandle,
                   EFI_OPEN_PROTOCOL_GET_PROTOCOL
                   );
   if (EFI_ERROR (Status)) {
     goto Exit;
   }

   Status = gBS->OpenProtocol (
                   ControllerHandle,
                   &gEfiDiskIoProtocolGuid,
                   (VOID **) &DiskIo,
                   This->DriverBindingHandle,
                   ControllerHandle,
                   EFI_OPEN_PROTOCOL_BY_DRIVER
                   );
   if (EFI_ERROR (Status)) {
     goto Exit;
   }

   Status = gBS->OpenProtocol (
                   ControllerHandle,
                   &gEfiDiskIo2ProtocolGuid,
                   (VOID **) &DiskIo2,
                   This->DriverBindingHandle,
                   ControllerHandle,
                   EFI_OPEN_PROTOCOL_BY_DRIVER
                   );
   if (EFI_ERROR (Status)) {
     DiskIo2 = NULL;
   }

   //
   // Allocate Volume structure. In FatAllocateVolume(), Resources
   // are allocated with protocol installed and cached initialized
   //
   Status = FatAllocateVolume (ControllerHandle, DiskIo, DiskIo2, BlockIo);

   //
   // When the media changes on a device it will Reinstall the BlockIo interaface.
   // This will cause a call to our Stop(), and a subsequent reentrant call to our
   // Start() successfully. We should leave the device open when this happen.
   //
   if (EFI_ERROR (Status)) {
     Status = gBS->OpenProtocol (
                     ControllerHandle,
                     &gEfiSimpleFileSystemProtocolGuid,
                     NULL,
                     This->DriverBindingHandle,
                     ControllerHandle,
                     EFI_OPEN_PROTOCOL_TEST_PROTOCOL
                     );
     if (EFI_ERROR (Status)) {
       gBS->CloseProtocol (
              ControllerHandle,
              &gEfiDiskIoProtocolGuid,
              This->DriverBindingHandle,
              ControllerHandle
              );
       gBS->CloseProtocol (
              ControllerHandle,
              &gEfiDiskIo2ProtocolGuid,
              This->DriverBindingHandle,
              ControllerHandle
              );
     }
   }

 Exit:
   //
   // Unlock if locked by myself.
   //
   if (LockedByMe) {
     FatReleaseLock ();
   }
   return Status;
 }

 /**

   Stop this driver on ControllerHandle.

   @param  This                  - Protocol instance pointer.
   @param  ControllerHandle      - Handle of device to stop driver on.
   @param  NumberOfChildren      - Not used.
   @param  ChildHandleBuffer     - Not used.

   @retval EFI_SUCCESS           - This driver is removed DeviceHandle.
   @return other                 - This driver was not removed from this device.

 **/
 EFI_STATUS
 EFIAPI
 FatDriverBindingStop (
   IN  EFI_DRIVER_BINDING_PROTOCOL   *This,
   IN  EFI_HANDLE                    ControllerHandle,
   IN  UINTN                         NumberOfChildren,
   IN  EFI_HANDLE                    *ChildHandleBuffer
   )
 {
   EFI_STATUS                      Status;
   EFI_SIMPLE_FILE_SYSTEM_PROTOCOL *FileSystem;
   FAT_VOLUME                      *Volume;
   EFI_DISK_IO2_PROTOCOL           *DiskIo2;

   DiskIo2 = NULL;
   //
   // Get our context back
   //
   Status = gBS->OpenProtocol (
                   ControllerHandle,
                   &gEfiSimpleFileSystemProtocolGuid,
                   (VOID **) &FileSystem,
                   This->DriverBindingHandle,
                   ControllerHandle,
                   EFI_OPEN_PROTOCOL_GET_PROTOCOL
                   );

   if (!EFI_ERROR (Status)) {
     Volume  = VOLUME_FROM_VOL_INTERFACE (FileSystem);
     DiskIo2 = Volume->DiskIo2;
     Status  = FatAbandonVolume (Volume);
   }

   if (!EFI_ERROR (Status)) {
     if (DiskIo2 != NULL) {
       Status = gBS->CloseProtocol (
         ControllerHandle,
         &gEfiDiskIo2ProtocolGuid,
         This->DriverBindingHandle,
         ControllerHandle
         );
       ASSERT_EFI_ERROR (Status);
     }
     Status = gBS->CloseProtocol (
       ControllerHandle,
       &gEfiDiskIoProtocolGuid,
       This->DriverBindingHandle,
       ControllerHandle
       );
     ASSERT_EFI_ERROR (Status);
   }

   return Status;
 }
	/** @file
	Fat File System driver routines that support EFI driver model.

	Copyright (c) 2005 - 2014, 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 "Fat.h"

	/**

	Register Driver Binding protocol for this driver.

	@param ImageHandle - Handle for the image of this driver.
	@param SystemTable - Pointer to the EFI System Table.

	@retval EFI_SUCCESS - Driver loaded.
	@return other - Driver not loaded.

	**/
	EFI_STATUS
	EFIAPI
	FatEntryPoint (
	IN EFI_HANDLE ImageHandle,
	IN EFI_SYSTEM_TABLE *SystemTable
	);

	/**

	Unload function for this image. Uninstall DriverBinding protocol.

	@param ImageHandle - Handle for the image of this driver.

	@retval EFI_SUCCESS - Driver unloaded successfully.
	@return other - Driver can not unloaded.

	**/
	EFI_STATUS
	EFIAPI
	FatUnload (
	IN EFI_HANDLE ImageHandle
	);

	/**

	Test to see if this driver can add a file system to ControllerHandle.
	ControllerHandle must support both Disk IO and Block IO protocols.

	@param This - Protocol instance pointer.
	@param ControllerHandle - Handle of device to test.
	@param RemainingDevicePath - Not used.

	@retval EFI_SUCCESS - This driver supports this device.
	@retval EFI_ALREADY_STARTED - This driver is already running on this device.
	@return other - This driver does not support this device.

	**/
	EFI_STATUS
	EFIAPI
	FatDriverBindingSupported (
	IN EFI_DRIVER_BINDING_PROTOCOL *This,
	IN EFI_HANDLE Controller,
	IN EFI_DEVICE_PATH_PROTOCOL *RemainingDevicePath
	);

	/**

	Start this driver on ControllerHandle by opening a Block IO and Disk IO
	protocol, reading Device Path. Add a Simple File System protocol to
	ControllerHandle if the media contains a valid file system.

	@param This - Protocol instance pointer.
	@param ControllerHandle - Handle of device to bind driver to.
	@param RemainingDevicePath - Not used.

	@retval EFI_SUCCESS - This driver is added to DeviceHandle.
	@retval EFI_ALREADY_STARTED - This driver is already running on DeviceHandle.
	@retval EFI_OUT_OF_RESOURCES - Can not allocate the memory.
	@return other - This driver does not support this device.

	**/
	EFI_STATUS
	EFIAPI
	FatDriverBindingStart (
	IN EFI_DRIVER_BINDING_PROTOCOL *This,
	IN EFI_HANDLE Controller,
	IN EFI_DEVICE_PATH_PROTOCOL *RemainingDevicePath
	);

	/**

	Stop this driver on ControllerHandle.

	@param This - Protocol instance pointer.
	@param ControllerHandle - Handle of device to stop driver on.
	@param NumberOfChildren - Not used.
	@param ChildHandleBuffer - Not used.

	@retval EFI_SUCCESS - This driver is removed DeviceHandle.
	@return other - This driver was not removed from this device.

	**/
	EFI_STATUS
	EFIAPI
	FatDriverBindingStop (
	IN EFI_DRIVER_BINDING_PROTOCOL *This,
	IN EFI_HANDLE Controller,
	IN UINTN NumberOfChildren,
	IN EFI_HANDLE *ChildHandleBuffer
	);

	//
	// DriverBinding protocol instance
	//
	EFI_DRIVER_BINDING_PROTOCOL gFatDriverBinding = {
	FatDriverBindingSupported,
	FatDriverBindingStart,
	FatDriverBindingStop,
	0xa,
	NULL,
	NULL
	};

	/**

	Register Driver Binding protocol for this driver.

	@param ImageHandle - Handle for the image of this driver.
	@param SystemTable - Pointer to the EFI System Table.

	@retval EFI_SUCCESS - Driver loaded.
	@return other - Driver not loaded.

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

	//
	// Initialize the EFI Driver Library
	//
	Status = EfiLibInstallDriverBindingComponentName2 (
	ImageHandle,
	SystemTable,
	&gFatDriverBinding,
	ImageHandle,
	&gFatComponentName,
	&gFatComponentName2
	);
	ASSERT_EFI_ERROR (Status);

	return Status;
	}

	/**

	Unload function for this image. Uninstall DriverBinding protocol.

	@param ImageHandle - Handle for the image of this driver.

	@retval EFI_SUCCESS - Driver unloaded successfully.
	@return other - Driver can not unloaded.

	**/
	EFI_STATUS
	EFIAPI
	FatUnload (
	IN EFI_HANDLE ImageHandle
	)
	{
	EFI_STATUS Status;
	EFI_HANDLE *DeviceHandleBuffer;
	UINTN DeviceHandleCount;
	UINTN Index;
	VOID *ComponentName;
	VOID *ComponentName2;

	Status = gBS->LocateHandleBuffer (
	AllHandles,
	NULL,
	NULL,
	&DeviceHandleCount,
	&DeviceHandleBuffer
	);
	if (EFI_ERROR (Status)) {
	return Status;
	}

	for (Index = 0; Index < DeviceHandleCount; Index++) {
	Status = EfiTestManagedDevice (DeviceHandleBuffer[Index], ImageHandle, &gEfiDiskIoProtocolGuid);
	if (!EFI_ERROR (Status)) {
	Status = gBS->DisconnectController (
	DeviceHandleBuffer[Index],
	ImageHandle,
	NULL
	);
	if (EFI_ERROR (Status)) {
	break;
	}
	}
	}

	if (Index == DeviceHandleCount) {
	//
	// Driver is stopped successfully.
	//
	Status = gBS->HandleProtocol (ImageHandle, &gEfiComponentNameProtocolGuid, &ComponentName);
	if (EFI_ERROR (Status)) {
	ComponentName = NULL;
	}

	Status = gBS->HandleProtocol (ImageHandle, &gEfiComponentName2ProtocolGuid, &ComponentName2);
	if (EFI_ERROR (Status)) {
	ComponentName2 = NULL;
	}

	if (ComponentName == NULL) {
	if (ComponentName2 == NULL) {
	Status = gBS->UninstallMultipleProtocolInterfaces (
	ImageHandle,
	&gEfiDriverBindingProtocolGuid, &gFatDriverBinding,
	NULL
	);
	} else {
	Status = gBS->UninstallMultipleProtocolInterfaces (
	ImageHandle,
	&gEfiDriverBindingProtocolGuid, &gFatDriverBinding,
	&gEfiComponentName2ProtocolGuid, ComponentName2,
	NULL
	);
	}
	} else {
	if (ComponentName2 == NULL) {
	Status = gBS->UninstallMultipleProtocolInterfaces (
	ImageHandle,
	&gEfiDriverBindingProtocolGuid, &gFatDriverBinding,
	&gEfiComponentNameProtocolGuid, ComponentName,
	NULL
	);
	} else {
	Status = gBS->UninstallMultipleProtocolInterfaces (
	ImageHandle,
	&gEfiDriverBindingProtocolGuid, &gFatDriverBinding,
	&gEfiComponentNameProtocolGuid, ComponentName,
	&gEfiComponentName2ProtocolGuid, ComponentName2,
	NULL
	);
	}
	}
	}

	if (DeviceHandleBuffer != NULL) {
	FreePool (DeviceHandleBuffer);
	}

	return Status;
	}

	/**

	Test to see if this driver can add a file system to ControllerHandle.
	ControllerHandle must support both Disk IO and Block IO protocols.

	@param This - Protocol instance pointer.
	@param ControllerHandle - Handle of device to test.
	@param RemainingDevicePath - Not used.

	@retval EFI_SUCCESS - This driver supports this device.
	@retval EFI_ALREADY_STARTED - This driver is already running on this device.
	@return other - This driver does not support this device.

	**/
	EFI_STATUS
	EFIAPI
	FatDriverBindingSupported (
	IN EFI_DRIVER_BINDING_PROTOCOL *This,
	IN EFI_HANDLE ControllerHandle,
	IN EFI_DEVICE_PATH_PROTOCOL *RemainingDevicePath
	)
	{
	EFI_STATUS Status;
	EFI_DISK_IO_PROTOCOL *DiskIo;

	//
	// Open the IO Abstraction(s) needed to perform the supported test
	//
	Status = gBS->OpenProtocol (
	ControllerHandle,
	&gEfiDiskIoProtocolGuid,
	(VOID **) &DiskIo,
	This->DriverBindingHandle,
	ControllerHandle,
	EFI_OPEN_PROTOCOL_BY_DRIVER
	);

	if (EFI_ERROR (Status)) {
	return Status;
	}
	//
	// Close the I/O Abstraction(s) used to perform the supported test
	//
	gBS->CloseProtocol (
	ControllerHandle,
	&gEfiDiskIoProtocolGuid,
	This->DriverBindingHandle,
	ControllerHandle
	);

	//
	// Open the IO Abstraction(s) needed to perform the supported test
	//
	Status = gBS->OpenProtocol (
	ControllerHandle,
	&gEfiBlockIoProtocolGuid,
	NULL,
	This->DriverBindingHandle,
	ControllerHandle,
	EFI_OPEN_PROTOCOL_TEST_PROTOCOL
	);

	return Status;
	}

	/**

	Start this driver on ControllerHandle by opening a Block IO and Disk IO
	protocol, reading Device Path. Add a Simple File System protocol to
	ControllerHandle if the media contains a valid file system.

	@param This - Protocol instance pointer.
	@param ControllerHandle - Handle of device to bind driver to.
	@param RemainingDevicePath - Not used.

	@retval EFI_SUCCESS - This driver is added to DeviceHandle.
	@retval EFI_ALREADY_STARTED - This driver is already running on DeviceHandle.
	@retval EFI_OUT_OF_RESOURCES - Can not allocate the memory.
	@return other - This driver does not support this device.

	**/
	EFI_STATUS
	EFIAPI
	FatDriverBindingStart (
	IN EFI_DRIVER_BINDING_PROTOCOL *This,
	IN EFI_HANDLE ControllerHandle,
	IN EFI_DEVICE_PATH_PROTOCOL *RemainingDevicePath
	)
	{
	EFI_STATUS Status;
	EFI_BLOCK_IO_PROTOCOL *BlockIo;
	EFI_DISK_IO_PROTOCOL *DiskIo;
	EFI_DISK_IO2_PROTOCOL *DiskIo2;
	BOOLEAN LockedByMe;

	LockedByMe = FALSE;
	//
	// Acquire the lock.
	// If caller has already acquired the lock, cannot lock it again.
	//
	Status = FatAcquireLockOrFail ();
	if (!EFI_ERROR (Status)) {
	LockedByMe = TRUE;
	}

	Status = InitializeUnicodeCollationSupport (This->DriverBindingHandle);
	if (EFI_ERROR (Status)) {
	goto Exit;
	}
	//
	// Open our required BlockIo and DiskIo
	//
	Status = gBS->OpenProtocol (
	ControllerHandle,
	&gEfiBlockIoProtocolGuid,
	(VOID **) &BlockIo,
	This->DriverBindingHandle,
	ControllerHandle,
	EFI_OPEN_PROTOCOL_GET_PROTOCOL
	);
	if (EFI_ERROR (Status)) {
	goto Exit;
	}

	Status = gBS->OpenProtocol (
	ControllerHandle,
	&gEfiDiskIoProtocolGuid,
	(VOID **) &DiskIo,
	This->DriverBindingHandle,
	ControllerHandle,
	EFI_OPEN_PROTOCOL_BY_DRIVER
	);
	if (EFI_ERROR (Status)) {
	goto Exit;
	}

	Status = gBS->OpenProtocol (
	ControllerHandle,
	&gEfiDiskIo2ProtocolGuid,
	(VOID **) &DiskIo2,
	This->DriverBindingHandle,
	ControllerHandle,
	EFI_OPEN_PROTOCOL_BY_DRIVER
	);
	if (EFI_ERROR (Status)) {
	DiskIo2 = NULL;
	}

	//
	// Allocate Volume structure. In FatAllocateVolume(), Resources
	// are allocated with protocol installed and cached initialized
	//
	Status = FatAllocateVolume (ControllerHandle, DiskIo, DiskIo2, BlockIo);

	//
	// When the media changes on a device it will Reinstall the BlockIo interaface.
	// This will cause a call to our Stop(), and a subsequent reentrant call to our
	// Start() successfully. We should leave the device open when this happen.
	//
	if (EFI_ERROR (Status)) {
	Status = gBS->OpenProtocol (
	ControllerHandle,
	&gEfiSimpleFileSystemProtocolGuid,
	NULL,
	This->DriverBindingHandle,
	ControllerHandle,
	EFI_OPEN_PROTOCOL_TEST_PROTOCOL
	);
	if (EFI_ERROR (Status)) {
	gBS->CloseProtocol (
	ControllerHandle,
	&gEfiDiskIoProtocolGuid,
	This->DriverBindingHandle,
	ControllerHandle
	);
	gBS->CloseProtocol (
	ControllerHandle,
	&gEfiDiskIo2ProtocolGuid,
	This->DriverBindingHandle,
	ControllerHandle
	);
	}
	}

	Exit:
	//
	// Unlock if locked by myself.
	//
	if (LockedByMe) {
	FatReleaseLock ();
	}
	return Status;
	}

	/**

	Stop this driver on ControllerHandle.

	@param This - Protocol instance pointer.
	@param ControllerHandle - Handle of device to stop driver on.
	@param NumberOfChildren - Not used.
	@param ChildHandleBuffer - Not used.

	@retval EFI_SUCCESS - This driver is removed DeviceHandle.
	@return other - This driver was not removed from this device.

	**/
	EFI_STATUS
	EFIAPI
	FatDriverBindingStop (
	IN EFI_DRIVER_BINDING_PROTOCOL *This,
	IN EFI_HANDLE ControllerHandle,
	IN UINTN NumberOfChildren,
	IN EFI_HANDLE *ChildHandleBuffer
	)
	{
	EFI_STATUS Status;
	EFI_SIMPLE_FILE_SYSTEM_PROTOCOL *FileSystem;
	FAT_VOLUME *Volume;
	EFI_DISK_IO2_PROTOCOL *DiskIo2;

	DiskIo2 = NULL;
	//
	// Get our context back
	//
	Status = gBS->OpenProtocol (
	ControllerHandle,
	&gEfiSimpleFileSystemProtocolGuid,
	(VOID **) &FileSystem,
	This->DriverBindingHandle,
	ControllerHandle,
	EFI_OPEN_PROTOCOL_GET_PROTOCOL
	);

	if (!EFI_ERROR (Status)) {
	Volume = VOLUME_FROM_VOL_INTERFACE (FileSystem);
	DiskIo2 = Volume->DiskIo2;
	Status = FatAbandonVolume (Volume);
	}

	if (!EFI_ERROR (Status)) {
	if (DiskIo2 != NULL) {
	Status = gBS->CloseProtocol (
	ControllerHandle,
	&gEfiDiskIo2ProtocolGuid,
	This->DriverBindingHandle,
	ControllerHandle
	);
	ASSERT_EFI_ERROR (Status);
	}
	Status = gBS->CloseProtocol (
	ControllerHandle,
	&gEfiDiskIoProtocolGuid,
	This->DriverBindingHandle,
	ControllerHandle
	);
	ASSERT_EFI_ERROR (Status);
	}

	return Status;
	}