audk/MdeModulePkg/Bus/Scsi/ScsiDiskDxe/ScsiDisk.c

/** @file
  SCSI disk driver that layers on every SCSI IO protocol in the system.

Copyright (c) 2006 - 2008, Intel Corporation. <BR>
All rights reserved. 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 <PiDxe.h>


#include <Protocol/ScsiIo.h>
#include <Protocol/ComponentName.h>
#include <Protocol/BlockIo.h>
#include <Protocol/DriverBinding.h>
#include <Protocol/ScsiPassThruExt.h>

#include <Library/DebugLib.h>
#include <Library/UefiDriverEntryPoint.h>
#include <Library/UefiLib.h>
#include <Library/BaseMemoryLib.h>
#include <Library/ScsiLib.h>
#include <Library/UefiBootServicesTableLib.h>

#include "ScsiDisk.h"

EFI_DRIVER_BINDING_PROTOCOL gScsiDiskDriverBinding = {
  ScsiDiskDriverBindingSupported,
  ScsiDiskDriverBindingStart,
  ScsiDiskDriverBindingStop,
  0xa,
  NULL,
  NULL
};

/**
  The user Entry Point for module ScsiDisk. 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
InitializeScsiDisk(
  IN EFI_HANDLE           ImageHandle,
  IN EFI_SYSTEM_TABLE     *SystemTable
  )
{
  EFI_STATUS              Status;

  //
  // Install driver model protocol(s).
  //
  Status = EfiLibInstallDriverBindingComponentName2 (
             ImageHandle,
             SystemTable,
             &gScsiDiskDriverBinding,
             ImageHandle,
             &gScsiDiskComponentName,
             &gScsiDiskComponentName2
             );
  ASSERT_EFI_ERROR (Status);


  return Status;
}

EFI_STATUS
EFIAPI
ScsiDiskDriverBindingSupported (
  IN EFI_DRIVER_BINDING_PROTOCOL  *This,
  IN EFI_HANDLE                   Controller,
  IN EFI_DEVICE_PATH_PROTOCOL     *RemainingDevicePath
  )
/*++

Routine Description:

  Test to see if this driver supports ControllerHandle. Any ControllerHandle
  that has ScsiIoProtocol installed will be supported.

Arguments:

  This                - Protocol instance pointer.
  Controller          - Handle of device to test
  RemainingDevicePath - Not used

Returns:

  EFI_SUCCESS         - This driver supports this device.
  EFI_UNSUPPORTED     - This driver does not support this device.
  
  
--*/
{
  EFI_STATUS            Status;
  EFI_SCSI_IO_PROTOCOL  *ScsiIo;
  UINT8                 DeviceType;

  Status = gBS->OpenProtocol (
                  Controller,
                  &gEfiScsiIoProtocolGuid,
                  (VOID **) &ScsiIo,
                  This->DriverBindingHandle,
                  Controller,
                  EFI_OPEN_PROTOCOL_BY_DRIVER
                  );
  if (EFI_ERROR (Status)) {
    return Status;
  }

  Status = ScsiIo->GetDeviceType (ScsiIo, &DeviceType);
  if (!EFI_ERROR (Status)) {
    if ((DeviceType == EFI_SCSI_TYPE_DISK) || (DeviceType == EFI_SCSI_TYPE_CDROM)) {
      Status = EFI_SUCCESS;
    } else {
      Status = EFI_UNSUPPORTED;
    }
  }

  gBS->CloseProtocol (
         Controller,
         &gEfiScsiIoProtocolGuid,
         This->DriverBindingHandle,
         Controller
         );
  return Status;
}

EFI_STATUS
EFIAPI
ScsiDiskDriverBindingStart (
  IN EFI_DRIVER_BINDING_PROTOCOL  *This,
  IN EFI_HANDLE                   Controller,
  IN EFI_DEVICE_PATH_PROTOCOL     *RemainingDevicePath
  )
/*++

Routine Description:

  Start SCSI Disk Driver, and attach BlockIoProtocol to it.
  
Arguments:

  This                - Protocol instance pointer.
  Controller          - Handle of device to test
  RemainingDevicePath - Not used

Returns:

  EFI_SUCCESS         - This driver supports this device.
  EFI_UNSUPPORTED     - This driver does not support this device.
  
  
--*/
{
  EFI_STATUS            Status;
  EFI_SCSI_IO_PROTOCOL  *ScsiIo;
  SCSI_DISK_DEV         *ScsiDiskDevice;
  BOOLEAN               Temp;
  UINT8                 Index;
  UINT8                 MaxRetry;
  BOOLEAN               NeedRetry;

  Status = gBS->AllocatePool (
                  EfiBootServicesData,
                  sizeof (SCSI_DISK_DEV),
                  (VOID **) &ScsiDiskDevice
                  );
  if (EFI_ERROR (Status)) {
    return Status;
  }

  ZeroMem (ScsiDiskDevice, sizeof (SCSI_DISK_DEV));

  Status = gBS->OpenProtocol (
                  Controller,
                  &gEfiScsiIoProtocolGuid,
                  (VOID **) &ScsiIo,
                  This->DriverBindingHandle,
                  Controller,
                  EFI_OPEN_PROTOCOL_BY_DRIVER
                  );
  if (EFI_ERROR (Status)) {
    gBS->FreePool (ScsiDiskDevice);
    return Status;
  }

  ScsiDiskDevice->Signature         = SCSI_DISK_DEV_SIGNATURE;
  ScsiDiskDevice->ScsiIo            = ScsiIo;
  ScsiDiskDevice->BlkIo.Media       = &ScsiDiskDevice->BlkIoMedia;
  ScsiDiskDevice->BlkIo.Reset       = ScsiDiskReset;
  ScsiDiskDevice->BlkIo.ReadBlocks  = ScsiDiskReadBlocks;
  ScsiDiskDevice->BlkIo.WriteBlocks = ScsiDiskWriteBlocks;
  ScsiDiskDevice->BlkIo.FlushBlocks = ScsiDiskFlushBlocks;
  ScsiDiskDevice->Handle            = Controller;

  ScsiIo->GetDeviceType (ScsiIo, &(ScsiDiskDevice->DeviceType));
  switch (ScsiDiskDevice->DeviceType) {
  case EFI_SCSI_TYPE_DISK:
    ScsiDiskDevice->BlkIo.Media->BlockSize = 0x200;
    break;

  case EFI_SCSI_TYPE_CDROM:
    ScsiDiskDevice->BlkIo.Media->BlockSize = 0x800;
    break;
  }
  //
  // The Sense Data Array's initial size is 6
  //
  ScsiDiskDevice->SenseDataNumber = 6;
  Status = gBS->AllocatePool (
                  EfiBootServicesData,
                  sizeof (EFI_SCSI_SENSE_DATA) * ScsiDiskDevice->SenseDataNumber,
                  (VOID **) &(ScsiDiskDevice->SenseData)
                  );
  if (EFI_ERROR (Status)) {
    gBS->CloseProtocol (
          Controller,
          &gEfiScsiIoProtocolGuid,
          This->DriverBindingHandle,
          Controller
          );
    gBS->FreePool (ScsiDiskDevice);
    return Status;
  }

  ZeroMem (
    ScsiDiskDevice->SenseData,
    sizeof (EFI_SCSI_SENSE_DATA) * ScsiDiskDevice->SenseDataNumber
    );

  //
  // Retrive device information
  //
  MaxRetry = 2;
  for (Index = 0; Index < MaxRetry; Index++) {
    Status = ScsiDiskInquiryDevice (ScsiDiskDevice, &NeedRetry);
    if (!EFI_ERROR (Status)) {
      break;
    }

    if (!NeedRetry) {
      gBS->FreePool (ScsiDiskDevice->SenseData);
      gBS->CloseProtocol (
             Controller,
             &gEfiScsiIoProtocolGuid,
             This->DriverBindingHandle,
             Controller
             );
      gBS->FreePool (ScsiDiskDevice);
      return EFI_DEVICE_ERROR;
    }
  }
  //
  // The second parameter "TRUE" means must
  // retrieve media capacity
  //
  Status = ScsiDiskDetectMedia (ScsiDiskDevice, TRUE, &Temp);
  if (!EFI_ERROR (Status)) {
    Status = gBS->InstallMultipleProtocolInterfaces (
                    &Controller,
                    &gEfiBlockIoProtocolGuid,
                    &ScsiDiskDevice->BlkIo,
                    NULL
                    );
  }

  if (EFI_ERROR (Status)) {
    gBS->FreePool (ScsiDiskDevice->SenseData);
    gBS->CloseProtocol (
           Controller,
           &gEfiScsiIoProtocolGuid,
           This->DriverBindingHandle,
           Controller
           );
    gBS->FreePool (ScsiDiskDevice);
    return Status;
  }

  ScsiDiskDevice->ControllerNameTable = NULL;
  AddUnicodeString2 (
    "eng",
    gScsiDiskComponentName.SupportedLanguages,
    &ScsiDiskDevice->ControllerNameTable,
    L"SCSI Disk Device",
    TRUE
    );
  AddUnicodeString2 (
    "en",
    gScsiDiskComponentName2.SupportedLanguages,
    &ScsiDiskDevice->ControllerNameTable,
    L"SCSI Disk Device",
    FALSE
    );


  return EFI_SUCCESS;

}

EFI_STATUS
EFIAPI
ScsiDiskDriverBindingStop (
  IN  EFI_DRIVER_BINDING_PROTOCOL     *This,
  IN  EFI_HANDLE                      Controller,
  IN  UINTN                           NumberOfChildren,
  IN  EFI_HANDLE                      *ChildHandleBuffer
  )
/*++

Routine Description:

    Stop this driver on ControllerHandle. Support stoping any child handles
    created by this driver.

Arguments:

    This              - Protocol instance pointer.
    Controller        - Handle of device to stop driver on
    NumberOfChildren  - Number of Children in the ChildHandleBuffer
    ChildHandleBuffer - List of handles for the children we need to stop.

Returns:

    EFI_SUCCESS
    EFI_DEVICE_ERROR
    others
  
--*/
{
  EFI_BLOCK_IO_PROTOCOL *BlkIo;
  SCSI_DISK_DEV         *ScsiDiskDevice;
  EFI_STATUS            Status;

  Status = gBS->OpenProtocol (
                  Controller,
                  &gEfiBlockIoProtocolGuid,
                  (VOID **) &BlkIo,
                  This->DriverBindingHandle,
                  Controller,
                  EFI_OPEN_PROTOCOL_GET_PROTOCOL
                  );
  if (EFI_ERROR (Status)) {
    return Status;
  }

  ScsiDiskDevice = SCSI_DISK_DEV_FROM_THIS (BlkIo);
  Status = gBS->UninstallProtocolInterface (
                  Controller,
                  &gEfiBlockIoProtocolGuid,
                  &ScsiDiskDevice->BlkIo
                  );
  if (!EFI_ERROR (Status)) {
    gBS->CloseProtocol (
           Controller,
           &gEfiScsiIoProtocolGuid,
           This->DriverBindingHandle,
           Controller
           );

    ReleaseScsiDiskDeviceResources (ScsiDiskDevice);

    return EFI_SUCCESS;
  }
  //
  // errors met
  //
  return Status;
}


EFI_STATUS
EFIAPI
ScsiDiskReset (
  IN  EFI_BLOCK_IO_PROTOCOL   *This,
  IN  BOOLEAN                 ExtendedVerification
  )
/*++

Routine Description:

  Reset SCSI Disk  

Arguments:

  This                  - The pointer of EFI_BLOCK_IO_PROTOCOL
  ExtendedVerification  - The flag about if extend verificate

Returns:

  EFI_STATUS

--*/
{
  EFI_TPL       OldTpl;
  SCSI_DISK_DEV *ScsiDiskDevice;
  EFI_STATUS    Status;

  OldTpl = gBS->RaiseTPL (TPL_CALLBACK);

  ScsiDiskDevice  = SCSI_DISK_DEV_FROM_THIS (This);

  Status          = ScsiDiskDevice->ScsiIo->ResetDevice (ScsiDiskDevice->ScsiIo);

  if (!ExtendedVerification) {
    goto Done;
  }

  Status = ScsiDiskDevice->ScsiIo->ResetBus (ScsiDiskDevice->ScsiIo);

Done:
  gBS->RestoreTPL (OldTpl);
  return Status;
}

EFI_STATUS
EFIAPI
ScsiDiskReadBlocks (
  IN  EFI_BLOCK_IO_PROTOCOL   *This,
  IN  UINT32                  MediaId,
  IN  EFI_LBA                 LBA,
  IN  UINTN                   BufferSize,
  OUT VOID                    *Buffer
  )
/*++

Routine Description:

  The function is to Read Block from SCSI Disk

Arguments:

  This        - The pointer of EFI_BLOCK_IO_PROTOCOL
  MediaId     - The Id of Media detected
  LBA         - The logic block address
  BufferSize  - The size of Buffer
  Buffer      - The buffer to fill the read out data

Returns:

  EFI_INVALID_PARAMETER - Invalid parameter passed in.
  EFI_SUCCESS           - Successfully to read out block.
  EFI_DEVICE_ERROR      - Fail to detect media.
  EFI_NO_MEDIA          - Media is not present.
  EFI_MEDIA_CHANGED     - Media has changed.
  EFI_BAD_BUFFER_SIZE   - The buffer size is not multiple of BlockSize.

--*/
{
  SCSI_DISK_DEV       *ScsiDiskDevice;
  EFI_BLOCK_IO_MEDIA  *Media;
  EFI_STATUS          Status;
  UINTN               BlockSize;
  UINTN               NumberOfBlocks;
  BOOLEAN             MediaChange;
  EFI_TPL             OldTpl;

  MediaChange = FALSE;
  if (!Buffer) {
    return EFI_INVALID_PARAMETER;
  }

  if (BufferSize == 0) {
    return EFI_SUCCESS;
  }

  OldTpl = gBS->RaiseTPL (TPL_CALLBACK);

  ScsiDiskDevice = SCSI_DISK_DEV_FROM_THIS (This);

  if (!IsDeviceFixed (ScsiDiskDevice)) {

    Status = ScsiDiskDetectMedia (ScsiDiskDevice, FALSE, &MediaChange);
    if (EFI_ERROR (Status)) {
      Status = EFI_DEVICE_ERROR;
      goto Done;
    }

    if (MediaChange) {
      gBS->ReinstallProtocolInterface (
            ScsiDiskDevice->Handle,
            &gEfiBlockIoProtocolGuid,
            &ScsiDiskDevice->BlkIo,
            &ScsiDiskDevice->BlkIo
            );
    }
  }
  //
  // Get the intrinsic block size
  //
  Media           = ScsiDiskDevice->BlkIo.Media;
  BlockSize       = Media->BlockSize;

  NumberOfBlocks  = BufferSize / BlockSize;

  if (!(Media->MediaPresent)) {
    Status = EFI_NO_MEDIA;
    goto Done;
  }

  if (MediaId != Media->MediaId) {
    Status = EFI_MEDIA_CHANGED;
    goto Done;
  }

  if (BufferSize % BlockSize != 0) {
    Status = EFI_BAD_BUFFER_SIZE;
    goto Done;
  }

  if (LBA > Media->LastBlock) {
    Status = EFI_INVALID_PARAMETER;
    goto Done;
  }

  if ((LBA + NumberOfBlocks - 1) > Media->LastBlock) {
    Status = EFI_INVALID_PARAMETER;
    goto Done;
  }

  if ((Media->IoAlign > 1) && (((UINTN) Buffer & (Media->IoAlign - 1)) != 0)) {
    Status = EFI_INVALID_PARAMETER;
    goto Done;
  }

  //
  // If all the parameters are valid, then perform read sectors command
  // to transfer data from device to host.
  //
  Status = ScsiDiskReadSectors (ScsiDiskDevice, Buffer, LBA, NumberOfBlocks);

Done:
  gBS->RestoreTPL (OldTpl);
  return Status;
}

EFI_STATUS
EFIAPI
ScsiDiskWriteBlocks (
  IN  EFI_BLOCK_IO_PROTOCOL   *This,
  IN  UINT32                  MediaId,
  IN  EFI_LBA                 LBA,
  IN  UINTN                   BufferSize,
  IN  VOID                    *Buffer
  )
/*++

Routine Description:

  The function is to Write Block to SCSI Disk

Arguments:

  This        - The pointer of EFI_BLOCK_IO_PROTOCOL
  MediaId     - The Id of Media detected
  LBA         - The logic block address
  BufferSize  - The size of Buffer
  Buffer      - The buffer to fill the read out data

Returns:

  EFI_INVALID_PARAMETER - Invalid parameter passed in.
  EFI_SUCCESS           - Successfully to read out block.
  EFI_DEVICE_ERROR      - Fail to detect media.
  EFI_NO_MEDIA          - Media is not present.
  EFI_MEDIA_CHANGED     - Media has changed.
  EFI_BAD_BUFFER_SIZE   - The buffer size is not multiple of BlockSize.

--*/
{
  SCSI_DISK_DEV       *ScsiDiskDevice;
  EFI_BLOCK_IO_MEDIA  *Media;
  EFI_STATUS          Status;
  UINTN               BlockSize;
  UINTN               NumberOfBlocks;
  BOOLEAN             MediaChange;
  EFI_TPL             OldTpl;

  MediaChange = FALSE;
  if (!Buffer) {
    return EFI_INVALID_PARAMETER;
  }

  if (BufferSize == 0) {
    return EFI_SUCCESS;
  }

  OldTpl = gBS->RaiseTPL (TPL_CALLBACK);

  ScsiDiskDevice = SCSI_DISK_DEV_FROM_THIS (This);

  if (!IsDeviceFixed (ScsiDiskDevice)) {

    Status = ScsiDiskDetectMedia (ScsiDiskDevice, FALSE, &MediaChange);
    if (EFI_ERROR (Status)) {
      Status = EFI_DEVICE_ERROR;
      goto Done;
    }

    if (MediaChange) {
      gBS->ReinstallProtocolInterface (
            ScsiDiskDevice->Handle,
            &gEfiBlockIoProtocolGuid,
            &ScsiDiskDevice->BlkIo,
            &ScsiDiskDevice->BlkIo
            );
    }
  }
  //
  // Get the intrinsic block size
  //
  Media           = ScsiDiskDevice->BlkIo.Media;
  BlockSize       = Media->BlockSize;

  NumberOfBlocks  = BufferSize / BlockSize;

  if (!(Media->MediaPresent)) {
    Status = EFI_NO_MEDIA;
    goto Done;
  }

  if (MediaId != Media->MediaId) {
    Status = EFI_MEDIA_CHANGED;
    goto Done;
  }

  if (BufferSize % BlockSize != 0) {
    Status = EFI_BAD_BUFFER_SIZE;
    goto Done;
  }

  if (LBA > Media->LastBlock) {
    Status = EFI_INVALID_PARAMETER;
    goto Done;
  }

  if ((LBA + NumberOfBlocks - 1) > Media->LastBlock) {
    Status = EFI_INVALID_PARAMETER;
    goto Done;
  }

  if ((Media->IoAlign > 1) && (((UINTN) Buffer & (Media->IoAlign - 1)) != 0)) {
    Status = EFI_INVALID_PARAMETER;
    goto Done;
  }
  //
  // if all the parameters are valid, then perform read sectors command
  // to transfer data from device to host.
  //
  Status = ScsiDiskWriteSectors (ScsiDiskDevice, Buffer, LBA, NumberOfBlocks);

Done:
  gBS->RestoreTPL (OldTpl);
  return Status;
}

EFI_STATUS
EFIAPI
ScsiDiskFlushBlocks (
  IN  EFI_BLOCK_IO_PROTOCOL   *This
  )
/*++

Routine Description:

  Flush Block to Disk

Arguments:

  This  - The pointer of EFI_BLOCK_IO_PROTOCOL

Returns:

  EFI_SUCCESS 

--*/
{
  //
  // return directly
  //
  return EFI_SUCCESS;
}

EFI_STATUS
ScsiDiskDetectMedia (
  SCSI_DISK_DEV   *ScsiDiskDevice,
  BOOLEAN         MustReadCapacity,
  BOOLEAN         *MediaChange
  )
/*++

Routine Description:

  Dectect Device and read out capacity ,if error occurs, parse the sense key.

Arguments:

  ScsiDiskDevice     - The pointer of SCSI_DISK_DEV
  MustReadCapacity   - The flag about reading device capacity
  MediaChange        - The pointer of flag indicates if media has changed 

Returns:

  EFI_DEVICE_ERROR   - Indicates that error occurs
  EFI_SUCCESS        - Successfully to detect media

--*/
{
  EFI_STATUS          Status;
  EFI_STATUS          ReadCapacityStatus;
  EFI_SCSI_SENSE_DATA *SenseData;
  UINTN               NumberOfSenseKeys;
  BOOLEAN             NeedRetry;
  BOOLEAN             NeedReadCapacity;
  UINT8               Index;
  UINT8               MaxRetry;
  EFI_BLOCK_IO_MEDIA  OldMedia;
  UINTN               Action;

  Status              = EFI_SUCCESS;
  ReadCapacityStatus  = EFI_SUCCESS;
  SenseData           = NULL;
  NumberOfSenseKeys   = 0;
  NeedReadCapacity    = FALSE;
  CopyMem (&OldMedia, ScsiDiskDevice->BlkIo.Media, sizeof (OldMedia));
  *MediaChange        = FALSE;
  MaxRetry            = 3;

  for (Index = 0; Index < MaxRetry; Index++) {
    Status = ScsiDiskTestUnitReady (
              ScsiDiskDevice,
              &NeedRetry,
              &SenseData,
              &NumberOfSenseKeys
              );
    if (!EFI_ERROR (Status)) {
      break;
    }

    if (!NeedRetry) {
      return Status;
    }
  }

  if ((Index == MaxRetry) && EFI_ERROR (Status)) {
    return EFI_DEVICE_ERROR;
  }

  Status = DetectMediaParsingSenseKeys (
            ScsiDiskDevice,
            SenseData,
            NumberOfSenseKeys,
            &Action
            );
  if (EFI_ERROR (Status)) {
    return Status;
  }
  //
  // ACTION_NO_ACTION: need not read capacity
  // other action code: need read capacity
  //
  if (Action == ACTION_NO_ACTION) {
    NeedReadCapacity = FALSE;
  } else {
    NeedReadCapacity = TRUE;
  }

  //
  // either NeedReadCapacity is TRUE, or MustReadCapacity is TRUE,
  // retrieve capacity via Read Capacity command
  //
  if (NeedReadCapacity || MustReadCapacity) {
    //
    // retrieve media information
    //
    MaxRetry = 3;
    for (Index = 0; Index < MaxRetry; Index++) {

      ReadCapacityStatus = ScsiDiskReadCapacity (
                            ScsiDiskDevice,
                            &NeedRetry,
                            &SenseData,
                            &NumberOfSenseKeys
                            );
      if (EFI_ERROR (ReadCapacityStatus) && !NeedRetry) {
        return EFI_DEVICE_ERROR;
      }
      //
      // analyze sense key to action
      //
      Status = DetectMediaParsingSenseKeys (
                ScsiDiskDevice,
                SenseData,
                NumberOfSenseKeys,
                &Action
                );
      //
      // if Status is error, it may indicate crisis error,
      // so return without retry.
      //
      if (EFI_ERROR (Status)) {
        return Status;
      }

      switch (Action) {
      case ACTION_NO_ACTION:
        //
        // no retry
        //
        Index = MaxRetry;
        break;

      case ACTION_RETRY_COMMAND_LATER:
        //
        // retry the ReadCapacity later and continuously, until the condition
        // no longer emerges.
        // stall time is 100000us, or say 0.1 second.
        //
        gBS->Stall (100000);
        Index = 0;
        break;

      default:
        //
        // other cases, just retry the command
        //
        break;
      }
    }

    if ((Index == MaxRetry) && EFI_ERROR (ReadCapacityStatus)) {
      return EFI_DEVICE_ERROR;
    }
  }

  if (ScsiDiskDevice->BlkIo.Media->MediaId != OldMedia.MediaId) {
    //
    // Media change information got from the device
    //
    *MediaChange = TRUE;
  }

  if (ScsiDiskDevice->BlkIo.Media->ReadOnly != OldMedia.ReadOnly) {
    *MediaChange = TRUE;
    ScsiDiskDevice->BlkIo.Media->MediaId += 1;
  }

  if (ScsiDiskDevice->BlkIo.Media->BlockSize != OldMedia.BlockSize) {
    *MediaChange = TRUE;
    ScsiDiskDevice->BlkIo.Media->MediaId += 1;
  }

  if (ScsiDiskDevice->BlkIo.Media->LastBlock != OldMedia.LastBlock) {
    *MediaChange = TRUE;
    ScsiDiskDevice->BlkIo.Media->MediaId += 1;
  }

  if (ScsiDiskDevice->BlkIo.Media->MediaPresent != OldMedia.MediaPresent) {
    if (ScsiDiskDevice->BlkIo.Media->MediaPresent) {
      //
      // when change from no media to media present, reset the MediaId to 1.
      //
      ScsiDiskDevice->BlkIo.Media->MediaId = 1;
    } else {
      //
      // when no media, reset the MediaId to zero.
      //
      ScsiDiskDevice->BlkIo.Media->MediaId = 0;
    }

    *MediaChange = TRUE;
  }

  return EFI_SUCCESS;
}

EFI_STATUS
ScsiDiskInquiryDevice (
  SCSI_DISK_DEV   *ScsiDiskDevice,
  BOOLEAN         *NeedRetry
  )
/*++

Routine Description:

  Send out Inquiry command to Device

Arguments:

  ScsiDiskDevice  - The pointer of SCSI_DISK_DEV
  NeedRetry       - Indicates if needs try again when error happens

Returns:

  EFI_DEVICE_ERROR   - Indicates that error occurs
  EFI_SUCCESS        - Successfully to detect media

--*/
{
  UINT32              InquiryDataLength;
  UINT8               SenseDataLength;
  UINT8               HostAdapterStatus;
  UINT8               TargetStatus;
  EFI_SCSI_SENSE_DATA *SenseDataArray;
  UINTN               NumberOfSenseKeys;
  EFI_STATUS          Status;
  UINT8               MaxRetry;
  UINT8               Index;

  InquiryDataLength = sizeof (EFI_SCSI_INQUIRY_DATA);
  SenseDataLength   = 0;

  Status = ScsiInquiryCommand (
            ScsiDiskDevice->ScsiIo,
            EfiScsiStallSeconds (1),
            NULL,
            &SenseDataLength,
            &HostAdapterStatus,
            &TargetStatus,
            (VOID *) &(ScsiDiskDevice->InquiryData),
            &InquiryDataLength,
            FALSE
            );
    //
    // no need to check HostAdapterStatus and TargetStatus
    //
  if ((Status == EFI_SUCCESS) || (Status == EFI_WARN_BUFFER_TOO_SMALL)) {
     ParseInquiryData (ScsiDiskDevice);
     return EFI_SUCCESS;
 
   } else if (Status == EFI_NOT_READY) {
     *NeedRetry = TRUE;
     return EFI_DEVICE_ERROR;
 
   } else if ((Status == EFI_INVALID_PARAMETER) || (Status == EFI_UNSUPPORTED)) {
     *NeedRetry = FALSE;
     return EFI_DEVICE_ERROR;
   }
   //
   // go ahead to check HostAdapterStatus and TargetStatus
   // (EFI_TIMEOUT, EFI_DEVICE_ERROR)
   //
 
   Status = CheckHostAdapterStatus (HostAdapterStatus);
   if ((Status == EFI_TIMEOUT) || (Status == EFI_NOT_READY)) {
     *NeedRetry = TRUE;
     return EFI_DEVICE_ERROR;
   } else if (Status == EFI_DEVICE_ERROR) {
      //
      // reset the scsi channel
      //
    ScsiDiskDevice->ScsiIo->ResetBus (ScsiDiskDevice->ScsiIo);
    *NeedRetry = FALSE;
    return EFI_DEVICE_ERROR;
  }

  Status = CheckTargetStatus (TargetStatus);
  if (Status == EFI_NOT_READY) {
    //
    // reset the scsi device
    //
    ScsiDiskDevice->ScsiIo->ResetDevice (ScsiDiskDevice->ScsiIo);
    *NeedRetry = TRUE;
    return EFI_DEVICE_ERROR;

  } else if (Status == EFI_DEVICE_ERROR) {
    *NeedRetry = FALSE;
    return EFI_DEVICE_ERROR;
  }
  
  //
  // if goes here, meant SubmitInquiryCommand() failed.
  // if ScsiDiskRequestSenseKeys() succeeds at last,
  // better retry SubmitInquiryCommand(). (by setting *NeedRetry = TRUE)
  //
  MaxRetry = 3;
  for (Index = 0; Index < MaxRetry; Index++) {
    Status = ScsiDiskRequestSenseKeys (
              ScsiDiskDevice,
              NeedRetry,
              &SenseDataArray,
              &NumberOfSenseKeys,
              TRUE
              );
    if (!EFI_ERROR (Status)) {
      *NeedRetry = TRUE;
      return EFI_DEVICE_ERROR;
    }

    if (!*NeedRetry) {
      return EFI_DEVICE_ERROR;
    }
  }
  //
  // ScsiDiskRequestSenseKeys() failed after several rounds of retry.
  // set *NeedRetry = FALSE to avoid the outside caller try again.
  //
  *NeedRetry = FALSE;
  return EFI_DEVICE_ERROR;
}

EFI_STATUS
ScsiDiskTestUnitReady (
  SCSI_DISK_DEV         *ScsiDiskDevice,
  BOOLEAN               *NeedRetry,
  EFI_SCSI_SENSE_DATA   **SenseDataArray,
  UINTN                 *NumberOfSenseKeys
  )
 /*++

Routine Description:

  When Test Unit Ready command succeeds, retrieve Sense Keys via Request Sense;
  When Test Unit Ready command encounters any error caused by host adapter or
  target, return error without retrieving Sense Keys.
  
Arguments:

  ScsiDiskDevice  - The pointer of SCSI_DISK_DEV
  NeedRetry       - The pointer of flag indicates try again
  SenseDataArray  - The pointer of an array of sense data
  NumberOfSenseKeys - The pointer of the number of sense data array
  
Returns:

  EFI_DEVICE_ERROR   - Indicates that error occurs
  EFI_SUCCESS        - Successfully to test unit

--*/
{
  EFI_STATUS  Status;
  UINT8       SenseDataLength;
  UINT8       HostAdapterStatus;
  UINT8       TargetStatus;
  UINT8       Index;
  UINT8       MaxRetry;

  SenseDataLength     = 0;
  *NumberOfSenseKeys  = 0;

  //
  // Parameter 3 and 4: do not require sense data, retrieve it when needed.
  //
  Status = ScsiTestUnitReadyCommand (
            ScsiDiskDevice->ScsiIo,
            EfiScsiStallSeconds (1),
            NULL,
            &SenseDataLength,
            &HostAdapterStatus,
            &TargetStatus
            );
  //
  // no need to check HostAdapterStatus and TargetStatus
  //
  if (Status == EFI_NOT_READY) {
    *NeedRetry = TRUE;
    return EFI_DEVICE_ERROR;

  } else if ((Status == EFI_INVALID_PARAMETER) || (Status == EFI_UNSUPPORTED)) {
    *NeedRetry = FALSE;
    return EFI_DEVICE_ERROR;
  }
  //
  // go ahead to check HostAdapterStatus and TargetStatus(in case of EFI_DEVICE_ERROR)
  //

  Status = CheckHostAdapterStatus (HostAdapterStatus);
  if ((Status == EFI_TIMEOUT) || (Status == EFI_NOT_READY)) {
    *NeedRetry = TRUE;
    return EFI_DEVICE_ERROR;

  } else if (Status == EFI_DEVICE_ERROR) {
    //
    // reset the scsi channel
    //
    ScsiDiskDevice->ScsiIo->ResetBus (ScsiDiskDevice->ScsiIo);
    *NeedRetry = FALSE;
    return EFI_DEVICE_ERROR;
  }

  Status = CheckTargetStatus (TargetStatus);
  if (Status == EFI_NOT_READY) {
    //
    // reset the scsi device
    //
    ScsiDiskDevice->ScsiIo->ResetDevice (ScsiDiskDevice->ScsiIo);
    *NeedRetry = TRUE;
    return EFI_DEVICE_ERROR;

  } else if (Status == EFI_DEVICE_ERROR) {
    *NeedRetry = FALSE;
    return EFI_DEVICE_ERROR;
  }

  MaxRetry = 3;
  for (Index = 0; Index < MaxRetry; Index++) {
    Status = ScsiDiskRequestSenseKeys (
              ScsiDiskDevice,
              NeedRetry,
              SenseDataArray,
              NumberOfSenseKeys,
              FALSE
              );
    if (!EFI_ERROR (Status)) {
      return EFI_SUCCESS;
    }

    if (!*NeedRetry) {
      return EFI_DEVICE_ERROR;
    }
  }
  //
  // ScsiDiskRequestSenseKeys() failed after several rounds of retry.
  // set *NeedRetry = FALSE to avoid the outside caller try again.
  //
  *NeedRetry = FALSE;
  return EFI_DEVICE_ERROR;
}

EFI_STATUS
DetectMediaParsingSenseKeys (
  SCSI_DISK_DEV           *ScsiDiskDevice,
  EFI_SCSI_SENSE_DATA     *SenseData,
  UINTN                   NumberOfSenseKeys,
  UINTN                   *Action
  )
/*++

Routine Description:

  Parsing Sense Keys which got from request sense command.
  
Arguments:

  ScsiDiskDevice    - The pointer of SCSI_DISK_DEV
  SenseData         - The pointer of EFI_SCSI_SENSE_DATA
  NumberOfSenseKeys - The number of sense key  
  Action            - The pointer of action which indicates what is need to do next

Returns:

  EFI_DEVICE_ERROR   - Indicates that error occurs
  EFI_SUCCESS        - Successfully to complete the parsing

--*/
{
  BOOLEAN RetryLater;

  //
  // Default is to read capacity, unless..
  //
  *Action = ACTION_READ_CAPACITY;

  if (NumberOfSenseKeys == 0) {
    *Action = ACTION_NO_ACTION;
    return EFI_SUCCESS;
  }

  if (!ScsiDiskHaveSenseKey (SenseData, NumberOfSenseKeys)) {
    //
    // No Sense Key returned from last submitted command
    //
    *Action = ACTION_NO_ACTION;
    return EFI_SUCCESS;
  }

  if (ScsiDiskIsNoMedia (SenseData, NumberOfSenseKeys)) {
    ScsiDiskDevice->BlkIo.Media->MediaPresent = FALSE;
    ScsiDiskDevice->BlkIo.Media->LastBlock    = 0;
    *Action = ACTION_NO_ACTION;
    return EFI_SUCCESS;
  }

  if (ScsiDiskIsMediaChange (SenseData, NumberOfSenseKeys)) {
    ScsiDiskDevice->BlkIo.Media->MediaId++;
    return EFI_SUCCESS;
  }

  if (ScsiDiskIsMediaError (SenseData, NumberOfSenseKeys)) {
    ScsiDiskDevice->BlkIo.Media->MediaPresent = FALSE;
    ScsiDiskDevice->BlkIo.Media->LastBlock    = 0;
    return EFI_DEVICE_ERROR;
  }

  if (ScsiDiskIsHardwareError (SenseData, NumberOfSenseKeys)) {
    return EFI_DEVICE_ERROR;
  }

  if (!ScsiDiskIsDriveReady (SenseData, NumberOfSenseKeys, &RetryLater)) {
    if (RetryLater) {
      *Action = ACTION_RETRY_COMMAND_LATER;
      return EFI_SUCCESS;
    }

    return EFI_DEVICE_ERROR;
  }

  return EFI_SUCCESS;
}

EFI_STATUS
ScsiDiskReadCapacity (
  SCSI_DISK_DEV           *ScsiDiskDevice,
  BOOLEAN                 *NeedRetry,
  EFI_SCSI_SENSE_DATA     **SenseDataArray,
  UINTN                   *NumberOfSenseKeys
  )
/*++

Routine Description:

  Send read capacity command to device and get the device parameter

Arguments:

  ScsiDiskDevice     -  The pointer of SCSI_DISK_DEV
  NeedRetry          -  The pointer of flag indicates if need a retry
  SenseDataArray     -  The pointer of an array of sense data
  NumberOfSenseKeys  -  The number of sense key

Returns:

  EFI_DEVICE_ERROR   - Indicates that error occurs
  EFI_SUCCESS        - Successfully to read capacity

--*/
{
  EFI_SCSI_DISK_CAPACITY_DATA CapacityData;
  UINT32                      DataLength;
  UINT8                       HostAdapterStatus;
  UINT8                       TargetStatus;
  EFI_STATUS                  CommandStatus;
  EFI_STATUS                  Status;
  UINT8                       Index;
  UINT8                       MaxRetry;
  UINT8                       SenseDataLength;

  SenseDataLength = 0;
  ZeroMem (&CapacityData, sizeof (EFI_SCSI_DISK_CAPACITY_DATA));
  DataLength          = sizeof (EFI_SCSI_DISK_CAPACITY_DATA);

  *NumberOfSenseKeys  = 0;
  *NeedRetry          = FALSE;
  //
  // submit Read Capacity Command. in this call,not request sense data
  //
  CommandStatus = ScsiReadCapacityCommand (
                    ScsiDiskDevice->ScsiIo,
                    EfiScsiStallSeconds (1),
                    NULL,
                    &SenseDataLength,
                    &HostAdapterStatus,
                    &TargetStatus,
                    (VOID *) &CapacityData,
                    &DataLength,
                    FALSE
                    );
  //
    // no need to check HostAdapterStatus and TargetStatus
    //
   if (CommandStatus == EFI_SUCCESS) {
     GetMediaInfo (ScsiDiskDevice, &CapacityData);
     return EFI_SUCCESS;
 
   } else if (CommandStatus == EFI_NOT_READY) {
     *NeedRetry = TRUE;
     return EFI_DEVICE_ERROR;
 
   } else if ((CommandStatus == EFI_INVALID_PARAMETER) || (CommandStatus == EFI_UNSUPPORTED)) {
     *NeedRetry = FALSE;
     return EFI_DEVICE_ERROR;
   }
   //
   // go ahead to check HostAdapterStatus and TargetStatus
   // (EFI_TIMEOUT, EFI_DEVICE_ERROR, EFI_WARN_BUFFER_TOO_SMALL)
   //
 
   Status = CheckHostAdapterStatus (HostAdapterStatus);
   if ((Status == EFI_TIMEOUT) || (Status == EFI_NOT_READY)) {
     *NeedRetry = TRUE;
     return EFI_DEVICE_ERROR;
 
   } else if (Status == EFI_DEVICE_ERROR) {
    //
    // reset the scsi channel
    //
    ScsiDiskDevice->ScsiIo->ResetBus (ScsiDiskDevice->ScsiIo);
    *NeedRetry = FALSE;
    return EFI_DEVICE_ERROR;
  }

  Status = CheckTargetStatus (TargetStatus);
  if (Status == EFI_NOT_READY) {
    //
    // reset the scsi device
    //
    ScsiDiskDevice->ScsiIo->ResetDevice (ScsiDiskDevice->ScsiIo);
    *NeedRetry = TRUE;
    return EFI_DEVICE_ERROR;

  } else if (Status == EFI_DEVICE_ERROR) {
    *NeedRetry = FALSE;
    return EFI_DEVICE_ERROR;
  }
  
  //
  // if goes here, meant SubmitReadCapacityCommand() failed.
  // if ScsiDiskRequestSenseKeys() succeeds at last,
  // better retry SubmitReadCapacityCommand(). (by setting *NeedRetry = TRUE)
  //
  MaxRetry = 3;
  for (Index = 0; Index < MaxRetry; Index++) {

    Status = ScsiDiskRequestSenseKeys (
              ScsiDiskDevice,
              NeedRetry,
              SenseDataArray,
              NumberOfSenseKeys,
              TRUE
              );
    if (!EFI_ERROR (Status)) {
      *NeedRetry = TRUE;
      return EFI_DEVICE_ERROR;
    }

    if (!*NeedRetry) {
      return EFI_DEVICE_ERROR;
    }
  }
  //
  // ScsiDiskRequestSenseKeys() failed after several rounds of retry.
  // set *NeedRetry = FALSE to avoid the outside caller try again.
  //
  *NeedRetry = FALSE;
  return EFI_DEVICE_ERROR;
}

EFI_STATUS
CheckHostAdapterStatus (
  UINT8   HostAdapterStatus
  )
/*++

Routine Description:

  Check the HostAdapter status
  
Arguments:

  HostAdapterStatus - Host Adapter status

Returns:

  EFI_SUCCESS       
  EFI_TIMEOUT       
  EFI_NOT_READY     
  EFI_DEVICE_ERROR  

--*/
{
  switch (HostAdapterStatus) {
  case EFI_EXT_SCSI_STATUS_HOST_ADAPTER_OK:
    return EFI_SUCCESS;

  case EFI_EXT_SCSI_STATUS_HOST_ADAPTER_SELECTION_TIMEOUT:
  case EFI_EXT_SCSI_STATUS_HOST_ADAPTER_TIMEOUT:
  case EFI_EXT_SCSI_STATUS_HOST_ADAPTER_TIMEOUT_COMMAND:
    return EFI_TIMEOUT;

  case EFI_EXT_SCSI_STATUS_HOST_ADAPTER_MESSAGE_REJECT:
  case EFI_EXT_SCSI_STATUS_HOST_ADAPTER_PARITY_ERROR:
  case EFI_EXT_SCSI_STATUS_HOST_ADAPTER_REQUEST_SENSE_FAILED:
  case EFI_EXT_SCSI_STATUS_HOST_ADAPTER_DATA_OVERRUN_UNDERRUN:
  case EFI_EXT_SCSI_STATUS_HOST_ADAPTER_BUS_RESET:
    return EFI_NOT_READY;

  case EFI_EXT_SCSI_STATUS_HOST_ADAPTER_BUS_FREE:
  case EFI_EXT_SCSI_STATUS_HOST_ADAPTER_PHASE_ERROR:
    return EFI_DEVICE_ERROR;

  default:
    return EFI_SUCCESS;
  }
}

EFI_STATUS
CheckTargetStatus (
  UINT8   TargetStatus
  )
/*++

Routine Description:

  Check the target status
  
Arguments:

  TargetStatus  - Target status

Returns:

  EFI_NOT_READY  
  EFI_DEVICE_ERROR 
  EFI_SUCCESS

--*/
{
  switch (TargetStatus) {
  case EFI_EXT_SCSI_STATUS_TARGET_GOOD:
  case EFI_EXT_SCSI_STATUS_TARGET_CHECK_CONDITION:
  case EFI_EXT_SCSI_STATUS_TARGET_CONDITION_MET:
    return EFI_SUCCESS;

  case EFI_EXT_SCSI_STATUS_TARGET_INTERMEDIATE:
  case EFI_EXT_SCSI_STATUS_TARGET_INTERMEDIATE_CONDITION_MET:
  case EFI_EXT_SCSI_STATUS_TARGET_BUSY:
  case EFI_EXT_SCSI_STATUS_TARGET_TASK_SET_FULL:
    return EFI_NOT_READY;

  case EFI_EXT_SCSI_STATUS_TARGET_RESERVATION_CONFLICT:
    return EFI_DEVICE_ERROR;
    break;

  default:
    return EFI_SUCCESS;
  }
}

EFI_STATUS
ScsiDiskRequestSenseKeys (
  SCSI_DISK_DEV           *ScsiDiskDevice,
  BOOLEAN                 *NeedRetry,
  EFI_SCSI_SENSE_DATA     **SenseDataArray,
  UINTN                   *NumberOfSenseKeys,
  BOOLEAN                 AskResetIfError
  )
/*++

Routine Description:

  Retrieve all sense keys from the device.
  When encountering error during the process,
  if retrieve sense keys before error encounterred,
  return the sense keys with return status set to EFI_SUCCESS,
  and NeedRetry set to FALSE; otherwize, return the proper return
  status.

Arguments:

  ScsiDiskDevice     -  The pointer of SCSI_DISK_DEV
  NeedRetry          -  The pointer of flag indicates if need a retry
  SenseDataArray     -  The pointer of an array of sense data
  NumberOfSenseKeys  -  The number of sense key
  AskResetIfError    -  The flag indicates if need reset when error occurs
  
Returns:

  EFI_DEVICE_ERROR   - Indicates that error occurs
  EFI_SUCCESS        - Successfully to request sense key

--*/
{
  EFI_SCSI_SENSE_DATA *PtrSenseData;
  UINT8               SenseDataLength;
  BOOLEAN             SenseReq;
  EFI_STATUS          Status;
  EFI_STATUS          FallStatus;
  UINT8               HostAdapterStatus;
  UINT8               TargetStatus;

  FallStatus      = EFI_SUCCESS;
  SenseDataLength = sizeof (EFI_SCSI_SENSE_DATA);

  ZeroMem (
    ScsiDiskDevice->SenseData,
    sizeof (EFI_SCSI_SENSE_DATA) * (ScsiDiskDevice->SenseDataNumber)
    );

  *NumberOfSenseKeys  = 0;
  *SenseDataArray     = ScsiDiskDevice->SenseData;
  PtrSenseData        = ScsiDiskDevice->SenseData;

  for (SenseReq = TRUE; SenseReq;) {
    Status = ScsiRequestSenseCommand (
              ScsiDiskDevice->ScsiIo,
              EfiScsiStallSeconds (2),
              PtrSenseData,
              &SenseDataLength,
              &HostAdapterStatus,
              &TargetStatus
              );
     if ((Status == EFI_SUCCESS) || (Status == EFI_WARN_BUFFER_TOO_SMALL)) {
        FallStatus = EFI_SUCCESS;
  
     } else if ((Status == EFI_TIMEOUT) || (Status == EFI_NOT_READY)) {
       *NeedRetry  = TRUE;
       FallStatus  = EFI_DEVICE_ERROR;
 
     } else if ((Status == EFI_INVALID_PARAMETER) || (Status == EFI_UNSUPPORTED)) {
       *NeedRetry  = FALSE;
       FallStatus  = EFI_DEVICE_ERROR;
 
     } else if (Status == EFI_DEVICE_ERROR) {
        if (AskResetIfError) {
          ScsiDiskDevice->ScsiIo->ResetDevice (ScsiDiskDevice->ScsiIo);
        }
  
        FallStatus = EFI_DEVICE_ERROR;
    }

    if (EFI_ERROR (FallStatus)) {
      if (*NumberOfSenseKeys != 0) {
        *NeedRetry = FALSE;
        return EFI_SUCCESS;
      } else {
        return EFI_DEVICE_ERROR;
      }
    }

    (*NumberOfSenseKeys) += 1;

    //
    // no more sense key or number of sense keys exceeds predefined,
    // skip the loop.
    //
    if ((PtrSenseData->Sense_Key == EFI_SCSI_SK_NO_SENSE) || 
        (*NumberOfSenseKeys == ScsiDiskDevice->SenseDataNumber)) {
      SenseReq = FALSE;
    }
    PtrSenseData += 1;
  }
  return EFI_SUCCESS;
}

VOID
GetMediaInfo (
  SCSI_DISK_DEV                 *ScsiDiskDevice,
  EFI_SCSI_DISK_CAPACITY_DATA   *Capacity
  )
/*++

Routine Description:

  Get information from media read capacity command

Arguments:

  ScsiDiskDevice  - The pointer of SCSI_DISK_DEV
  Capacity        - The pointer of EFI_SCSI_DISK_CAPACITY_DATA

Returns:

  NONE

--*/
{
  ScsiDiskDevice->BlkIo.Media->LastBlock =  (Capacity->LastLba3 << 24) |
                                            (Capacity->LastLba2 << 16) |
                                            (Capacity->LastLba1 << 8)  |
                                             Capacity->LastLba0;

  ScsiDiskDevice->BlkIo.Media->MediaPresent = TRUE;
  ScsiDiskDevice->BlkIo.Media->BlockSize = (Capacity->BlockSize3 << 24) |
                                           (Capacity->BlockSize2 << 16) | 
                                           (Capacity->BlockSize1 << 8)  |
                                            Capacity->BlockSize0;
  if (ScsiDiskDevice->DeviceType == EFI_SCSI_TYPE_DISK) {
    ScsiDiskDevice->BlkIo.Media->BlockSize = 0x200;
  }

  if (ScsiDiskDevice->DeviceType == EFI_SCSI_TYPE_CDROM) {
    ScsiDiskDevice->BlkIo.Media->BlockSize = 0x800;
  }
}

VOID
ParseInquiryData (
  SCSI_DISK_DEV   *ScsiDiskDevice
  )
/*++

Routine Description:

  Parse Inquiry data

Arguments:

  ScsiDiskDevice  - The pointer of SCSI_DISK_DEV

Returns:

  NONE

--*/
{
  ScsiDiskDevice->FixedDevice               = (BOOLEAN) (ScsiDiskDevice->InquiryData.RMB ? 0 : 1);
  ScsiDiskDevice->BlkIoMedia.RemovableMedia = (BOOLEAN) (!ScsiDiskDevice->FixedDevice);
}

EFI_STATUS
EFIAPI
ScsiDiskReadSectors (
  SCSI_DISK_DEV     *ScsiDiskDevice,
  VOID              *Buffer,
  EFI_LBA           Lba,
  UINTN             NumberOfBlocks
  )
/*++

Routine Description:

  Read sector from SCSI Disk

Arguments:

  ScsiDiskDevice  - The poiniter of SCSI_DISK_DEV
  Buffer          - The buffer to fill in the read out data
  Lba             - Logic block address
  NumberOfBlocks  - The number of blocks to read

Returns:

  EFI_DEVICE_ERROR
  EFI_SUCCESS

--*/
{
  UINTN               BlocksRemaining;
  UINT32              Lba32;
  UINT8               *PtrBuffer;
  UINT32              BlockSize;
  UINT32              ByteCount;
  UINT32              MaxBlock;
  UINT32              SectorCount;
  UINT64              Timeout;
  EFI_STATUS          Status;
  UINT8               Index;
  UINT8               MaxRetry;
  BOOLEAN             NeedRetry;
  EFI_SCSI_SENSE_DATA *SenseData;
  UINTN               NumberOfSenseKeys;

  SenseData         = NULL;
  NumberOfSenseKeys = 0;

  Status            = EFI_SUCCESS;

  BlocksRemaining   = NumberOfBlocks;
  BlockSize         = ScsiDiskDevice->BlkIo.Media->BlockSize;
  //
  // limit the data bytes that can be transferred by one Read(10) Command
  //
  MaxBlock  = 65536;

  PtrBuffer = Buffer;
  Lba32     = (UINT32) Lba;

  while (BlocksRemaining > 0) {

    if (BlocksRemaining <= MaxBlock) {

      SectorCount = (UINT16) BlocksRemaining;
    } else {

      SectorCount = MaxBlock;
    }

    ByteCount = SectorCount * BlockSize;
    Timeout   = EfiScsiStallSeconds (2);

    MaxRetry  = 2;
    for (Index = 0; Index < MaxRetry; Index++) {

      Status = ScsiDiskRead10 (
                ScsiDiskDevice,
                &NeedRetry,
                &SenseData,
                &NumberOfSenseKeys,
                Timeout,
                PtrBuffer,
                &ByteCount,
                Lba32,
                SectorCount
                );
      if (!EFI_ERROR (Status)) {
        break;
      }

      if (!NeedRetry) {
        return EFI_DEVICE_ERROR;
      }

    }

    if ((Index == MaxRetry) && (Status != EFI_SUCCESS)) {
      return EFI_DEVICE_ERROR;
    }

    //
    // actual transferred sectors
    //
    SectorCount = ByteCount / BlockSize;

    Lba32 += SectorCount;
    PtrBuffer = PtrBuffer + SectorCount * BlockSize;
    BlocksRemaining -= SectorCount;
  }

  return EFI_SUCCESS;
}

EFI_STATUS
ScsiDiskWriteSectors (
  SCSI_DISK_DEV     *ScsiDiskDevice,
  VOID              *Buffer,
  EFI_LBA           Lba,
  UINTN             NumberOfBlocks
  )
/*++

Routine Description:

  Write SCSI Disk sectors

Arguments:

  ScsiDiskDevice  - The pointer of SCSI_DISK_DEV
  Buffer          - The data buffer to write sector
  Lba             - Logic block address
  NumberOfBlocks  - The number of blocks to write

Returns:

  EFI_DEVICE_ERROR 
  EFI_SUCCESS

--*/
{
  UINTN               BlocksRemaining;
  UINT32              Lba32;
  UINT8               *PtrBuffer;
  UINT32              BlockSize;
  UINT32              ByteCount;
  UINT32              MaxBlock;
  UINT32              SectorCount;
  UINT64              Timeout;
  EFI_STATUS          Status;
  UINT8               Index;
  UINT8               MaxRetry;
  BOOLEAN             NeedRetry;
  EFI_SCSI_SENSE_DATA *SenseData;
  UINTN               NumberOfSenseKeys;

  SenseData         = NULL;
  NumberOfSenseKeys = 0;

  Status            = EFI_SUCCESS;

  BlocksRemaining   = NumberOfBlocks;
  BlockSize         = ScsiDiskDevice->BlkIo.Media->BlockSize;
  //
  // limit the data bytes that can be transferred by one Write(10) Command
  //
  MaxBlock  = 65536;

  PtrBuffer = Buffer;
  Lba32     = (UINT32) Lba;

  while (BlocksRemaining > 0) {

    if (BlocksRemaining <= MaxBlock) {

      SectorCount = (UINT16) BlocksRemaining;
    } else {

      SectorCount = MaxBlock;
    }

    ByteCount = SectorCount * BlockSize;
    Timeout   = EfiScsiStallSeconds (2);
    MaxRetry  = 2;
    for (Index = 0; Index < MaxRetry; Index++) {
      Status = ScsiDiskWrite10 (
                ScsiDiskDevice,
                &NeedRetry,
                &SenseData,
                &NumberOfSenseKeys,
                Timeout,
                PtrBuffer,
                &ByteCount,
                Lba32,
                SectorCount
                );
      if (!EFI_ERROR (Status)) {
        break;
      }

      if (!NeedRetry) {
        return EFI_DEVICE_ERROR;
      }
    }

    if ((Index == MaxRetry) && (Status != EFI_SUCCESS)) {
      return EFI_DEVICE_ERROR;
    }
    //
    // actual transferred sectors
    //
    SectorCount = ByteCount / BlockSize;

    Lba32 += SectorCount;
    PtrBuffer = PtrBuffer + SectorCount * BlockSize;
    BlocksRemaining -= SectorCount;
  }

  return EFI_SUCCESS;
}

EFI_STATUS
ScsiDiskRead10 (
  SCSI_DISK_DEV         *ScsiDiskDevice,
  BOOLEAN               *NeedRetry,
  EFI_SCSI_SENSE_DATA   **SenseDataArray,
  UINTN                 *NumberOfSenseKeys,
  UINT64                Timeout,
  UINT8                 *DataBuffer,
  UINT32                *DataLength,
  UINT32                StartLba,
  UINT32                SectorSize
  )
/*++

Routine Description:

  Sumbmit Read command 

Arguments:

  ScsiDiskDevice    - The pointer of ScsiDiskDevice
  NeedRetry         - The pointer of flag indicates if needs retry if error happens
  SenseDataArray    - The pointer of an array of sense data
  NumberOfSenseKeys - The number of sense key
  Timeout           - The time to complete the command
  DataBuffer        - The buffer to fill with the read out data
  DataLength        - The length of buffer
  StartLba          - The start logic block address
  SectorSize        - The size of sector

Returns:

  EFI_STATUS
  
--*/
{
  UINT8       SenseDataLength;
  EFI_STATUS  Status;
  UINT8       HostAdapterStatus;
  UINT8       TargetStatus;

  *NeedRetry          = FALSE;
  *NumberOfSenseKeys  = 0;
  SenseDataLength     = 0;
  Status = ScsiRead10Command (
            ScsiDiskDevice->ScsiIo,
            Timeout,
            NULL,
            &SenseDataLength,
            &HostAdapterStatus,
            &TargetStatus,
            DataBuffer,
            DataLength,
            StartLba,
            SectorSize
            );
  return Status;
}

EFI_STATUS
ScsiDiskWrite10 (
  SCSI_DISK_DEV         *ScsiDiskDevice,
  BOOLEAN               *NeedRetry,
  EFI_SCSI_SENSE_DATA   **SenseDataArray,
  UINTN                 *NumberOfSenseKeys,
  UINT64                Timeout,
  UINT8                 *DataBuffer,
  UINT32                *DataLength,
  UINT32                StartLba,
  UINT32                SectorSize
  )
/*++

Routine Description:

  Submit Write Command

Arguments:

  ScsiDiskDevice    - The pointer of ScsiDiskDevice
  NeedRetry         - The pointer of flag indicates if needs retry if error happens
  SenseDataArray    - The pointer of an array of sense data
  NumberOfSenseKeys - The number of sense key
  Timeout           - The time to complete the command
  DataBuffer        - The buffer to fill with the read out data
  DataLength        - The length of buffer
  StartLba          - The start logic block address
  SectorSize        - The size of sector

Returns:

  EFI_STATUS

--*/
{
  EFI_STATUS  Status;
  UINT8       SenseDataLength;
  UINT8       HostAdapterStatus;
  UINT8       TargetStatus;

  *NeedRetry          = FALSE;
  *NumberOfSenseKeys  = 0;
  SenseDataLength     = 0;
  Status = ScsiWrite10Command (
            ScsiDiskDevice->ScsiIo,
            Timeout,
            NULL,
            &SenseDataLength,
            &HostAdapterStatus,
            &TargetStatus,
            DataBuffer,
            DataLength,
            StartLba,
            SectorSize
            );
  return Status;
}

BOOLEAN
ScsiDiskIsNoMedia (
  IN  EFI_SCSI_SENSE_DATA   *SenseData,
  IN  UINTN                 SenseCounts
  )
/*++

Routine Description:

  Check sense key to find if media presents

Arguments:

  SenseData   - The pointer of EFI_SCSI_SENSE_DATA
  SenseCounts - The number of sense key

Returns:

  BOOLEAN

--*/
{
  EFI_SCSI_SENSE_DATA *SensePtr;
  UINTN               Index;
  BOOLEAN             IsNoMedia;

  IsNoMedia = FALSE;
  SensePtr  = SenseData;

  for (Index = 0; Index < SenseCounts; Index++) {
    //
    // Sense Key is EFI_SCSI_SK_NOT_READY (0x2),
    // Additional Sense Code is ASC_NO_MEDIA (0x3A)
    //
    if ((SensePtr->Sense_Key == EFI_SCSI_SK_NOT_READY) &&
        (SensePtr->Addnl_Sense_Code == EFI_SCSI_ASC_NO_MEDIA)) {
      IsNoMedia = TRUE;
    }
    SensePtr++;
  }

  return IsNoMedia;
}

BOOLEAN
ScsiDiskIsMediaError (
  IN  EFI_SCSI_SENSE_DATA   *SenseData,
  IN  UINTN                 SenseCounts
  )
/*++

Routine Description:

  Parse sense key

Arguments:

  SenseData   - The pointer of EFI_SCSI_SENSE_DATA
  SenseCounts - The number of sense key

Returns:

  BOOLEAN

--*/
{
  EFI_SCSI_SENSE_DATA *SensePtr;
  UINTN               Index;
  BOOLEAN             IsError;

  IsError   = FALSE;
  SensePtr  = SenseData;

  for (Index = 0; Index < SenseCounts; Index++) {

    switch (SensePtr->Sense_Key) {

    case EFI_SCSI_SK_MEDIUM_ERROR:
      //
      // Sense Key is EFI_SCSI_SK_MEDIUM_ERROR (0x3)
      //
      switch (SensePtr->Addnl_Sense_Code) {

      //
      // fall through
      //
      case EFI_SCSI_ASC_MEDIA_ERR1:

      //
      // fall through
      //
      case EFI_SCSI_ASC_MEDIA_ERR2:

      //
      // fall through
      //
      case EFI_SCSI_ASC_MEDIA_ERR3:
      case EFI_SCSI_ASC_MEDIA_ERR4:
        IsError = TRUE;
        break;

      default:
        break;
      }

      break;

    case EFI_SCSI_SK_NOT_READY:
      //
      // Sense Key is EFI_SCSI_SK_NOT_READY (0x2)
      //
      switch (SensePtr->Addnl_Sense_Code) {
      //
      // Additional Sense Code is ASC_MEDIA_UPSIDE_DOWN (0x6)
      //
      case EFI_SCSI_ASC_MEDIA_UPSIDE_DOWN:
        IsError = TRUE;
        break;

      default:
        break;
      }
      break;

    default:
      break;
    }

    SensePtr++;
  }

  return IsError;
}

BOOLEAN
ScsiDiskIsHardwareError (
  IN  EFI_SCSI_SENSE_DATA   *SenseData,
  IN  UINTN                 SenseCounts
  )
/*++

Routine Description:

  Check sense key to find if hardware error happens

Arguments:

  SenseData   - The pointer of EFI_SCSI_SENSE_DATA
  SenseCounts - The number of sense key

Returns:

  BOOLEAN

--*/
{
  EFI_SCSI_SENSE_DATA *SensePtr;
  UINTN               Index;
  BOOLEAN             IsError;

  IsError   = FALSE;
  SensePtr  = SenseData;

  for (Index = 0; Index < SenseCounts; Index++) {
    
    //
    // Sense Key is EFI_SCSI_SK_HARDWARE_ERROR (0x4)
    //
    if (SensePtr->Sense_Key == EFI_SCSI_SK_HARDWARE_ERROR) {
      IsError = TRUE;
    }

    SensePtr++;
  }

  return IsError;
}

BOOLEAN
ScsiDiskIsMediaChange (
  IN  EFI_SCSI_SENSE_DATA   *SenseData,
  IN  UINTN                 SenseCounts
  )
/*++

Routine Description:

 Check sense key to find if media has changed

Arguments:

  SenseData   - The pointer of EFI_SCSI_SENSE_DATA
  SenseCounts - The number of sense key

Returns:

  BOOLEAN

--*/
{
  EFI_SCSI_SENSE_DATA *SensePtr;
  UINTN               Index;
  BOOLEAN             IsMediaChanged;

  IsMediaChanged  = FALSE;
  SensePtr        = SenseData;

  for (Index = 0; Index < SenseCounts; Index++) {
    //
    // Sense Key is EFI_SCSI_SK_UNIT_ATTENTION (0x6),
    // Additional sense code is EFI_SCSI_ASC_MEDIA_CHANGE (0x28)
    //
    if ((SensePtr->Sense_Key == EFI_SCSI_SK_UNIT_ATTENTION) &&
        (SensePtr->Addnl_Sense_Code == EFI_SCSI_ASC_MEDIA_CHANGE)) {
      IsMediaChanged = TRUE;
    }

    SensePtr++;
  }

  return IsMediaChanged;
}

BOOLEAN
ScsiDiskIsResetBefore (
  IN  EFI_SCSI_SENSE_DATA   *SenseData,
  IN  UINTN                 SenseCounts
  )
/*++

Routine Description:

  Check sense key to find if reset happens

Arguments:

  SenseData   - The pointer of EFI_SCSI_SENSE_DATA
  SenseCounts - The number of sense key

Returns:

  BOOLEAN

--*/
{
  EFI_SCSI_SENSE_DATA *SensePtr;
  UINTN               Index;
  BOOLEAN             IsResetBefore;

  IsResetBefore = FALSE;
  SensePtr      = SenseData;

  for (Index = 0; Index < SenseCounts; Index++) {
    
    //
    // Sense Key is EFI_SCSI_SK_UNIT_ATTENTION (0x6)
    // Additional Sense Code is EFI_SCSI_ASC_RESET (0x29)
    //
    if ((SensePtr->Sense_Key == EFI_SCSI_SK_UNIT_ATTENTION) &&
        (SensePtr->Addnl_Sense_Code == EFI_SCSI_ASC_RESET)) {
      IsResetBefore = TRUE;
    }

    SensePtr++;
  }

  return IsResetBefore;
}

BOOLEAN
ScsiDiskIsDriveReady (
  IN  EFI_SCSI_SENSE_DATA   *SenseData,
  IN  UINTN                 SenseCounts,
  OUT BOOLEAN               *RetryLater
  )
/*++

Routine Description:

  Check sense key to find if the drive is ready

Arguments:

  SenseData   - The pointer of EFI_SCSI_SENSE_DATA
  SenseCounts - The number of sense key
  RetryLater  - The flag means if need a retry 

Returns:

  BOOLEAN

--*/
{
  EFI_SCSI_SENSE_DATA *SensePtr;
  UINTN               Index;
  BOOLEAN             IsReady;

  IsReady     = TRUE;
  *RetryLater = FALSE;
  SensePtr    = SenseData;

  for (Index = 0; Index < SenseCounts; Index++) {

    switch (SensePtr->Sense_Key) {

    case EFI_SCSI_SK_NOT_READY:
      //
      // Sense Key is EFI_SCSI_SK_NOT_READY (0x2)
      //
      switch (SensePtr->Addnl_Sense_Code) {
      case EFI_SCSI_ASC_NOT_READY:
        //
        // Additional Sense Code is EFI_SCSI_ASC_NOT_READY (0x4)
        //
        switch (SensePtr->Addnl_Sense_Code_Qualifier) {
        case EFI_SCSI_ASCQ_IN_PROGRESS:
          //
          // Additional Sense Code Qualifier is
          // EFI_SCSI_ASCQ_IN_PROGRESS (0x1)
          //
          IsReady     = FALSE;
          *RetryLater = TRUE;
          break;

        default:
          IsReady     = FALSE;
          *RetryLater = FALSE;
          break;
        }
        break;

      default:
        break;
      }
      break;

    default:
      break;
    }

    SensePtr++;
  }

  return IsReady;
}

BOOLEAN
ScsiDiskHaveSenseKey (
  IN  EFI_SCSI_SENSE_DATA   *SenseData,
  IN  UINTN                 SenseCounts
  )
/*++

Routine Description:

  Check sense key to find if it has sense key

Arguments:

  SenseData   - The pointer of EFI_SCSI_SENSE_DATA
  SenseCounts - The number of sense key

Returns:

  BOOLEAN

--*/
{
  EFI_SCSI_SENSE_DATA *SensePtr;
  UINTN               Index;
  BOOLEAN             HaveSenseKey;

  if (SenseCounts == 0) {
    HaveSenseKey = FALSE;
  } else {
    HaveSenseKey = TRUE;
  }

  SensePtr = SenseData;

  for (Index = 0; Index < SenseCounts; Index++) {
    
    //
    // Sense Key is SK_NO_SENSE (0x0)
    //
    if ((SensePtr->Sense_Key == EFI_SCSI_SK_NO_SENSE) &&
        (Index == 0)) {
      HaveSenseKey = FALSE;
    }

    SensePtr++;
  }

  return HaveSenseKey;
}

VOID
ReleaseScsiDiskDeviceResources (
  IN  SCSI_DISK_DEV   *ScsiDiskDevice
  )
/*++

Routine Description:

  Release resource about disk device

Arguments:

  ScsiDiskDevice  - The pointer of SCSI_DISK_DEV

Returns:

  NONE

--*/
{
  if (ScsiDiskDevice == NULL) {
    return ;
  }

  if (ScsiDiskDevice->SenseData != NULL) {
    gBS->FreePool (ScsiDiskDevice->SenseData);
    ScsiDiskDevice->SenseData = NULL;
  }

  if (ScsiDiskDevice->ControllerNameTable != NULL) {
    FreeUnicodeStringTable (ScsiDiskDevice->ControllerNameTable);
    ScsiDiskDevice->ControllerNameTable = NULL;
  }

  gBS->FreePool (ScsiDiskDevice);

  ScsiDiskDevice = NULL;
}