path: root/IntelFrameworkModulePkg/Bus/Pci/IdeBusDxe/Ata.c

/** @file
  This file contains all helper functions on the ATA command 
  
  Copyright (c) 2006 - 2010, Intel Corporation. All rights reserved.<BR>
  This program and the accompanying materials
  are licensed and made available under the terms and conditions of the BSD License
  which accompanies this distribution.  The full text of the license may be found at
  http://opensource.org/licenses/bsd-license.php

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

  @par Revision Reference:
  2002-6: Add Atapi6 enhancement, support >120GB hard disk, including
  update - ATAIdentity() func
  update - AtaBlockIoReadBlocks() func
  update - AtaBlockIoWriteBlocks() func
  add    - AtaAtapi6Identify() func
  add    - AtaReadSectorsExt() func
  add    - AtaWriteSectorsExt() func
  add    - AtaPioDataInExt() func
  add    - AtaPioDataOutExt() func

**/

#include "IdeBus.h"
/**
  This function is called by ATAIdentify() to identity whether this disk
  supports ATA/ATAPI6 48bit addressing, ie support >120G capacity

  @param IdeDev pointer pointing to IDE_BLK_IO_DEV data structure, used to record
                all the information of the IDE device.

  @retval EFI_SUCCESS       The disk specified by IdeDev is a Atapi6 supported one and 
                            48-bit addressing must be used
  @retval EFI_UNSUPPORTED   The disk dosn't not support Atapi6 or it supports but the 
                            capacity is below 120G, 48bit addressing is not needed
  @retval  EFI_DEVICE_ERROR      The identify data in IdeDev is incorrect
  @retval  EFI_INVALID_PARAMETER The identify data in IdeDev is NULL.

  @note  This function must be called after DEVICE_IDENTITY command has been
          successfully returned

**/
EFI_STATUS
AtaAtapi6Identify (
  IN  IDE_BLK_IO_DEV  *IdeDev
  )
{
  UINT8             Index;
  EFI_LBA           TmpLba;
  EFI_LBA           Capacity;
  EFI_IDENTIFY_DATA *Atapi6IdentifyStruct;

  if (IdeDev->IdData == NULL) {
    return EFI_INVALID_PARAMETER;
  }

  Atapi6IdentifyStruct = IdeDev->IdData;

  if ((Atapi6IdentifyStruct->AtapiData.cmd_set_support_83 & (BIT15 | BIT14)) != 0x4000) {
    //
    // Per ATA-6 spec, word83: bit15 is zero and bit14 is one
    //
    return EFI_DEVICE_ERROR;
  }

  if ((Atapi6IdentifyStruct->AtapiData.cmd_set_support_83 & BIT10) == 0) {
    //
    // The device dosn't support 48 bit addressing
    //
    return EFI_UNSUPPORTED;
  }

  //
  // 48 bit address feature set is supported, get maximum capacity
  //
  Capacity = Atapi6IdentifyStruct->AtaData.maximum_lba_for_48bit_addressing[0];
  for (Index = 1; Index < 4; Index++) {
    //
    // Lower byte goes first: word[100] is the lowest word, word[103] is highest
    //
    TmpLba = Atapi6IdentifyStruct->AtaData.maximum_lba_for_48bit_addressing[Index];
    Capacity |= LShiftU64 (TmpLba, 16 * Index);
  }

  if (Capacity > MAX_28BIT_ADDRESSING_CAPACITY) {
    //
    // Capacity exceeds 120GB. 48-bit addressing is really needed
    //
    IdeDev->Type = Ide48bitAddressingHardDisk;

    //
    // Fill block media information:Media->LogicalPartition ,
    // Media->WriteCaching will be filledin the DiscoverIdeDevcie() function.
    //
    IdeDev->BlkIo.Media->IoAlign        = 4;
    IdeDev->BlkIo.Media->MediaId        = 1;
    IdeDev->BlkIo.Media->RemovableMedia = FALSE;
    IdeDev->BlkIo.Media->MediaPresent   = TRUE;
    IdeDev->BlkIo.Media->ReadOnly       = FALSE;
    IdeDev->BlkIo.Media->BlockSize      = 0x200;
    IdeDev->BlkIo.Media->LastBlock      = Capacity - 1;

    return EFI_SUCCESS;
  }

  return EFI_UNSUPPORTED;
}
/**
  Enable SMART of the disk if supported

  @param IdeDev pointer pointing to IDE_BLK_IO_DEV data structure,used to record 
                all the information of the IDE device.
**/
VOID
AtaSMARTSupport (
  IN  IDE_BLK_IO_DEV  *IdeDev
  )
{
  EFI_STATUS        Status;
  BOOLEAN           SMARTSupported;
  UINT8             Device;
  EFI_IDENTIFY_DATA *TmpAtaIdentifyPointer;
  UINT8             DeviceSelect;
  UINT8             LBAMid;
  UINT8             LBAHigh;

  //
  // Detect if the device supports S.M.A.R.T.
  //
  if ((IdeDev->IdData->AtaData.command_set_supported_83 & 0xc000) != 0x4000) {
    //
    // Data in word 82 is not valid (bit15 shall be zero and bit14 shall be to one)
    //
    return ;
  } else {
    if ((IdeDev->IdData->AtaData.command_set_supported_82 & 0x0001) != 0x0001) {
      //
      // S.M.A.R.T is not supported by the device
      //
      SMARTSupported = FALSE;
    } else {
      SMARTSupported = TRUE;
    }
  }

  if (!SMARTSupported) {
    //
    // Report nonsupport status code
    //
    REPORT_STATUS_CODE (
      EFI_ERROR_CODE | EFI_ERROR_MINOR,
      (EFI_IO_BUS_ATA_ATAPI | EFI_IOB_ATA_BUS_SMART_NOTSUPPORTED)
      );
  } else {
    //
    // Enable this feature
    //
    REPORT_STATUS_CODE (
      EFI_PROGRESS_CODE,
      (EFI_IO_BUS_ATA_ATAPI | EFI_IOB_ATA_BUS_SMART_ENABLE)
      );

    Device = (UINT8) ((IdeDev->Device << 4) | 0xe0);
    Status = AtaNonDataCommandIn (
              IdeDev,
              ATA_CMD_SMART,
              Device,
              ATA_SMART_ENABLE_OPERATION,
              0,
              0,
              ATA_CONSTANT_4F,
              ATA_CONSTANT_C2
              );
    //
    // Detect if this feature is enabled
    //
    TmpAtaIdentifyPointer = (EFI_IDENTIFY_DATA *) AllocateZeroPool (sizeof (EFI_IDENTIFY_DATA));
    if (TmpAtaIdentifyPointer == NULL) {
      return;
    }

    DeviceSelect          = (UINT8) ((IdeDev->Device) << 4);
    Status = AtaPioDataIn (
              IdeDev,
              (VOID *) TmpAtaIdentifyPointer,
              sizeof (EFI_IDENTIFY_DATA),
              ATA_CMD_IDENTIFY_DRIVE,
              DeviceSelect,
              0,
              0,
              0,
              0
              );
    if (EFI_ERROR (Status)) {
      gBS->FreePool (TmpAtaIdentifyPointer);
      return ;
    }

    //
    // Check if the feature is enabled
    //
    if ((TmpAtaIdentifyPointer->AtaData.command_set_feature_enb_85 & 0x0001) == 0x0001) {
      //
      // Read status data
      //
      AtaNonDataCommandIn (
        IdeDev,
        ATA_CMD_SMART,
        Device,
        ATA_SMART_RETURN_STATUS,
        0,
        0,
        ATA_CONSTANT_4F,
        ATA_CONSTANT_C2
        );
      LBAMid  = IDEReadPortB (IdeDev->PciIo, IdeDev->IoPort->CylinderLsb);
      LBAHigh = IDEReadPortB (IdeDev->PciIo, IdeDev->IoPort->CylinderMsb);

      if ((LBAMid == 0x4f) && (LBAHigh == 0xc2)) {
        //
        // The threshold exceeded condition is not detected by the device
        //
        REPORT_STATUS_CODE (
              EFI_PROGRESS_CODE,
              (EFI_IO_BUS_ATA_ATAPI | EFI_IOB_ATA_BUS_SMART_UNDERTHRESHOLD)
              );

      } else if ((LBAMid == 0xf4) && (LBAHigh == 0x2c)) {
        //
        // The threshold exceeded condition is  detected by the device
        //
        REPORT_STATUS_CODE (
              EFI_PROGRESS_CODE,
              (EFI_IO_BUS_ATA_ATAPI | EFI_IOB_ATA_BUS_SMART_OVERTHRESHOLD)
              );
      }

    } else {
      //
      // Report disabled status code
      //
      REPORT_STATUS_CODE (
            EFI_ERROR_CODE | EFI_ERROR_MINOR,
            (EFI_IO_BUS_ATA_ATAPI | EFI_IOB_ATA_BUS_SMART_DISABLED)
            );
    }

    gBS->FreePool (TmpAtaIdentifyPointer);
  }

  return ;
}
/**
  Sends out an ATA Identify Command to the specified device.

  This function is called by DiscoverIdeDevice() during its device
  identification. It sends out the ATA Identify Command to the
  specified device. Only ATA device responses to this command. If
  the command succeeds, it returns the Identify data structure which
  contains information about the device. This function extracts the
  information it needs to fill the IDE_BLK_IO_DEV data structure,
  including device type, media block size, media capacity, and etc.

  @param IdeDev  pointer pointing to IDE_BLK_IO_DEV data structure,used to record 
                 all the information of the IDE device.

  @retval EFI_SUCCESS      Identify ATA device successfully.
  @retval EFI_DEVICE_ERROR ATA Identify Device Command failed or device is not ATA device.
  @note  parameter IdeDev will be updated in this function.

**/
EFI_STATUS
ATAIdentify (
  IN  IDE_BLK_IO_DEV  *IdeDev
  )
{
  EFI_STATUS        Status;
  EFI_IDENTIFY_DATA *AtaIdentifyPointer;
  UINT32            Capacity;
  UINT8             DeviceSelect;
  UINTN				Retry;

  //
  //  AtaIdentifyPointer is used for accommodating returned IDENTIFY data of
  //  the ATA Identify command
  //
  AtaIdentifyPointer = (EFI_IDENTIFY_DATA *) AllocateZeroPool (sizeof (EFI_IDENTIFY_DATA));
  if (AtaIdentifyPointer == NULL) {
    return EFI_OUT_OF_RESOURCES;
  }

  //
  //  use ATA PIO Data In protocol to send ATA Identify command
  //  and receive data from device
  //
  DeviceSelect  = (UINT8) ((IdeDev->Device) << 4);

  
  Retry = 3;
  while (Retry > 0) {	
    Status = AtaPioDataIn (
              IdeDev,
              (VOID *) AtaIdentifyPointer,
              sizeof (EFI_IDENTIFY_DATA),
              ATA_CMD_IDENTIFY_DRIVE,
              DeviceSelect,
              0,
              0,
              0,
              0
              );
    //
    // If ATA Identify command succeeds, then according to the received
    // IDENTIFY data,
    // identify the device type ( ATA or not ).
    // If ATA device, fill the information in IdeDev.
    // If not ATA device, return IDE_DEVICE_ERROR
    //
    if (!EFI_ERROR (Status)) {

      IdeDev->IdData = AtaIdentifyPointer;

      //
      // Print ATA Module Name
      //
      PrintAtaModuleName (IdeDev);

      //
      // bit 15 of pAtaIdentify->config is used to identify whether device is
      // ATA device or ATAPI device.
      // if 0, means ATA device; if 1, means ATAPI device.
      //
      if ((AtaIdentifyPointer->AtaData.config & 0x8000) == 0x00) {
        //
        // Detect if support S.M.A.R.T. If yes, enable it as default
        //
        AtaSMARTSupport (IdeDev);

        //
        // Check whether this device needs 48-bit addressing (ATAPI-6 ata device)
        //
        Status = AtaAtapi6Identify (IdeDev);
        if (!EFI_ERROR (Status)) {
          //
          // It's a disk with >120GB capacity, initialized in AtaAtapi6Identify()
          //
          return EFI_SUCCESS;
        } else if (Status == EFI_DEVICE_ERROR) {
		  //
		  // Some disk with big capacity (>200GB) is slow when being identified
		  // and will return all zero for word83.
		  // We try twice at first. If it fails, we do a SoftRest and try again.
		  //
		  Retry--;
		  if (Retry == 1) {
		    //
		    // Do a SoftRest before the third attempt.
		    //
		    AtaSoftReset (IdeDev);
		  }
		  continue;
	    }
        //
        // This is a hard disk <= 120GB capacity, treat it as normal hard disk
        //
        IdeDev->Type = IdeHardDisk;

        //
        // Block Media Information:
        // Media->LogicalPartition , Media->WriteCaching will be filled
        // in the DiscoverIdeDevcie() function.
        //
        IdeDev->BlkIo.Media->IoAlign        = 4;
        IdeDev->BlkIo.Media->MediaId        = 1;
        IdeDev->BlkIo.Media->RemovableMedia = FALSE;
        IdeDev->BlkIo.Media->MediaPresent   = TRUE;
        IdeDev->BlkIo.Media->ReadOnly       = FALSE;
        IdeDev->BlkIo.Media->BlockSize      = 0x200;

        //
        // Calculate device capacity
        //
        Capacity = ((UINT32)AtaIdentifyPointer->AtaData.user_addressable_sectors_hi << 16) |
                  AtaIdentifyPointer->AtaData.user_addressable_sectors_lo ;
        IdeDev->BlkIo.Media->LastBlock = Capacity - 1;

        return EFI_SUCCESS;
      }

    }
  	break;
  }

  gBS->FreePool (AtaIdentifyPointer);
  //
  // Make sure the pIdData will not be freed again.
  //
  IdeDev->IdData = NULL;

  return EFI_DEVICE_ERROR;
}

/**
  This function is a helper function used to change the char order in a string. It
  is designed specially for the PrintAtaModuleName() function. After the IDE device 
  is detected, the IDE driver gets the device module name by sending ATA command 
  called ATA Identify Command or ATAPI Identify Command to the specified IDE device.
  The module name returned is a string of ASCII characters: the first character is bit8--bit15
  of the first word, the second character is BIT0--bit7 of the first word and so on. Thus
  the string can not be print directly before it is preprocessed by this func to change 
  the order of characters in each word in the string.

  @param Destination Indicates the destination string.
  @param Source      Indicates the source string.
  @param Size         the length of the string
**/
VOID
SwapStringChars (
  IN CHAR8  *Destination,
  IN CHAR8  *Source,
  IN UINT32 Size
  )
{
  UINT32  Index;
  CHAR8   Temp;

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

    Temp                    = Source[Index + 1];
    Destination[Index + 1]  = Source[Index];
    Destination[Index]      = Temp;
  }
}
/**
  This function is called by ATAIdentify() or ATAPIIdentify() to print device's module name.

  @param  IdeDev   pointer pointing to IDE_BLK_IO_DEV data structure, used to record
                   all the information of the IDE device.
**/
VOID
PrintAtaModuleName (
  IN  IDE_BLK_IO_DEV  *IdeDev
  )
{
  if (IdeDev->IdData == NULL) {
    return ;
  }

  SwapStringChars (IdeDev->ModelName, IdeDev->IdData->AtaData.ModelName, 40);
  IdeDev->ModelName[40] = 0x00;
}

/**
  This function is used to send out ATA commands conforms to the PIO Data In Protocol.

  @param IdeDev       pointer pointing to IDE_BLK_IO_DEV data structure, used to record 
                      all the information of the IDE device.
  @param Buffer       buffer contained data transferred from device to host.
  @param ByteCount    data size in byte unit of the buffer.
  @param AtaCommand   value of the Command Register
  @param Head         value of the Head/Device Register
  @param SectorCount  value of the Sector Count Register
  @param SectorNumber value of the Sector Number Register
  @param CylinderLsb  value of the low byte of the Cylinder Register
  @param CylinderMsb  value of the high byte of the Cylinder Register
  
  @retval EFI_SUCCESS      send out the ATA command and device send required data successfully.
  @retval EFI_DEVICE_ERROR command sent failed.

**/
EFI_STATUS
AtaPioDataIn (
  IN  IDE_BLK_IO_DEV  *IdeDev,
  IN  VOID            *Buffer,
  IN  UINT32          ByteCount,
  IN  UINT8           AtaCommand,
  IN  UINT8           Head,
  IN  UINT8           SectorCount,
  IN  UINT8           SectorNumber,
  IN  UINT8           CylinderLsb,
  IN  UINT8           CylinderMsb
  )
{
  UINTN       WordCount;
  UINTN       Increment;
  UINT16      *Buffer16;
  EFI_STATUS  Status;

  Status = WaitForBSYClear (IdeDev, ATATIMEOUT);
  if (EFI_ERROR (Status)) {
    return EFI_DEVICE_ERROR;
  }

  //
  //  e0:1110,0000-- bit7 and bit5 are reserved bits.
  //           bit6 set means LBA mode
  //
  IDEWritePortB (
    IdeDev->PciIo,
    IdeDev->IoPort->Head,
    (UINT8) ((IdeDev->Device << 4) | 0xe0 | Head)
    );

  //
  // All ATAPI device's ATA commands can be issued regardless of the
  // state of the DRDY
  //
  if (IdeDev->Type == IdeHardDisk) {

    Status = DRDYReady (IdeDev, ATATIMEOUT);
    if (EFI_ERROR (Status)) {
      return EFI_DEVICE_ERROR;
    }
  }
  //
  // set all the command parameters
  // Before write to all the following registers, BSY and DRQ must be 0.
  //
  Status = DRQClear2 (IdeDev, ATATIMEOUT);
  if (EFI_ERROR (Status)) {
    return EFI_DEVICE_ERROR;
  }

  if (AtaCommand == ATA_CMD_SET_FEATURES) {
    IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->Reg1.Feature, 0x03);
  }

  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->SectorCount, SectorCount);
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->SectorNumber, SectorNumber);
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->CylinderLsb, CylinderLsb);
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->CylinderMsb, CylinderMsb);

  //
  // send command via Command Register
  //
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->Reg.Command, AtaCommand);

  Buffer16 = (UINT16 *) Buffer;

  //
  // According to PIO data in protocol, host can perform a series of reads to
  // the data register after each time device set DRQ ready;
  // The data size of "a series of read" is command specific.
  // For most ATA command, data size received from device will not exceed
  // 1 sector, hence the data size for "a series of read" can be the whole data
  // size of one command request.
  // For ATA command such as Read Sector command, the data size of one ATA
  // command request is often larger than 1 sector, according to the
  // Read Sector command, the data size of "a series of read" is exactly 1
  // sector.
  // Here for simplification reason, we specify the data size for
  // "a series of read" to 1 sector (256 words) if data size of one ATA command
  // request is larger than 256 words.
  //
  Increment = 256;

  //
  // used to record bytes of currently transfered data
  //
  WordCount = 0;

  while (WordCount < ByteCount / 2) {
    //
    // Poll DRQ bit set, data transfer can be performed only when DRQ is ready.
    //
    Status = DRQReady2 (IdeDev, ATATIMEOUT);
    if (EFI_ERROR (Status)) {
      return EFI_DEVICE_ERROR;
    }

    Status = CheckErrorStatus (IdeDev);
    if (EFI_ERROR (Status)) {
      return EFI_DEVICE_ERROR;
    }

    //
    // Get the byte count for one series of read
    //
    if ((WordCount + Increment) > ByteCount / 2) {
      Increment = ByteCount / 2 - WordCount;
    }

    IDEReadPortWMultiple (
      IdeDev->PciIo,
      IdeDev->IoPort->Data,
      Increment,
      Buffer16
      );

    WordCount += Increment;
    Buffer16 += Increment;

  }

  DRQClear (IdeDev, ATATIMEOUT);

  return CheckErrorStatus (IdeDev);
}

/**
  This function is used to send out ATA commands conforms to the
  PIO Data Out Protocol.

  @param IdeDev       pointer pointing to IDE_BLK_IO_DEV data structure, used
                      to record all the information of the IDE device.
  @param *Buffer      buffer contained data transferred from host to device.
  @param ByteCount    data size in byte unit of the buffer.
  @param AtaCommand   value of the Command Register
  @param Head         value of the Head/Device Register
  @param SectorCount  value of the Sector Count Register
  @param SectorNumber value of the Sector Number Register
  @param CylinderLsb  value of the low byte of the Cylinder Register
  @param CylinderMsb  value of the high byte of the Cylinder Register

  @retval EFI_SUCCESS      send out the ATA command and device received required
                           data successfully.
  @retval EFI_DEVICE_ERROR command sent failed.

**/
EFI_STATUS
AtaPioDataOut (
  IN  IDE_BLK_IO_DEV  *IdeDev,
  IN  VOID            *Buffer,
  IN  UINT32          ByteCount,
  IN  UINT8           AtaCommand,
  IN  UINT8           Head,
  IN  UINT8           SectorCount,
  IN  UINT8           SectorNumber,
  IN  UINT8           CylinderLsb,
  IN  UINT8           CylinderMsb
  )
{
  UINTN       WordCount;
  UINTN       Increment;
  UINT16      *Buffer16;
  EFI_STATUS  Status;

  Status = WaitForBSYClear (IdeDev, ATATIMEOUT);
  if (EFI_ERROR (Status)) {
    return EFI_DEVICE_ERROR;
  }

  //
  // select device via Head/Device register.
  // Before write Head/Device register, BSY and DRQ must be 0.
  //
  Status = DRQClear2 (IdeDev, ATATIMEOUT);
  if (EFI_ERROR (Status)) {
    return EFI_DEVICE_ERROR;
  }

  //
  // e0:1110,0000-- bit7 and bit5 are reserved bits.
  //          bit6 set means LBA mode
  //
  IDEWritePortB (
    IdeDev->PciIo,
    IdeDev->IoPort->Head,
    (UINT8) ((IdeDev->Device << 4) | 0xe0 | Head)
    );

  Status = DRDYReady (IdeDev, ATATIMEOUT);
  if (EFI_ERROR (Status)) {
    return EFI_DEVICE_ERROR;
  }

  //
  // set all the command parameters
  // Before write to all the following registers, BSY and DRQ must be 0.
  //
  Status = DRQClear2 (IdeDev, ATATIMEOUT);
  if (EFI_ERROR (Status)) {
    return EFI_DEVICE_ERROR;
  }

  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->SectorCount, SectorCount);
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->SectorNumber, SectorNumber);
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->CylinderLsb, CylinderLsb);
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->CylinderMsb, CylinderMsb);

  //
  // send command via Command Register
  //
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->Reg.Command, AtaCommand);

  Buffer16 = (UINT16 *) Buffer;

  //
  // According to PIO data out protocol, host can perform a series of
  // writes to the data register after each time device set DRQ ready;
  // The data size of "a series of read" is command specific.
  // For most ATA command, data size written to device will not exceed 1 sector,
  // hence the data size for "a series of write" can be the data size of one
  // command request.
  // For ATA command such as Write Sector command, the data size of one
  // ATA command request is often larger than 1 sector, according to the
  // Write Sector command, the data size of "a series of read" is exactly
  // 1 sector.
  // Here for simplification reason, we specify the data size for
  // "a series of write" to 1 sector (256 words) if data size of one ATA command
  // request is larger than 256 words.
  //
  Increment = 256;
  WordCount = 0;

  while (WordCount < ByteCount / 2) {

    //
    // DRQReady2-- read Alternate Status Register to determine the DRQ bit
    // data transfer can be performed only when DRQ is ready.
    //
    Status = DRQReady2 (IdeDev, ATATIMEOUT);
    if (EFI_ERROR (Status)) {
      return EFI_DEVICE_ERROR;
    }

    Status = CheckErrorStatus (IdeDev);
    if (EFI_ERROR (Status)) {
      return EFI_DEVICE_ERROR;
    }

   //
   // Check the remaining byte count is less than 512 bytes
   //
   if ((WordCount + Increment) > ByteCount / 2) {
      Increment = ByteCount / 2 - WordCount;
    }
    //
    // perform a series of write without check DRQ ready
    //

    IDEWritePortWMultiple (
      IdeDev->PciIo,
      IdeDev->IoPort->Data,
      Increment,
      Buffer16
      );
    WordCount += Increment;
    Buffer16 += Increment;

  }

  DRQClear (IdeDev, ATATIMEOUT);

  return CheckErrorStatus (IdeDev);
}

/**
  This function is used to analyze the Status Register and print out
  some debug information and if there is ERR bit set in the Status
  Register, the Error Register's value is also be parsed and print out.

  @param IdeDev  pointer pointing to IDE_BLK_IO_DEV data structure, used to 
                 record all the information of the IDE device.

  @retval EFI_SUCCESS       No err information in the Status Register.
  @retval EFI_DEVICE_ERROR  Any err information in the Status Register.

**/
EFI_STATUS
CheckErrorStatus (
  IN  IDE_BLK_IO_DEV  *IdeDev
  )
{
  UINT8 StatusRegister;
  UINT8 ErrorRegister;

  StatusRegister = IDEReadPortB (IdeDev->PciIo, IdeDev->IoPort->Reg.Status);

  DEBUG_CODE_BEGIN ();

  if ((StatusRegister & ATA_STSREG_DWF) != 0) {
    DEBUG (
      (EFI_D_BLKIO,
      "CheckErrorStatus()-- %02x : Error : Write Fault\n",
      StatusRegister)
      );
  }

  if ((StatusRegister & ATA_STSREG_CORR) != 0) {
    DEBUG (
      (EFI_D_BLKIO,
      "CheckErrorStatus()-- %02x : Error : Corrected Data\n",
      StatusRegister)
      );
   }

  if ((StatusRegister & ATA_STSREG_ERR) != 0) {
    ErrorRegister = IDEReadPortB (IdeDev->PciIo, IdeDev->IoPort->Reg1.Error);

    if ((ErrorRegister & ATA_ERRREG_BBK) != 0) {
      DEBUG (
        (EFI_D_BLKIO,
        "CheckErrorStatus()-- %02x : Error : Bad Block Detected\n",
        ErrorRegister)
        );
      }

      if ((ErrorRegister & ATA_ERRREG_UNC) != 0) {
        DEBUG (
          (EFI_D_BLKIO,
          "CheckErrorStatus()-- %02x : Error : Uncorrectable Data\n",
          ErrorRegister)
          );
      }

      if ((ErrorRegister & ATA_ERRREG_MC) != 0) {
        DEBUG (
          (EFI_D_BLKIO,
          "CheckErrorStatus()-- %02x : Error : Media Change\n",
          ErrorRegister)
          );
      }

      if ((ErrorRegister & ATA_ERRREG_ABRT) != 0) {
        DEBUG (
          (EFI_D_BLKIO,
          "CheckErrorStatus()-- %02x : Error : Abort\n",
          ErrorRegister)
          );
      }

      if ((ErrorRegister & ATA_ERRREG_TK0NF) != 0) {
        DEBUG (
          (EFI_D_BLKIO,
          "CheckErrorStatus()-- %02x : Error : Track 0 Not Found\n",
          ErrorRegister)
          );
      }

      if ((ErrorRegister & ATA_ERRREG_AMNF) != 0) {
        DEBUG (
          (EFI_D_BLKIO,
          "CheckErrorStatus()-- %02x : Error : Address Mark Not Found\n",
          ErrorRegister)
          );
      }
    }

  DEBUG_CODE_END ();

  if ((StatusRegister & (ATA_STSREG_ERR | ATA_STSREG_DWF | ATA_STSREG_CORR)) == 0) {
    return EFI_SUCCESS;
  }

  return EFI_DEVICE_ERROR;

}

/**
  This function is called by the AtaBlkIoReadBlocks() to perform reading from 
  media in block unit.

  @param IdeDev         pointer pointing to IDE_BLK_IO_DEV data structure, used to record 
                        all the information of the IDE device.
  @param DataBuffer     A pointer to the destination buffer for the data.
  @param Lba            The starting logical block address to read from on the device media.
  @param NumberOfBlocks The number of transfer data blocks.
  
  @return status is fully dependent on the return status of AtaPioDataIn() function.

**/
EFI_STATUS
AtaReadSectors (
  IN  IDE_BLK_IO_DEV  *IdeDev,
  IN  VOID            *DataBuffer,
  IN  EFI_LBA         Lba,
  IN  UINTN           NumberOfBlocks
  )
{
  EFI_STATUS  Status;
  UINTN       BlocksRemaining;
  UINT32      Lba32;
  UINT8       Lba0;
  UINT8       Lba1;
  UINT8       Lba2;
  UINT8       Lba3;
  UINT8       AtaCommand;
  UINT8       SectorCount8;
  UINT16      SectorCount;
  UINTN       ByteCount;
  VOID        *Buffer;

  Buffer = DataBuffer;

  //
  // Using ATA Read Sector(s) command (opcode=0x20) with PIO DATA IN protocol
  //
  AtaCommand      = ATA_CMD_READ_SECTORS;


  BlocksRemaining = NumberOfBlocks;

  Lba32           = (UINT32) Lba;

  Status          = EFI_SUCCESS;

  while (BlocksRemaining > 0) {

    //
    // in ATA-3 spec, LBA is in 28 bit width
    //
    Lba0  = (UINT8) Lba32;
    Lba1  = (UINT8) (Lba32 >> 8);
    Lba2  = (UINT8) (Lba32 >> 16);
    //
    // low 4 bit of Lba3 stands for LBA bit24~bit27.
    //
    Lba3 = (UINT8) ((Lba32 >> 24) & 0x0f);

    if (BlocksRemaining >= 0x100) {

      //
      //  SectorCount8 is sent to Sector Count register, 0x00 means 256
      //  sectors to be read
      //
      SectorCount8 = 0x00;
      //
      //  SectorCount is used to record the number of sectors to be read
      //
      SectorCount = 256;
    } else {

      SectorCount8  = (UINT8) BlocksRemaining;
      SectorCount   = (UINT16) BlocksRemaining;
    }

    //
    // ByteCount is the number of bytes that will be read
    //
    ByteCount = SectorCount * (IdeDev->BlkIo.Media->BlockSize);

    //
    // call AtaPioDataIn() to send Read Sector Command and receive data read
    //
    Status = AtaPioDataIn (
              IdeDev,
              Buffer,
              (UINT32) ByteCount,
              AtaCommand,
              Lba3,
              SectorCount8,
              Lba0,
              Lba1,
              Lba2
              );
    if (EFI_ERROR (Status)) {
      return Status;
    }

    Lba32 += SectorCount;
    Buffer = ((UINT8 *) Buffer + ByteCount);
    BlocksRemaining -= SectorCount;
  }

  return Status;
}

/**
  This function is called by the AtaBlkIoWriteBlocks() to perform writing onto 
  media in block unit.

  @param IdeDev         pointer pointing to IDE_BLK_IO_DEV data structure,used to record
                        all the information of the IDE device.
  @param BufferData     A pointer to the source buffer for the data.
  @param Lba            The starting logical block address to write onto the device media.
  @param NumberOfBlocks The number of transfer data blocks.
  
  @return status is fully dependent on the return status of AtaPioDataIn() function.

**/
EFI_STATUS
AtaWriteSectors (
  IN  IDE_BLK_IO_DEV  *IdeDev,
  IN  VOID            *BufferData,
  IN  EFI_LBA         Lba,
  IN  UINTN           NumberOfBlocks
  )
{
  EFI_STATUS  Status;
  UINTN       BlocksRemaining;
  UINT32      Lba32;
  UINT8       Lba0;
  UINT8       Lba1;
  UINT8       Lba2;
  UINT8       Lba3;
  UINT8       AtaCommand;
  UINT8       SectorCount8;
  UINT16      SectorCount;
  UINTN       ByteCount;
  VOID        *Buffer;

  Buffer = BufferData;

  //
  // Using Write Sector(s) command (opcode=0x30) with PIO DATA OUT protocol
  //
  AtaCommand      = ATA_CMD_WRITE_SECTORS;

  BlocksRemaining = NumberOfBlocks;

  Lba32           = (UINT32) Lba;

  Status          = EFI_SUCCESS;

  while (BlocksRemaining > 0) {

    Lba0  = (UINT8) Lba32;
    Lba1  = (UINT8) (Lba32 >> 8);
    Lba2  = (UINT8) (Lba32 >> 16);
    Lba3  = (UINT8) ((Lba32 >> 24) & 0x0f);

    if (BlocksRemaining >= 0x100) {

      //
      //  SectorCount8 is sent to Sector Count register, 0x00 means 256 sectors
      //  to be written
      //
      SectorCount8 = 0x00;
      //
      //  SectorCount is used to record the number of sectors to be written
      //
      SectorCount = 256;
    } else {

      SectorCount8  = (UINT8) BlocksRemaining;
      SectorCount   = (UINT16) BlocksRemaining;
    }

    ByteCount = SectorCount * (IdeDev->BlkIo.Media->BlockSize);

    Status = AtaPioDataOut (
              IdeDev,
              Buffer,
              (UINT32) ByteCount,
              AtaCommand,
              Lba3,
              SectorCount8,
              Lba0,
              Lba1,
              Lba2
              );
    if (EFI_ERROR (Status)) {
      return Status;
    }

    Lba32 += SectorCount;
    Buffer = ((UINT8 *) Buffer + ByteCount);
    BlocksRemaining -= SectorCount;
  }

  return Status;
}
/**
  This function is used to implement the Soft Reset on the specified device. But,
  the ATA Soft Reset mechanism is so strong a reset method that it will force 
  resetting on both devices connected to the same cable.

  It is called by IdeBlkIoReset(), a interface function of Block
  I/O protocol.

  This function can also be used by the ATAPI device to perform reset when
  ATAPI Reset command is failed.

  @param IdeDev  pointer pointing to IDE_BLK_IO_DEV data structure, used to record
                 all the information of the IDE device.
  @retval EFI_SUCCESS       Soft reset completes successfully.
  @retval EFI_DEVICE_ERROR  Any step during the reset process is failed.

  @note  The registers initial values after ATA soft reset are different
         to the ATA device and ATAPI device.
**/
EFI_STATUS
AtaSoftReset (
  IN  IDE_BLK_IO_DEV  *IdeDev
  )
{

  UINT8 DeviceControl;

  DeviceControl = 0;
  //
  // set SRST bit to initiate soft reset
  //
  DeviceControl |= ATA_CTLREG_SRST;

  //
  // disable Interrupt
  //
  DeviceControl |= BIT1;

  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->Alt.DeviceControl, DeviceControl);

  //
  // SRST should assert for at least 5 us, we use 10 us for
  // better compatibility
  //
  gBS->Stall (10);

  //
  // Enable interrupt to support UDMA, and clear SRST bit
  //
  DeviceControl = 0;
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->Alt.DeviceControl, DeviceControl);

  //
  // Wait for at least 2 ms to check BSY status, we use 10 ms
  // for better compatibility
  //
  gBS->Stall(10000);
  //
  // slave device needs at most 31s to clear BSY
  //
  if (WaitForBSYClear (IdeDev, 31000) == EFI_TIMEOUT) {
    return EFI_DEVICE_ERROR;
  }

  return EFI_SUCCESS;
}
/**
  This function is used to send out ATA commands conforms to the PIO Data In 
  Protocol, supporting ATA/ATAPI-6 standard

  Comparing with ATA-3 data in protocol, we have two differents here:
  1. Do NOT wait for DRQ clear before sending command into IDE device.(the
  wait will frequently fail... cause writing function return error)

  2. Do NOT wait for DRQ clear after all data readed.(the wait greatly
  slow down writing performance by 100 times!)

  @param IdeDev       pointer pointing to IDE_BLK_IO_DEV data structure, used
                      to record all the information of the IDE device.
  @param Buffer       buffer contained data transferred from device to host.
  @param ByteCount    data size in byte unit of the buffer.
  @param AtaCommand   value of the Command Register
  @param StartLba     the start LBA of this transaction
  @param SectorCount  the count of sectors to be transfered

  @retval EFI_SUCCESS      send out the ATA command and device send required data successfully.
  @retval EFI_DEVICE_ERROR command sent failed.

**/
EFI_STATUS
AtaPioDataInExt (
  IN  IDE_BLK_IO_DEV  *IdeDev,
  IN  OUT VOID        *Buffer,
  IN  UINT32          ByteCount,
  IN  UINT8           AtaCommand,
  IN  EFI_LBA         StartLba,
  IN  UINT16          SectorCount
  )
{
  UINT8       DevSel;
  UINT8       SectorCount8;
  UINT8       LbaLow;
  UINT8       LbaMid;
  UINT8       LbaHigh;
  UINTN       WordCount;
  UINTN       Increment;
  UINT16      *Buffer16;
  EFI_STATUS  Status;

  Status = WaitForBSYClear (IdeDev, ATATIMEOUT);
  if (EFI_ERROR (Status)) {
    return EFI_DEVICE_ERROR;
  }

  //
  // Select device, set bit6 as 1 to indicate LBA mode is used
  //
  DevSel = (UINT8) (IdeDev->Device << 4);
  DevSel |= 0x40;
  IDEWritePortB (
    IdeDev->PciIo,
    IdeDev->IoPort->Head,
    DevSel
    );

  //
  // Wait for DRDY singnal asserting. ATAPI device needn't wait
  //
  if ( (IdeDev->Type == IdeHardDisk)  ||
        (IdeDev->Type == Ide48bitAddressingHardDisk)) {

    Status = DRDYReady (IdeDev, ATATIMEOUT);
    if (EFI_ERROR (Status)) {
      return EFI_DEVICE_ERROR;
    }
  }

  //
  // Fill feature register if needed
  //
  if (AtaCommand == ATA_CMD_SET_FEATURES) {
    IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->Reg1.Feature, 0x03);
  }

  //
  // Fill the sector count register, which is a two-byte FIFO. Need write twice.
  //
  SectorCount8 = (UINT8) (SectorCount >> 8);
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->SectorCount, SectorCount8);

  SectorCount8 = (UINT8) SectorCount;
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->SectorCount, SectorCount8);

  //
  // Fill the start LBA registers, which are also two-byte FIFO
  //
  LbaLow  = (UINT8) RShiftU64 (StartLba, 24);
  LbaMid  = (UINT8) RShiftU64 (StartLba, 32);
  LbaHigh = (UINT8) RShiftU64 (StartLba, 40);
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->SectorNumber, LbaLow);
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->CylinderLsb, LbaMid);
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->CylinderMsb, LbaHigh);

  LbaLow  = (UINT8) StartLba;
  LbaMid  = (UINT8) RShiftU64 (StartLba, 8);
  LbaHigh = (UINT8) RShiftU64 (StartLba, 16);
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->SectorNumber, LbaLow);
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->CylinderLsb, LbaMid);
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->CylinderMsb, LbaHigh);

  //
  // Send command via Command Register, invoking the processing of this command
  //
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->Reg.Command, AtaCommand);

  Buffer16 = (UINT16 *) Buffer;

  //
  // According to PIO data in protocol, host can perform a series of reads to
  // the data register after each time device set DRQ ready;
  //

  //
  // 256 words
  //
  Increment = 256;

  //
  // used to record bytes of currently transfered data
  //
  WordCount = 0;

  while (WordCount < ByteCount / 2) {
    //
    // Poll DRQ bit set, data transfer can be performed only when DRQ is ready.
    //
    Status = DRQReady2 (IdeDev, ATATIMEOUT);
    if (EFI_ERROR (Status)) {
      return EFI_DEVICE_ERROR;
    }

    Status = CheckErrorStatus (IdeDev);
    if (EFI_ERROR (Status)) {
      return EFI_DEVICE_ERROR;
    }

    //
    // Get the byte count for one series of read
    //
    if ((WordCount + Increment) > ByteCount / 2) {
      Increment = ByteCount / 2 - WordCount;
    }

    IDEReadPortWMultiple (
      IdeDev->PciIo,
      IdeDev->IoPort->Data,
      Increment,
      Buffer16
      );

    WordCount += Increment;
    Buffer16 += Increment;

  }

  return CheckErrorStatus (IdeDev);
}
/**
  Send ATA Ext command into device with NON_DATA protocol.

  @param  IdeDev Standard IDE device private data structure
  @param  AtaCommand The ATA command to be sent
  @param  Device The value in Device register
  @param  Feature The value in Feature register
  @param  SectorCount The value in SectorCount register
  @param  LbaAddress The LBA address in 48-bit mode

  @retval  EFI_SUCCESS Reading succeed
  @retval  EFI_DEVICE_ERROR Error executing commands on this device.

**/
EFI_STATUS
AtaCommandIssueExt (
  IN  IDE_BLK_IO_DEV  *IdeDev,
  IN  UINT8           AtaCommand,
  IN  UINT8           Device,
  IN  UINT16          Feature,
  IN  UINT16          SectorCount,
  IN  EFI_LBA         LbaAddress
  )
{
  EFI_STATUS  Status;
  UINT8       SectorCount8;
  UINT8       Feature8;
  UINT8       LbaLow;
  UINT8       LbaMid;
  UINT8       LbaHigh;

  Status = WaitForBSYClear (IdeDev, ATATIMEOUT);
  if (EFI_ERROR (Status)) {
    return EFI_DEVICE_ERROR;
  }

  //
  // Select device (bit4), set LBA mode(bit6) (use 0xe0 for compatibility)
  //
  IDEWritePortB (
    IdeDev->PciIo,
    IdeDev->IoPort->Head,
    (UINT8) ((IdeDev->Device << 4) | 0xe0)
    );

  //
  // ATA commands for ATA device must be issued when DRDY is set
  //
  Status = DRDYReady (IdeDev, ATATIMEOUT);
  if (EFI_ERROR (Status)) {
    return EFI_DEVICE_ERROR;
  }

  //
  // Pass parameter into device register block
  //
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->Head, Device);

  //
  // Fill the feature register, which is a two-byte FIFO. Need write twice.
  //
  Feature8 = (UINT8) (Feature >> 8);
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->Reg1.Feature, Feature8);

  Feature8 = (UINT8) Feature;
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->Reg1.Feature, Feature8);

  //
  // Fill the sector count register, which is a two-byte FIFO. Need write twice.
  //
  SectorCount8 = (UINT8) (SectorCount >> 8);
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->SectorCount, SectorCount8);

  SectorCount8 = (UINT8) SectorCount;
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->SectorCount, SectorCount8);

  //
  // Fill the start LBA registers, which are also two-byte FIFO
  //
  LbaLow = (UINT8) RShiftU64 (LbaAddress, 24);
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->SectorNumber, LbaLow);
  LbaLow = (UINT8) LbaAddress;
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->SectorNumber, LbaLow);

  LbaMid = (UINT8) RShiftU64 (LbaAddress, 32);
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->CylinderLsb, LbaMid);
  LbaMid = (UINT8) RShiftU64 (LbaAddress, 8);
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->CylinderLsb, LbaMid);

  LbaHigh = (UINT8) RShiftU64 (LbaAddress, 40);
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->CylinderMsb, LbaHigh);
  LbaHigh = (UINT8) RShiftU64 (LbaAddress, 16);
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->CylinderMsb, LbaHigh);

  //
  // Work around for Segate 160G disk writing
  //
  gBS->Stall (1800);

  //
  // Send command via Command Register
  //
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->Reg.Command, AtaCommand);

  //
  // Stall at least 400ns
  //
  gBS->Stall (100);

  return EFI_SUCCESS;
}
/**
  Send ATA Ext command into device with NON_DATA protocol

  @param  IdeDev Standard IDE device private data structure
  @param  AtaCommand The ATA command to be sent
  @param  Device The value in Device register
  @param  Feature The value in Feature register
  @param  SectorCount The value in SectorCount register
  @param  LbaAddress The LBA address in 48-bit mode

  @retval  EFI_SUCCESS Reading succeed
  @retval  EFI_DEVICE_ERROR Error executing commands on this device.

**/
EFI_STATUS
AtaCommandIssue (
  IN  IDE_BLK_IO_DEV  *IdeDev,
  IN  UINT8           AtaCommand,
  IN  UINT8           Device,
  IN  UINT16          Feature,
  IN  UINT16          SectorCount,
  IN  EFI_LBA         LbaAddress
  )
{
  EFI_STATUS  Status;
  UINT8       SectorCount8;
  UINT8       Feature8;
  UINT8       Lba0;
  UINT8       Lba1;
  UINT8       Lba2;
  UINT8       Lba3;

  Status = WaitForBSYClear (IdeDev, ATATIMEOUT);
  if (EFI_ERROR (Status)) {
    return EFI_DEVICE_ERROR;
  }

  //
  // Select device (bit4), set LBA mode(bit6) (use 0xe0 for compatibility)
  //
  IDEWritePortB (
    IdeDev->PciIo,
    IdeDev->IoPort->Head,
    (UINT8) ((IdeDev->Device << 4) | 0xe0)
    );

  //
  // ATA commands for ATA device must be issued when DRDY is set
  //
  Status = DRDYReady (IdeDev, ATATIMEOUT);
  if (EFI_ERROR (Status)) {
    return EFI_DEVICE_ERROR;
  }

  Lba0  = (UINT8) LbaAddress;
  Lba1  = (UINT8) RShiftU64 (LbaAddress, 8);
  Lba2  = (UINT8) RShiftU64 (LbaAddress, 16);
  Lba3  = (UINT8) RShiftU64 (LbaAddress, 24);
  Device = (UINT8) (Device | Lba3);

  //
  // Pass parameter into device register block
  //
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->Head, Device);

  //
  // Fill the feature register, which is a two-byte FIFO. Need write twice.
  //
  Feature8 = (UINT8) Feature;
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->Reg1.Feature, Feature8);

  //
  // Fill the sector count register, which is a two-byte FIFO. Need write twice.
  //
  SectorCount8 = (UINT8) SectorCount;
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->SectorCount, SectorCount8);

  //
  // Fill the start LBA registers, which are also two-byte FIFO
  //

  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->SectorNumber, Lba0);
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->CylinderLsb, Lba1);
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->CylinderMsb, Lba2);

  //
  // Send command via Command Register
  //
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->Reg.Command, AtaCommand);

  //
  // Stall at least 400ns
  //
  gBS->Stall (100);

  return EFI_SUCCESS;
}
/**
  Perform an ATA Udma operation (Read, ReadExt, Write, WriteExt).

  @param IdeDev         pointer pointing to IDE_BLK_IO_DEV data structure, used
                        to record all the information of the IDE device.
  @param DataBuffer     A pointer to the source buffer for the data.
  @param StartLba       The starting logical block address to write to
                        on the device media.
  @param NumberOfBlocks The number of transfer data blocks.
  @param UdmaOp         The perform operations could be AtaUdmaReadOp, AtaUdmaReadExOp,
                        AtaUdmaWriteOp, AtaUdmaWriteExOp

  @retval EFI_SUCCESS          the operation is successful.
  @retval EFI_OUT_OF_RESOURCES Build PRD table failed
  @retval EFI_UNSUPPORTED      Unknown channel or operations command
  @retval EFI_DEVICE_ERROR     Ata command execute failed

**/
EFI_STATUS
DoAtaUdma (
  IN  IDE_BLK_IO_DEV      *IdeDev,
  IN  VOID                *DataBuffer,
  IN  EFI_LBA             StartLba,
  IN  UINTN               NumberOfBlocks,
  IN  ATA_UDMA_OPERATION  UdmaOp
  )
{
  IDE_DMA_PRD                   *PrdAddr;
  IDE_DMA_PRD                   *UsedPrdAddr;
  IDE_DMA_PRD                   *TempPrdAddr;
  UINT8                         RegisterValue;
  UINT8                         Device;
  UINT64                        IoPortForBmic;
  UINT64                        IoPortForBmis;
  UINT64                        IoPortForBmid;
  EFI_STATUS                    Status;
  UINTN                         PrdTableNum;
  UINTN                         ByteCount;
  UINTN                         ByteAvailable;
  UINT8                         *PrdBuffer;
  UINTN                         RemainBlockNum;
  UINT8                         DeviceControl;
  UINT32                        Count;
  UINTN                         PageCount;
  VOID                          *Map;
  VOID                          *MemPage;
  EFI_PHYSICAL_ADDRESS          DeviceAddress;
  UINTN                         MaxDmaCommandSectors;
  EFI_PCI_IO_PROTOCOL_OPERATION PciIoProtocolOp;
  UINT8                         AtaCommand;

  switch (UdmaOp) {
  case AtaUdmaReadOp:
    MaxDmaCommandSectors = ATAPI_MAX_DMA_CMD_SECTORS;
    PciIoProtocolOp      = EfiPciIoOperationBusMasterWrite;
    AtaCommand           = ATA_CMD_READ_DMA;
    break;
  case AtaUdmaReadExtOp:
    MaxDmaCommandSectors = ATAPI_MAX_DMA_EXT_CMD_SECTORS;
    PciIoProtocolOp      = EfiPciIoOperationBusMasterWrite;
    AtaCommand           = ATA_CMD_READ_DMA_EXT;
    break;
  case AtaUdmaWriteOp:
    MaxDmaCommandSectors = ATAPI_MAX_DMA_CMD_SECTORS;
    PciIoProtocolOp      = EfiPciIoOperationBusMasterRead;
    AtaCommand           = ATA_CMD_WRITE_DMA;
    break;
  case AtaUdmaWriteExtOp:
    MaxDmaCommandSectors = ATAPI_MAX_DMA_EXT_CMD_SECTORS;
    PciIoProtocolOp      = EfiPciIoOperationBusMasterRead;
    AtaCommand           = ATA_CMD_WRITE_DMA_EXT;
    break;
  default:
    return EFI_UNSUPPORTED;
    break;
  }

  //
  // Select device
  //
  Device = (UINT8) ((IdeDev->Device << 4) | 0xe0);
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->Head, Device);

  //
  // Enable interrupt to support UDMA
  //
  DeviceControl = 0;
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->Alt.DeviceControl, DeviceControl);

  if (IdePrimary == IdeDev->Channel) {
    IoPortForBmic = IdeDev->IoPort->BusMasterBaseAddr + BMICP_OFFSET;
    IoPortForBmis = IdeDev->IoPort->BusMasterBaseAddr + BMISP_OFFSET;
    IoPortForBmid = IdeDev->IoPort->BusMasterBaseAddr + BMIDP_OFFSET;
  } else {
    if (IdeSecondary == IdeDev->Channel) {
      IoPortForBmic = IdeDev->IoPort->BusMasterBaseAddr + BMICS_OFFSET;
      IoPortForBmis = IdeDev->IoPort->BusMasterBaseAddr + BMISS_OFFSET;
      IoPortForBmid = IdeDev->IoPort->BusMasterBaseAddr + BMIDS_OFFSET;
    } else {
      return EFI_UNSUPPORTED;
    }
  }

  //
  // Read BMIS register and clear ERROR and INTR bit
  //
  IdeDev->PciIo->Io.Read (
					  IdeDev->PciIo,
					  EfiPciIoWidthUint8,
					  EFI_PCI_IO_PASS_THROUGH_BAR,
					  IoPortForBmis,
					  1,
					  &RegisterValue
					  );
  
  RegisterValue |= (BMIS_INTERRUPT | BMIS_ERROR);
  
  IdeDev->PciIo->Io.Write (
					  IdeDev->PciIo,
					  EfiPciIoWidthUint8,
					  EFI_PCI_IO_PASS_THROUGH_BAR,
					  IoPortForBmis,
					  1,
					  &RegisterValue
					  );

  Status = EFI_SUCCESS;
  
  RemainBlockNum = NumberOfBlocks;
  while (RemainBlockNum > 0) {

    if (RemainBlockNum >= MaxDmaCommandSectors) {
      //
      //  SectorCount is used to record the number of sectors to be read
      //  Max 65536 sectors can be transfered at a time.
      //
      NumberOfBlocks = MaxDmaCommandSectors;
      RemainBlockNum -= MaxDmaCommandSectors;
    } else {
      NumberOfBlocks  = (UINT16) RemainBlockNum;
      RemainBlockNum  = 0;
    }

    //
    // Calculate the number of PRD table to make sure the memory region
    // not cross 64K boundary
    //
    ByteCount   = NumberOfBlocks * IdeDev->BlkIo.Media->BlockSize;
    PrdTableNum = ((ByteCount >> 16) + 1) + 1;

    //
    // Build PRD table
    //
    PageCount = EFI_SIZE_TO_PAGES (2 * PrdTableNum * sizeof (IDE_DMA_PRD));
    Status = IdeDev->PciIo->AllocateBuffer (
                    IdeDev->PciIo,
                    AllocateAnyPages,
                    EfiBootServicesData,
                    PageCount,
                    &MemPage,
                    0
                    );
    if (EFI_ERROR (Status)) {
      return EFI_OUT_OF_RESOURCES;
    }
    ZeroMem ((VOID *) ((UINTN) MemPage), EFI_PAGES_TO_SIZE (PageCount));

    PrdAddr = (IDE_DMA_PRD *) ((UINTN) MemPage);
    //
    // To make sure PRD is allocated in one 64K page
    //
    if (((UINTN) PrdAddr & 0x0FFFF) > (((UINTN) PrdAddr + PrdTableNum * sizeof (IDE_DMA_PRD) - 1) & 0x0FFFF)) {
      UsedPrdAddr = (IDE_DMA_PRD *) ((UINTN) ((UINT8 *) PrdAddr + 0x10000) & 0xFFFF0000);
    } else {
      if ((UINTN) PrdAddr & 0x03) {
        UsedPrdAddr = (IDE_DMA_PRD *) ((UINTN) ((UINT8 *) PrdAddr + 0x04) & 0xFFFFFFFC);
      } else {
        UsedPrdAddr = PrdAddr;
      }
    }

    //
    // Build the PRD table
    //
    Status = IdeDev->PciIo->Map (
                       IdeDev->PciIo,
                       PciIoProtocolOp,
                       DataBuffer,
                       &ByteCount,
                       &DeviceAddress,
                       &Map
                       );
    if (EFI_ERROR (Status)) {
      IdeDev->PciIo->FreeBuffer (IdeDev->PciIo, PageCount, MemPage);
      return EFI_OUT_OF_RESOURCES;
    }
    PrdBuffer   = (VOID *) ((UINTN) DeviceAddress);
    TempPrdAddr = UsedPrdAddr;
    while (TRUE) {

      ByteAvailable = 0x10000 - ((UINTN) PrdBuffer & 0xFFFF);

      if (ByteCount <= ByteAvailable) {
        TempPrdAddr->RegionBaseAddr = (UINT32) ((UINTN) PrdBuffer);
        TempPrdAddr->ByteCount      = (UINT16) ByteCount;
        TempPrdAddr->EndOfTable     = 0x8000;
        break;
      }

      TempPrdAddr->RegionBaseAddr = (UINT32) ((UINTN) PrdBuffer);
      TempPrdAddr->ByteCount      = (UINT16) ByteAvailable;

      ByteCount -= ByteAvailable;
      PrdBuffer += ByteAvailable;
      TempPrdAddr++;
    }

    //
    // Set the base address to BMID register
    //
    IdeDev->PciIo->Io.Write (
                        IdeDev->PciIo,
                        EfiPciIoWidthUint32,
                        EFI_PCI_IO_PASS_THROUGH_BAR,
                        IoPortForBmid,
                        1,
                        &UsedPrdAddr
                        );

    //
    // Set BMIC register to identify the operation direction
    //
    IdeDev->PciIo->Io.Read (
                        IdeDev->PciIo,
                        EfiPciIoWidthUint8,
                        EFI_PCI_IO_PASS_THROUGH_BAR,
                        IoPortForBmic,
                        1,
                        &RegisterValue
                        );

    if (UdmaOp == AtaUdmaReadExtOp || UdmaOp == AtaUdmaReadOp) {
      RegisterValue |= BMIC_NREAD;
    } else {
      RegisterValue &= ~((UINT8) BMIC_NREAD);
    }

    IdeDev->PciIo->Io.Write (
                        IdeDev->PciIo,
                        EfiPciIoWidthUint8,
                        EFI_PCI_IO_PASS_THROUGH_BAR,
                        IoPortForBmic,
                        1,
                        &RegisterValue
                        );

    if (UdmaOp == AtaUdmaWriteExtOp || UdmaOp == AtaUdmaReadExtOp) {
      Status = AtaCommandIssueExt (
                 IdeDev,
                 AtaCommand,
                 Device,
                 0,
                 (UINT16) NumberOfBlocks,
                 StartLba
                 );
    } else {
      Status = AtaCommandIssue (
                 IdeDev,
                 AtaCommand,
                 Device,
                 0,
                 (UINT16) NumberOfBlocks,
                 StartLba
                 );
    }

    if (EFI_ERROR (Status)) {
      IdeDev->PciIo->FreeBuffer (IdeDev->PciIo, PageCount, MemPage);
      IdeDev->PciIo->Unmap (IdeDev->PciIo, Map);
      return EFI_DEVICE_ERROR;
    }

    //
    // Set START bit of BMIC register
    //
    IdeDev->PciIo->Io.Read (
                        IdeDev->PciIo,
                        EfiPciIoWidthUint8,
                        EFI_PCI_IO_PASS_THROUGH_BAR,
                        IoPortForBmic,
                        1,
                        &RegisterValue
                        );

    RegisterValue |= BMIC_START;

    IdeDev->PciIo->Io.Write (
                        IdeDev->PciIo,
                        EfiPciIoWidthUint8,
                        EFI_PCI_IO_PASS_THROUGH_BAR,
                        IoPortForBmic,
                        1,
                        &RegisterValue
                        );

    //
    // Check the INTERRUPT and ERROR bit of BMIS
    // Max transfer number of sectors for one command is 65536(32Mbyte),
    // it will cost 1 second to transfer these data in UDMA mode 2(33.3MBps).
    // So set the variable Count to 2000, for about 2 second timeout time.
    //
    Status = EFI_SUCCESS;
    Count = 2000;
    while (TRUE) {

      IdeDev->PciIo->Io.Read (
                          IdeDev->PciIo,
                          EfiPciIoWidthUint8,
                          EFI_PCI_IO_PASS_THROUGH_BAR,
                          IoPortForBmis,
                          1,
                          &RegisterValue
                          );
      if (((RegisterValue & (BMIS_INTERRUPT | BMIS_ERROR)) != 0) || (Count == 0)) {
        if (((RegisterValue & BMIS_ERROR) != 0) || (Count == 0)) {
		  Status = EFI_DEVICE_ERROR;
		  break;
        }
        break;
      }

      gBS->Stall (1000);
      Count --;
    }

    IdeDev->PciIo->FreeBuffer (IdeDev->PciIo, PageCount, MemPage);
    IdeDev->PciIo->Unmap (IdeDev->PciIo, Map);
    //
    // Read BMIS register and clear ERROR and INTR bit
    //
    IdeDev->PciIo->Io.Read (
                        IdeDev->PciIo,
                        EfiPciIoWidthUint8,
                        EFI_PCI_IO_PASS_THROUGH_BAR,
                        IoPortForBmis,
                        1,
                        &RegisterValue
                        );

    RegisterValue |= (BMIS_INTERRUPT | BMIS_ERROR);

    IdeDev->PciIo->Io.Write (
                        IdeDev->PciIo,
                        EfiPciIoWidthUint8,
                        EFI_PCI_IO_PASS_THROUGH_BAR,
                        IoPortForBmis,
                        1,
                        &RegisterValue
                        );
	//
    // Read Status Register of IDE device to clear interrupt
    //
    RegisterValue = IDEReadPortB(IdeDev->PciIo,IdeDev->IoPort->Reg.Status);
    //
    // Clear START bit of BMIC register
    //
    IdeDev->PciIo->Io.Read (
                        IdeDev->PciIo,
                        EfiPciIoWidthUint8,
                        EFI_PCI_IO_PASS_THROUGH_BAR,
                        IoPortForBmic,
                        1,
                        &RegisterValue
                        );

    RegisterValue &= ~((UINT8) BMIC_START);

    IdeDev->PciIo->Io.Write (
                        IdeDev->PciIo,
                        EfiPciIoWidthUint8,
                        EFI_PCI_IO_PASS_THROUGH_BAR,
                        IoPortForBmic,
                        1,
                        &RegisterValue
                        );

    if ((RegisterValue & BMIS_ERROR) != 0) {
      return EFI_DEVICE_ERROR;
    }

	if (EFI_ERROR (Status)) {
	  break;
	}
    DataBuffer = (UINT8 *) DataBuffer + NumberOfBlocks * IdeDev->BlkIo.Media->BlockSize;
    StartLba += NumberOfBlocks;
  }

  //
  // Disable interrupt of Select device
  //
  IDEReadPortB (IdeDev->PciIo, IdeDev->IoPort->Alt.DeviceControl);
  DeviceControl |= ATA_CTLREG_IEN_L;
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->Alt.DeviceControl, DeviceControl);

  return Status;
}


/**
  This function is called by the AtaBlkIoReadBlocks() to perform reading from
  media in block unit. The function has been enhanced to support >120GB access 
  and transfer at most 65536 blocks per command

  @param IdeDev         pointer pointing to IDE_BLK_IO_DEV data structure, used to record 
                        all the information of the IDE device.
  @param DataBuffer     A pointer to the destination buffer for the data.
  @param StartLba       The starting logical block address to read from on the device media.
  @param NumberOfBlocks The number of transfer data blocks.

  @return status depends on the function DoAtaUdma() returns.
**/
EFI_STATUS
AtaUdmaReadExt (
  IN  IDE_BLK_IO_DEV  *IdeDev,
  IN  VOID            *DataBuffer,
  IN  EFI_LBA         StartLba,
  IN  UINTN           NumberOfBlocks
  )
{
  return DoAtaUdma (IdeDev, DataBuffer, StartLba, NumberOfBlocks, AtaUdmaReadExtOp);
}
/**
  This function is called by the AtaBlkIoReadBlocks() to perform
  reading from media in block unit. The function has been enhanced to
  support >120GB access and transfer at most 65536 blocks per command

  @param IdeDev         pointer pointing to IDE_BLK_IO_DEV data structure, used to record
                        all the information of the IDE device.
  @param DataBuffer     A pointer to the destination buffer for the data.
  @param StartLba       The starting logical block address to read from
                        on the device media.
  @param NumberOfBlocks The number of transfer data blocks.
  
  @return status depends on the function DoAtaUdma() returns.
**/
EFI_STATUS
AtaUdmaRead (
  IN  IDE_BLK_IO_DEV  *IdeDev,
  IN  VOID            *DataBuffer,
  IN  EFI_LBA         StartLba,
  IN  UINTN           NumberOfBlocks
  )
{
  return DoAtaUdma (IdeDev, DataBuffer, StartLba, NumberOfBlocks, AtaUdmaReadOp);
}

/**
  This function is called by the AtaBlkIoReadBlocks() to perform
  reading from media in block unit. The function has been enhanced to
  support >120GB access and transfer at most 65536 blocks per command

  @param IdeDev         pointer pointing to IDE_BLK_IO_DEV data structure, used to record
                        all the information of the IDE device.
  @param DataBuffer     A pointer to the destination buffer for the data.
  @param StartLba       The starting logical block address to read from on the device media.
  @param NumberOfBlocks The number of transfer data blocks.

  @return status is fully dependent on the return status of AtaPioDataInExt() function.
**/
EFI_STATUS
AtaReadSectorsExt (
  IN  IDE_BLK_IO_DEV  *IdeDev,
  IN  VOID            *DataBuffer,
  IN  EFI_LBA         StartLba,
  IN  UINTN           NumberOfBlocks
  )
{
  EFI_STATUS  Status;
  UINTN       BlocksRemaining;
  EFI_LBA     Lba64;
  UINT8       AtaCommand;
  UINT16      SectorCount;
  UINT32      ByteCount;
  VOID        *Buffer;

  //
  // Using ATA "Read Sectors Ext" command(opcode=0x24) with PIO DATA IN protocol
  //
  AtaCommand      = ATA_CMD_READ_SECTORS_EXT;
  Buffer          = DataBuffer;
  BlocksRemaining = NumberOfBlocks;
  Lba64           = StartLba;
  Status          = EFI_SUCCESS;

  while (BlocksRemaining > 0) {

    if (BlocksRemaining >= 0x10000) {
      //
      //  SectorCount is used to record the number of sectors to be read
      //  Max 65536 sectors can be transfered at a time.
      //
      SectorCount = 0xffff;
    } else {
      SectorCount = (UINT16) BlocksRemaining;
    }

    //
    // ByteCount is the number of bytes that will be read
    //
    ByteCount = SectorCount * (IdeDev->BlkIo.Media->BlockSize);

    //
    // call AtaPioDataInExt() to send Read Sector Command and receive data read
    //
    Status = AtaPioDataInExt (
              IdeDev,
              Buffer,
              ByteCount,
              AtaCommand,
              Lba64,
              SectorCount
              );
    if (EFI_ERROR (Status)) {
      return Status;
    }

    Lba64 += SectorCount;
    Buffer = ((UINT8 *) Buffer + ByteCount);
    BlocksRemaining -= SectorCount;
  }

  return Status;
}
/**
  This function is the ATA implementation for ReadBlocks in the
  Block I/O Protocol interface.

  @param IdeBlkIoDevice Indicates the calling context.
  @param MediaId        The media id that the read request is for.
  @param Lba            The starting logical block address to read from on the device.
  @param BufferSize     The size of the Buffer in bytes. This must be a  multiple
                        of the intrinsic block size of the device.

  @param Buffer         A pointer to the destination buffer for the data. The caller
                        is responsible for either having implicit or explicit ownership
                        of the memory that data is read into.

  @retval EFI_SUCCESS          Read Blocks successfully.
  @retval EFI_DEVICE_ERROR     Read Blocks failed.
  @retval EFI_NO_MEDIA         There is no media in the device.
  @retval EFI_MEDIA_CHANGE     The MediaId is not for the current media.
  @retval EFI_BAD_BUFFER_SIZE  The BufferSize parameter is not a multiple of the
                               intrinsic block size of the device.
  @retval EFI_INVALID_PARAMETER  The read request contains LBAs that are not valid,
                                 or the data buffer is not valid.

  @note If Read Block error because of device error, this function will call
        AtaSoftReset() function to reset device.

**/
EFI_STATUS
AtaBlkIoReadBlocks (
  IN IDE_BLK_IO_DEV   *IdeBlkIoDevice,
  IN UINT32           MediaId,
  IN EFI_LBA          Lba,
  IN UINTN            BufferSize,
  OUT VOID            *Buffer
  )
{
  EFI_BLOCK_IO_MEDIA  *Media;
  UINTN               BlockSize;
  UINTN               NumberOfBlocks;
  EFI_STATUS          Status;

  if (Buffer == NULL) {
    return EFI_INVALID_PARAMETER;
  }

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

  Status = EFI_SUCCESS;

  //
  //  Get the intrinsic block size
  //
  Media           = IdeBlkIoDevice->BlkIo.Media;
  BlockSize       = Media->BlockSize;

  NumberOfBlocks  = BufferSize / BlockSize;

  if (MediaId != Media->MediaId) {
    return EFI_MEDIA_CHANGED;
  }

  if (BufferSize % BlockSize != 0) {
    return EFI_BAD_BUFFER_SIZE;
  }

  if (!(Media->MediaPresent)) {
    return EFI_NO_MEDIA;
  }

  if (Lba > Media->LastBlock) {
    return EFI_INVALID_PARAMETER;
  }

  if ((Lba + NumberOfBlocks - 1) > Media->LastBlock) {
    return EFI_INVALID_PARAMETER;
  }

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

  Status = EFI_SUCCESS;
  if (IdeBlkIoDevice->Type == Ide48bitAddressingHardDisk) {
    //
    // For ATA/ATAPI-6 device(capcity > 120GB), use ATA-6 read block mechanism
    //
    if (IdeBlkIoDevice->UdmaMode.Valid) {
      Status = AtaUdmaReadExt (IdeBlkIoDevice, Buffer, Lba, NumberOfBlocks);
    } else {
      Status = AtaReadSectorsExt (IdeBlkIoDevice, Buffer, Lba, NumberOfBlocks);
    }
  } else {
    //
    // For ATA-3 compatible device, use ATA-3 read block mechanism
    //
    if (IdeBlkIoDevice->UdmaMode.Valid) {
      Status = AtaUdmaRead (IdeBlkIoDevice, Buffer, Lba, NumberOfBlocks);
    } else {
      Status = AtaReadSectors (IdeBlkIoDevice, Buffer, Lba, NumberOfBlocks);
    }
  }

  if (EFI_ERROR (Status)) {
    AtaSoftReset (IdeBlkIoDevice);
    return EFI_DEVICE_ERROR;
  }

  return EFI_SUCCESS;

}
/**
  This function is used to send out ATA commands conforms to the
  PIO Data Out Protocol, supporting ATA/ATAPI-6 standard

  Comparing with ATA-3 data out protocol, we have two differents here:<BR>
  1. Do NOT wait for DRQ clear before sending command into IDE device.(the
  wait will frequently fail... cause writing function return error)

  2. Do NOT wait for DRQ clear after all data readed.(the wait greatly
  slow down writing performance by 100 times!)

  @param IdeDev       pointer pointing to IDE_BLK_IO_DEV data structure, used
                       to record all the information of the IDE device.
  @param Buffer       buffer contained data transferred from host to device.
  @param ByteCount    data size in byte unit of the buffer.
  @param AtaCommand   value of the Command Register
  @param StartLba     the start LBA of this transaction
  @param SectorCount  the count of sectors to be transfered

  @retval EFI_SUCCESS      send out the ATA command and device receive required
                           data successfully.
  @retval EFI_DEVICE_ERROR command sent failed.

**/
EFI_STATUS
AtaPioDataOutExt (
  IN  IDE_BLK_IO_DEV  *IdeDev,
  IN  VOID            *Buffer,
  IN  UINT32          ByteCount,
  IN  UINT8           AtaCommand,
  IN  EFI_LBA         StartLba,
  IN  UINT16          SectorCount
  )
{
  UINT8       DevSel;
  UINT8       SectorCount8;
  UINT8       LbaLow;
  UINT8       LbaMid;
  UINT8       LbaHigh;
  UINTN       WordCount;
  UINTN       Increment;
  UINT16      *Buffer16;
  EFI_STATUS  Status;

  Status = WaitForBSYClear (IdeDev, ATATIMEOUT);
  if (EFI_ERROR (Status)) {
    return EFI_DEVICE_ERROR;
  }

  //
  // Select device. Set bit6 as 1 to indicate LBA mode is used
  //
  DevSel = (UINT8) (IdeDev->Device << 4);
  DevSel |= 0x40;
  IDEWritePortB (
    IdeDev->PciIo,
    IdeDev->IoPort->Head,
    DevSel
    );

  //
  // Wait for DRDY singnal asserting.
  //
  Status = DRDYReady (IdeDev, ATATIMEOUT);
  if (EFI_ERROR (Status)) {
    return EFI_DEVICE_ERROR;
  }

  //
  // Fill feature register if needed
  //
  if (AtaCommand == ATA_CMD_SET_FEATURES) {
    IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->Reg1.Feature, 0x03);
  }

  //
  // Fill the sector count register, which is a two-byte FIFO. Need write twice.
  //
  SectorCount8 = (UINT8) (SectorCount >> 8);
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->SectorCount, SectorCount8);

  SectorCount8 = (UINT8) SectorCount;
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->SectorCount, SectorCount8);

  //
  // Fill the start LBA registers, which are also two-byte FIFO
  //
  LbaLow  = (UINT8) RShiftU64 (StartLba, 24);
  LbaMid  = (UINT8) RShiftU64 (StartLba, 32);
  LbaHigh = (UINT8) RShiftU64 (StartLba, 40);
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->SectorNumber, LbaLow);
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->CylinderLsb, LbaMid);
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->CylinderMsb, LbaHigh);

  LbaLow  = (UINT8) StartLba;
  LbaMid  = (UINT8) RShiftU64 (StartLba, 8);
  LbaHigh = (UINT8) RShiftU64 (StartLba, 16);
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->SectorNumber, LbaLow);
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->CylinderLsb, LbaMid);
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->CylinderMsb, LbaHigh);

  //
  // Send command via Command Register, invoking the processing of this command
  //
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->Reg.Command, AtaCommand);

  Buffer16 = (UINT16 *) Buffer;

  //
  // According to PIO Data Out protocol, host can perform a series of writes to
  // the data register after each time device set DRQ ready;
  //
  Increment = 256;

  //
  // used to record bytes of currently transfered data
  //
  WordCount = 0;

  while (WordCount < ByteCount / 2) {
    //
    // Poll DRQ bit set, data transfer can be performed only when DRQ is ready.
    //
    Status = DRQReady2 (IdeDev, ATATIMEOUT);
    if (EFI_ERROR (Status)) {
      return EFI_DEVICE_ERROR;
    }

    Status = CheckErrorStatus (IdeDev);
    if (EFI_ERROR (Status)) {
      return EFI_DEVICE_ERROR;
    }

    //
    // Write data into device by one series of writing to data register
    //
    if ((WordCount + Increment) > ByteCount / 2) {
      Increment = ByteCount / 2 - WordCount;
    }

    IDEWritePortWMultiple (
      IdeDev->PciIo,
      IdeDev->IoPort->Data,
      Increment,
      Buffer16
      );

    WordCount += Increment;
    Buffer16 += Increment;

  }
  return CheckErrorStatus (IdeDev);
}
/**
  This function is called by the AtaBlkIoWriteBlocks() to perform
  writing to media in block unit. The function has been enhanced to
  support >120GB access and transfer at most 65536 blocks per command

  @param IdeDev         pointer pointing to IDE_BLK_IO_DEV data structure, used
                        to record all the information of the IDE device.
  @param DataBuffer     A pointer to the source buffer for the data.
  @param StartLba       The starting logical block address to write to
                        on the device media.
  @param NumberOfBlocks The number of transfer data blocks.

  @return status depends on the function DoAtaUdma() returns.
**/
EFI_STATUS
AtaUdmaWriteExt (
  IN  IDE_BLK_IO_DEV  *IdeDev,
  IN  VOID            *DataBuffer,
  IN  EFI_LBA         StartLba,
  IN  UINTN           NumberOfBlocks
  )
{
  return DoAtaUdma (IdeDev, DataBuffer, StartLba, NumberOfBlocks, AtaUdmaWriteExtOp);
}

/**
  This function is called by the AtaBlkIoWriteBlocks() to perform
  writing to media in block unit. 

  @param IdeDev         pointer pointing to IDE_BLK_IO_DEV data structure, used
                        to record all the information of the IDE device.
  @param DataBuffer     A pointer to the source buffer for the data.
  @param StartLba       The starting logical block address to write to
                        on the device media.
  @param NumberOfBlocks The number of transfer data blocks.
  
  @return status depends on the function DoAtaUdma() returns.
**/
EFI_STATUS
AtaUdmaWrite (
  IN  IDE_BLK_IO_DEV  *IdeDev,
  IN  VOID            *DataBuffer,
  IN  EFI_LBA         StartLba,
  IN  UINTN           NumberOfBlocks
  )
{
  return DoAtaUdma (IdeDev, DataBuffer, StartLba, NumberOfBlocks, AtaUdmaWriteOp);
}
/**
  This function is called by the AtaBlkIoWriteBlocks() to perform
  writing onto media in block unit. The function has been enhanced to
  support >120GB access and transfer at most 65536 blocks per command

  @param IdeDev         pointer pointing to IDE_BLK_IO_DEV data structure,used
                        to record all the information of the IDE device.
  @param DataBuffer     A pointer to the source buffer for the data.
  @param StartLba       The starting logical block address to write onto the device 
                        media.
  @param NumberOfBlocks The number of transfer data blocks.

  @return status is fully dependent on the return status of AtaPioDataOutExt() function.
**/
EFI_STATUS
AtaWriteSectorsExt (
  IN  IDE_BLK_IO_DEV  *IdeDev,
  IN  VOID            *DataBuffer,
  IN  EFI_LBA         StartLba,
  IN  UINTN           NumberOfBlocks
  )
{
  EFI_STATUS  Status;
  EFI_LBA     Lba64;
  UINTN       BlocksRemaining;
  UINT8       AtaCommand;
  UINT16      SectorCount;
  UINT32      ByteCount;
  VOID        *Buffer;

  //
  // Using ATA "Write Sectors Ext" cmd(opcode=0x24) with PIO DATA OUT protocol
  //
  AtaCommand      = ATA_CMD_WRITE_SECTORS_EXT;
  Lba64           = StartLba;
  Buffer          = DataBuffer;
  BlocksRemaining = NumberOfBlocks;

  Status          = EFI_SUCCESS;

  while (BlocksRemaining > 0) {

    if (BlocksRemaining >= 0x10000) {
      //
      //  SectorCount is used to record the number of sectors to be written.
      //  Max 65536 sectors can be transfered at a time.
      //
      SectorCount = 0xffff;
    } else {
      SectorCount = (UINT16) BlocksRemaining;
    }

    //
    // ByteCount is the number of bytes that will be written
    //
    ByteCount = SectorCount * (IdeDev->BlkIo.Media->BlockSize);

    //
    // Call AtaPioDataOutExt() to send "Write Sectors Ext" Command
    //
    Status = AtaPioDataOutExt (
              IdeDev,
              Buffer,
              ByteCount,
              AtaCommand,
              Lba64,
              SectorCount
              );
    if (EFI_ERROR (Status)) {
      return Status;
    }

    Lba64 += SectorCount;
    Buffer = ((UINT8 *) Buffer + ByteCount);
    BlocksRemaining -= SectorCount;
  }

  return Status;
}
/**
  This function is the ATA implementation for WriteBlocks in the
  Block I/O Protocol interface.

  @param IdeBlkIoDevice  Indicates the calling context.
  @param MediaId         The media id that the write request is for.
  @param Lba             The starting logical block address to write onto the device.
  @param BufferSize      The size of the Buffer in bytes. This must be a multiple
                         of the intrinsic block size of the device.
  @param Buffer          A pointer to the source buffer for the data.The caller
                         is responsible for either having implicit or explicit 
                         ownership of the memory that data is written from.

  @retval EFI_SUCCESS       Write Blocks successfully.
  @retval EFI_DEVICE_ERROR  Write Blocks failed.
  @retval EFI_NO_MEDIA      There is no media in the device.
  @retval EFI_MEDIA_CHANGE  The MediaId is not for the current media.

  @retval EFI_BAD_BUFFER_SIZE   The BufferSize parameter is not a multiple of the
                                intrinsic block size of the device.
  @retval EFI_INVALID_PARAMETER The write request contains LBAs that are not valid,
                                or the data buffer is not valid.

  @note If Write Block error because of device error, this function will call
        AtaSoftReset() function to reset device.
**/
EFI_STATUS
AtaBlkIoWriteBlocks (
  IN  IDE_BLK_IO_DEV   *IdeBlkIoDevice,
  IN  UINT32           MediaId,
  IN  EFI_LBA          Lba,
  IN  UINTN            BufferSize,
  OUT VOID             *Buffer
  )
{

  EFI_BLOCK_IO_MEDIA  *Media;
  UINTN               BlockSize;
  UINTN               NumberOfBlocks;
  EFI_STATUS          Status;

  if (Buffer == NULL) {
    return EFI_INVALID_PARAMETER;
  }

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

  Status = EFI_SUCCESS;

  //
  // Get the intrinsic block size
  //
  Media           = IdeBlkIoDevice->BlkIo.Media;
  BlockSize       = Media->BlockSize;
  NumberOfBlocks  = BufferSize / BlockSize;

  if (MediaId != Media->MediaId) {
    return EFI_MEDIA_CHANGED;
  }

  if (BufferSize % BlockSize != 0) {
    return EFI_BAD_BUFFER_SIZE;
  }

  if (Lba > Media->LastBlock) {
    return EFI_INVALID_PARAMETER;
  }

  if ((Lba + NumberOfBlocks - 1) > Media->LastBlock) {
    return EFI_INVALID_PARAMETER;
  }

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

  Status = EFI_SUCCESS;
  if (IdeBlkIoDevice->Type == Ide48bitAddressingHardDisk) {
    //
    // For ATA/ATAPI-6 device(capcity > 120GB), use ATA-6 write block mechanism
    //
    if (IdeBlkIoDevice->UdmaMode.Valid) {
      Status = AtaUdmaWriteExt (IdeBlkIoDevice, Buffer, Lba, NumberOfBlocks);
    } else {
      Status = AtaWriteSectorsExt (IdeBlkIoDevice, Buffer, Lba, NumberOfBlocks);
    }
  } else {
    //
    // For ATA-3 compatible device, use ATA-3 write block mechanism
    //
    if (IdeBlkIoDevice->UdmaMode.Valid) {
      Status = AtaUdmaWrite (IdeBlkIoDevice, Buffer, Lba, NumberOfBlocks);
    } else {
      Status = AtaWriteSectors (IdeBlkIoDevice, Buffer, Lba, NumberOfBlocks);
    }
  }

  if (EFI_ERROR (Status)) {
    AtaSoftReset (IdeBlkIoDevice);
    return EFI_DEVICE_ERROR;
  }

  return EFI_SUCCESS;
}
/**
  Enable Long Physical Sector Feature for ATA device.

  @param   IdeDev  The IDE device data

  @retval  EFI_SUCCESS      The ATA device supports Long Physical Sector feature
                            and corresponding fields in BlockIo structure is updated.
  @retval  EFI_UNSUPPORTED  The device is not ATA device or Long Physical Sector
                            feature is not supported.
**/
EFI_STATUS
AtaEnableLongPhysicalSector (
  IN  IDE_BLK_IO_DEV  *IdeDev
  )
{
  EFI_ATA_IDENTIFY_DATA  *AtaIdentifyData;
  UINT16                 PhyLogicSectorSupport;

  ASSERT (IdeDev->IdData != NULL);
  //
  // Only valid for ATA device
  //
  AtaIdentifyData       = (EFI_ATA_IDENTIFY_DATA *) &IdeDev->IdData->AtaData;
  if ((AtaIdentifyData->config & 0x8000) != 0) {
    return EFI_UNSUPPORTED;
  }
  PhyLogicSectorSupport = AtaIdentifyData->phy_logic_sector_support;
  //
  // Check whether Long Physical Sector Feature is supported
  //
  if ((PhyLogicSectorSupport & 0xc000) == 0x4000) {
    IdeDev->BlkIo.Media->LogicalBlocksPerPhysicalBlock = 1;
    IdeDev->BlkIo.Media->LowestAlignedLba              = 0;
    //
    // Check whether one physical block contains multiple physical blocks
    //
    if ((PhyLogicSectorSupport & 0x2000) != 0) {
      IdeDev->BlkIo.Media->LogicalBlocksPerPhysicalBlock =
        (UINT32) (1 << (PhyLogicSectorSupport & 0x000f));
      //
      // Check lowest alignment of logical blocks within physical block
      //
      if ((AtaIdentifyData->alignment_logic_in_phy_blocks & 0xc000) == 0x4000) {
        IdeDev->BlkIo.Media->LowestAlignedLba =
          (EFI_LBA) ((IdeDev->BlkIo.Media->LogicalBlocksPerPhysicalBlock - ((UINT32)AtaIdentifyData->alignment_logic_in_phy_blocks & 0x3fff)) %
          IdeDev->BlkIo.Media->LogicalBlocksPerPhysicalBlock);
      }
    }
    //
    // Check logical block size
    //
    IdeDev->BlkIo.Media->BlockSize = 0x200;
    if ((PhyLogicSectorSupport & 0x1000) != 0) {
      IdeDev->BlkIo.Media->BlockSize = (UINT32) (
        ((AtaIdentifyData->logic_sector_size_hi << 16) |
         AtaIdentifyData->logic_sector_size_lo) * sizeof (UINT16)
        );
    }
    return EFI_SUCCESS;
  } else {
    return EFI_UNSUPPORTED;
  }
}
/**
  Send ATA command into device with NON_DATA protocol

  @param  IdeDev Standard IDE device private data structure
  @param  AtaCommand The ATA command to be sent
  @param  Device The value in Device register
  @param  Feature The value in Feature register
  @param  SectorCount The value in SectorCount register
  @param  LbaLow The value in LBA_LOW register
  @param  LbaMiddle The value in LBA_MIDDLE register
  @param  LbaHigh The value in LBA_HIGH register

  @retval  EFI_SUCCESS Reading succeed
  @retval  EFI_ABORTED Command failed
  @retval  EFI_DEVICE_ERROR Device status error.

**/
EFI_STATUS
AtaNonDataCommandIn (
  IN  IDE_BLK_IO_DEV  *IdeDev,
  IN  UINT8           AtaCommand,
  IN  UINT8           Device,
  IN  UINT8           Feature,
  IN  UINT8           SectorCount,
  IN  UINT8           LbaLow,
  IN  UINT8           LbaMiddle,
  IN  UINT8           LbaHigh
  )
{
  EFI_STATUS  Status;
  UINT8       StatusRegister;

  Status = WaitForBSYClear (IdeDev, ATATIMEOUT);
  if (EFI_ERROR (Status)) {
    return EFI_DEVICE_ERROR;
  }

  //
  // Select device (bit4), set Lba mode(bit6) (use 0xe0 for compatibility)
  //
  IDEWritePortB (
    IdeDev->PciIo,
    IdeDev->IoPort->Head,
    (UINT8) ((IdeDev->Device << 4) | 0xe0)
    );

  //
  // ATA commands for ATA device must be issued when DRDY is set
  //
  Status = DRDYReady (IdeDev, ATATIMEOUT);
  if (EFI_ERROR (Status)) {
    return EFI_DEVICE_ERROR;
  }

  //
  // Pass parameter into device register block
  //
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->Head, Device);
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->Reg1.Feature, Feature);
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->SectorCount, SectorCount);
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->SectorNumber, LbaLow);
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->CylinderLsb, LbaMiddle);
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->CylinderMsb, LbaHigh);

  //
  // Send command via Command Register
  //
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->Reg.Command, AtaCommand);

  //
  // Wait for command completion
  // For ATAPI_SMART_CMD, we may need more timeout to let device
  // adjust internal states.
  //
  if (AtaCommand == ATA_CMD_SMART) {
    Status = WaitForBSYClear (IdeDev, ATASMARTTIMEOUT);
  } else {
    Status = WaitForBSYClear (IdeDev, ATATIMEOUT);
  }
  if (EFI_ERROR (Status)) {
    return EFI_DEVICE_ERROR;
  }

  StatusRegister = IDEReadPortB (IdeDev->PciIo, IdeDev->IoPort->Reg.Status);
  if ((StatusRegister & ATA_STSREG_ERR) == ATA_STSREG_ERR) {
    //
    // Failed to execute command, abort operation
    //
    return EFI_ABORTED;
  }

  return EFI_SUCCESS;
}

/**
  Send ATA Ext command into device with NON_DATA protocol

  @param  IdeDev Standard IDE device private data structure
  @param  AtaCommand The ATA command to be sent
  @param  Device The value in Device register
  @param  Feature The value in Feature register
  @param  SectorCount The value in SectorCount register
  @param  LbaAddress The LBA address in 48-bit mode

  @retval  EFI_SUCCESS Reading succeed
  @retval  EFI_ABORTED Command failed
  @retval  EFI_DEVICE_ERROR Device status error.

**/
EFI_STATUS
AtaNonDataCommandInExt (
  IN  IDE_BLK_IO_DEV  *IdeDev,
  IN  UINT8           AtaCommand,
  IN  UINT8           Device,
  IN  UINT16          Feature,
  IN  UINT16          SectorCount,
  IN  EFI_LBA         LbaAddress
  )
{
  EFI_STATUS  Status;
  UINT8       StatusRegister;
  UINT8       SectorCount8;
  UINT8       Feature8;
  UINT8       LbaLow;
  UINT8       LbaMid;
  UINT8       LbaHigh;

  Status = WaitForBSYClear (IdeDev, ATATIMEOUT);
  if (EFI_ERROR (Status)) {
    return EFI_DEVICE_ERROR;
  }

  //
  // Select device (bit4), set LBA mode(bit6) (use 0xe0 for compatibility)
  //
  IDEWritePortB (
    IdeDev->PciIo,
    IdeDev->IoPort->Head,
    (UINT8) ((IdeDev->Device << 4) | 0xe0)
    );

  //
  // ATA commands for ATA device must be issued when DRDY is set
  //
  Status = DRDYReady (IdeDev, ATATIMEOUT);
  if (EFI_ERROR (Status)) {
    return EFI_DEVICE_ERROR;
  }

  //
  // Pass parameter into device register block
  //
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->Head, Device);

  //
  // Fill the feature register, which is a two-byte FIFO. Need write twice.
  //
  Feature8 = (UINT8) (Feature >> 8);
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->Reg1.Feature, Feature8);

  Feature8 = (UINT8) Feature;
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->Reg1.Feature, Feature8);

  //
  // Fill the sector count register, which is a two-byte FIFO. Need write twice.
  //
  SectorCount8 = (UINT8) (SectorCount >> 8);
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->SectorCount, SectorCount8);

  SectorCount8 = (UINT8) SectorCount;
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->SectorCount, SectorCount8);

  //
  // Fill the start LBA registers, which are also two-byte FIFO
  //
  LbaLow  = (UINT8) RShiftU64 (LbaAddress, 24);
  LbaMid  = (UINT8) RShiftU64 (LbaAddress, 32);
  LbaHigh = (UINT8) RShiftU64 (LbaAddress, 40);
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->SectorNumber, LbaLow);
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->CylinderLsb, LbaMid);
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->CylinderMsb, LbaHigh);

  LbaLow  = (UINT8) LbaAddress;
  LbaMid  = (UINT8) RShiftU64 (LbaAddress, 8);
  LbaHigh = (UINT8) RShiftU64 (LbaAddress, 16);
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->SectorNumber, LbaLow);
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->CylinderLsb, LbaMid);
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->CylinderMsb, LbaHigh);

  //
  // Send command via Command Register
  //
  IDEWritePortB (IdeDev->PciIo, IdeDev->IoPort->Reg.Command, AtaCommand);

  //
  // Wait for command completion
  //
  Status = WaitForBSYClear (IdeDev, ATATIMEOUT);
  if (EFI_ERROR (Status)) {
    return EFI_DEVICE_ERROR;
  }

  StatusRegister = IDEReadPortB (IdeDev->PciIo, IdeDev->IoPort->Reg.Status);
  if ((StatusRegister & ATA_STSREG_ERR) == ATA_STSREG_ERR) {
    //
    // Failed to execute command, abort operation
    //
    return EFI_ABORTED;
  }

  return EFI_SUCCESS;
}