library GetDiskSN;


{ Important note about DLL memory management: ShareMem must be the
  first unit in your library's USES clause AND your project's (select
  Project-View Source) USES clause if your DLL exports any procedures or
  functions that pass strings as parameters or function results. This
  applies to all strings passed to and from your DLL--even those that
  are nested in records and classes. ShareMem is the interface unit to
  the BORLNDMM.DLL shared memory manager, which must be deployed along
  with your DLL. To avoid using BORLNDMM.DLL, pass string information
  using PChar or ShortString parameters. }


uses
  SysUtils,
  Classes,
  Windows;


{$R *.res}
function GetIdeSerialNumber: PChar;
const
  IDENTIFY_BUFFER_SIZE = 512;
type
  TIDERegs = packed record
    bFeaturesReg: Byte;     // Used for specifying SMART "commands".
    bSectorCountReg: Byte;  // IDE sector count register
    bSectorNumberReg: Byte; // IDE sector number register
    bCylLowReg: Byte;       // IDE low order cylinder value
    bCylHighReg: Byte;      // IDE high order cylinder value
    bDriveHeadReg: Byte;    // IDE drive/head register
    bCommandReg: Byte;      // Actual IDE command.
    bReserved: Byte;        // reserved for future use. Must be zero.
  end;
  TSendCmdInParams = packed record
    // Buffer size in bytes
    cBufferSize: Longword;
    // Structure with drive register values.
    irDriveRegs: TIDERegs;
    // Physical drive number to send command to (0,1,2,3).
    bDriveNumber: Byte;
    bReserved: array[0..2] of Byte;
    dwReserved: array[0..3] of Longword;
    bBuffer: array[0..0] of Byte; // Input buffer.
  end;
  TIdSector = packed record
    wGenConfig: Word;
    wNumCyls: Word;
    wReserved: Word;
    wNumHeads: Word;
    wBytesPerTrack: Word;
    wBytesPerSector: Word;
    wSectorsPerTrack: Word;
    wVendorUnique: array[0..2] of Word;
    sSerialNumber: array[0..19] of Char;
    wBufferType: Word;
    wBufferSize: Word;
    wECCSize: Word;
    sFirmwareRev: array[0..7] of Char;
    sModelNumber: array[0..39] of Char;
    wMoreVendorUnique: Word;
    wDoubleWordIO: Word;
    wCapabilities: Word;
    wReserved1: Word;
    wPIOTiming: Word;
    wDMATiming: Word;
    wBS: Word;
    wNumCurrentCyls: Word;
    wNumCurrentHeads: Word;
    wNumCurrentSectorsPerTrack: Word;
    ulCurrentSectorCapacity: Longword;
    wMultSectorStuff: Word;
    ulTotalAddressableSectors: Longword;
    wSingleWordDMA: Word;
    wMultiWordDMA: Word;
    bReserved: array[0..127] of Byte;
  end;
  PIdSector     = ^TIdSector;
  TDriverStatus = packed record
    // 驅動器返回的錯誤程式碼，無錯則返回0
    bDriverError: Byte;
    // IDE出錯暫存器的內容，只有當bDriverError 為 SMART_IDE_ERROR 時有效
    bIDEStatus: Byte;
    bReserved: array[0..1] of Byte;
    dwReserved: array[0..1] of Longword;
  end;
  TSendCmdOutParams = packed record
    // bBuffer的大小
    cBufferSize: Longword;
    // 驅動器狀態
    DriverStatus: TDriverStatus;
    // 用於儲存從驅動器讀出的資料的緩衝區，實際長度由cBufferSize決定
    bBuffer: array[0..0] of Byte;
  end;
var
  hDevice: THandle;
  cbBytesReturned: Longword;
  SCIP: TSendCmdInParams;
  aIdOutCmd: array[0..(SizeOf(TSendCmdOutParams) + IDENTIFY_BUFFER_SIZE - 1) - 1] of
    Byte;
  IdOutCmd: TSendCmdOutParams absolute aIdOutCmd;
  procedure ChangeByteOrder(var Data; Size: Integer);
  var
    Ptr: PChar;
    i: Integer;
    c: Char;
  begin
    Ptr := @Data;
    for I := 0 to (Size shr 1) - 1 do
    begin
      c          := Ptr^;
      Ptr^       := (Ptr + 1)^;
      (Ptr + 1)^ := c;
      Inc(Ptr, 2);
    end;
  end;
begin
  Result := ''; // 如果出錯則返回空串
  if SysUtils.Win32Platform = VER_PLATFORM_WIN32_NT then
  begin // Windows NT, Windows 2000
        // 提示! 改變名稱可適用於其它驅動器，如第二個驅動器： '\\.\PhysicalDrive1\'
    hDevice := CreateFile('\\.\PhysicalDrive0', GENERIC_READ or GENERIC_WRITE,
      FILE_SHARE_READ or FILE_SHARE_WRITE, nil, OPEN_EXISTING, 0, 0);
  end
  else // Version Windows 95 OSR2, Windows 98
    hDevice := CreateFile('\\.\SMARTVSD', 0, 0, nil, CREATE_NEW, 0, 0);
  if hDevice = INVALID_HANDLE_VALUE then
    Exit;
  try
    FillChar(SCIP, SizeOf(TSendCmdInParams) - 1, #0);
    FillChar(aIdOutCmd, SizeOf(aIdOutCmd), #0);
    cbBytesReturned := 0;
    // Set up data structures for IDENTIFY command.
    with SCIP do
    begin
      cBufferSize := IDENTIFY_BUFFER_SIZE;
      // bDriveNumber := 0;
      with irDriveRegs do
      begin
        bSectorCountReg := 1;
        bSectorNumberReg := 1;
        // if Win32Platform=VER_PLATFORM_WIN32_NT then bDriveHeadReg := $A0
        // else bDriveHeadReg := $A0 or ((bDriveNum and 1) shl 4);
        bDriveHeadReg := $A0;
        bCommandReg := $EC;
      end;
    end;
    if not DeviceIoControl(hDevice, $0007C088, @SCIP,
      SizeOf(TSendCmdInParams) - 1, @aIdOutCmd, SizeOf(aIdOutCmd),
      cbBytesReturned, nil) then
      Exit;
  finally
    CloseHandle(hDevice);
  end;
  with PIdSector(@IdOutCmd.bBuffer)^ do
  begin
    ChangeByteOrder(sSerialNumber, SizeOf(sSerialNumber));
    (PChar(@sSerialNumber) + SizeOf(sSerialNumber))^ := #0;
    Result := PChar(@sSerialNumber);
  end;
end;
exports
GetIdeSerialNumber index 1;
begin
end.