USBDescriptoren einer Cypress-USB-Geräts auslesen

[dj9nmh]

So also an den DeviceDescriptor komme ich mittlerweile ran. Dies funktioniert über ein DeviceIOControl mit Control_Transfer. Beim StringDescriptor bin ich noch am testen.
Könnte es sein, dass dies der Standard-Weg ist an den Descriptor ranzukommen?
Ich kopiere mal die interessanten Zeilen aus meinem Testquellcode raus, evtl hat ja irgendjemand mal Nutzen davon:

Habe den Quellcode mit dem CyPress-Driver (CyUSB.sys Version 1.07.0000.0 Release) aus dem USBDevStudio benutzt, welches es auf cypress.com zum download gibt.

Delphi-Quellcode:

type
  SETUP_PACKET = packed record
    bmRequest : UChar;
    bRequest  : UChar;
    wValue    : WORD;
    wIndex    : WORD;
    wLength   : WORD;
    ulTimeOut : ULong;
  end;

  SINGLE_TRANSFER = packed record
    SetupPacket       : SETUP_PACKET;
    WaitForever       : UChar;
    ucEndpointAddress : UChar;
    NtStatus          : ULong;
    UsbdStatus        : ULong;
    IsoPacketOffset   : ULong;
    IsoPacketLength   : ULong;
    BufferOffset      : ULong;
    BufferLength      : ULong;
  end;

Delphi-Quellcode:

  const
    METHOD_BUFFERED   =   0;
    METHOD_IN_DIRECT  =   1;
    METHOD_OUT_DIRECT =   2;
    METHOD_NEITHER    =   3;


    FILE_ANY_ACCESS   =       0;
    FILE_READ_ACCESS  =   $0001;
    FILW_WRITE_ACCESS =   $0002;
    FILE_DEVICE_UNKNOWN: DEVICE_TYPE = $0C0000022;

Delphi-Quellcode:

  var
    DeviceHandle : THandle;
    Success : Boolean;
    nBytes: LongWord;
    IOCTL_ADAPT_SEND_EP0_CONTROL_TRANSFER : DWord;
    Buffer : Array[0..1023] of Byte;  // hier kleineren Buffer wählen
    SingleTransfer : SINGLE_TRANSFER;
    BufferLen : Integer;

Delphi-Quellcode:

  BufferLen := SizeOf(USB_DEVICE_DESCRIPTOR);
  SingleTransfer.SetupPacket.bmRequest := $00;
  SingleTransfer.SetupPacket.bRequest := 6;
  SingleTransfer.SetupPacket.wValue := $0100;

  SingleTransfer.SetupPacket.wIndex := $0000;

  SingleTransfer.SetupPacket.wLength := BufferLen;
  SingleTransfer.SetupPacket.ulTimeOut := 1000;

  SingleTransfer.WaitForever := 0;

  SingleTransfer.ucEndpointAddress := $00;
  SingleTransfer.IsoPacketLength := 0;
  SingleTransfer.BufferOffset := SizeOf(SINGLE_TRANSFER);
  SingleTransfer.BufferLength := BufferLen;

Delphi-Quellcode:

  IOCTL_ADAPT_SEND_EP0_CONTROL_TRANSFER := CTL_CODE(FILE_DEVICE_UNKNOWN,
                                                    8,
                                                    METHOD_BUFFERED,
                                                    FILE_ANY_ACCESS);

  //DeviceHandle bekommt man über ein CreateFile des Devices
  success := DeviceIoControl(DeviceHandle,
                             IOCTL_ADAPT_SEND_EP0_CONTROL_TRANSFER,
                             @SingleTransfer,
                             SizeOf(SINGLE_TRANSFER) + BufferLen,
                             @Buffer,
                             SizeOf(Buffer),
                             nBytes,
                             NIL);

  // in die DescriptorStruktur kopieren
  Move(Buffer[38], DC, SizeOf(DC));

Delphi-Quellcode:

  function TForm1.CTL_CODE (Devicetype: DWord; Func, Method, Access: Word) : DWord;
    begin
      CTL_CODE := (Devicetype shl 16) OR (Access shl 14) Or (Func shl 2) Or Method;
  end;