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Question regarding HID over I2C & Pointer device RRS feed

  • Question

  • I am working on Pointer device to be of type HIDI2C where I am trying to return feature report.

    In document "windows-pointer-device-protocol.docx", it is mentioned in section " Touch Hardware Quality Assurance", that device manufacturer needs to make sure to add space of 256 bytes of blob to store cryptographically signed binary blob. As we are in start of development of device phase, do we need to provide this space for 256 bytes. If so what shall data we provide in this feature report as we are yet in development.

    This is regarding "Vendor Defined Usage Page" in report descriptor.

    Kindly let me know.

    Monday, December 10, 2012 12:33 PM

Answers

  • This is documented in the Windows 8 digitizers whitepaper on MSDN.   The space needs to be provided and could be filled with a sample blob as outlined in the whitepaper. 

    During development you can try out your implementation without a certification blob by booting in test signing mode.  The system will not attempt to verify the THQA blob in test signing mode, hence touch should work even if the digitizer hasn’t been certified.

    The sample blob will never succeed for authentication and is only used for validation in a logo submission. Once a submission has been approved with the sample blob, a genuine blob shall be issued which will allow authentication without test-signing mode.

    Saturday, December 15, 2012 9:39 PM

All replies

  • This is documented in the Windows 8 digitizers whitepaper on MSDN.   The space needs to be provided and could be filled with a sample blob as outlined in the whitepaper. 

    During development you can try out your implementation without a certification blob by booting in test signing mode.  The system will not attempt to verify the THQA blob in test signing mode, hence touch should work even if the digitizer hasn’t been certified.

    The sample blob will never succeed for authentication and is only used for validation in a logo submission. Once a submission has been approved with the sample blob, a genuine blob shall be issued which will allow authentication without test-signing mode.

    Saturday, December 15, 2012 9:39 PM
  • Thanks Jonsc. It solves my doubt.
    Wednesday, December 26, 2012 5:12 AM
  • Hi Johsc,

    I have another doubt. Does touch device (touch screen) has to be HID over I2C for Windows 8 and Windows RT?

    Can it be different driver using different transport?

    A different driver directly registering with windows HID framework and using another transport to communicate HID reports to Windows?

    Also as it is touch screen driver, will multitouch supported if we follow this approach? (I mean multitouch supported if it is not HID over I2C)

    Thanks.

    Monday, January 21, 2013 9:44 AM