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How can a driver without hardware create two COM devices RRS feed

  • Question

  • When I install the virtualserial sample driver, one COM device is created. No hardware is needed.
    How can I modify this driver so that its installation creates two COM devices with identical functionality?
    Friday, November 14, 2014 8:03 AM

Answers

  • you need to debug the code 10 . the prescribed way is to install two root enumerated com ports in your case

    d -- This posting is provided "AS IS" with no warranties, and confers no rights.

    Thursday, July 7, 2016 3:50 PM

All replies

  • This driver is illustrative, and is not meant for production use. However, you can create an additional serial device the same way you created the first one. The serial driver creates an FDO that sits on top of a PDO generated by the toaster bus driver. Thus, you don't need to modify the serial driver, just cause the bus driver to squirt out another PDO.

     -Brian


    Azius Developer Training www.azius.com Windows device driver, internals, security, & forensics training and consulting. Blog at www.azius.com/blog

    Saturday, November 15, 2014 12:57 AM
    Moderator
  • you don't even need the bus driver to create another one. the virtual serial driver is root enumerated, just install another root enumerated device.

    d -- This posting is provided "AS IS" with no warranties, and confers no rights.

    Sunday, November 16, 2014 3:33 AM
  • On Windows 7 I can install the driver twice and I get two working COM-ports.

    On Windows 10, a second device can be installed but does not work. The device manager shows the error message "The device could not be started (Code 10)".

    How can I get two COM-ports on Windows 10? 
    Do I need the toaster bus driver?
    If so, how can I get it to "squirt out" another PDO?
    Thursday, July 7, 2016 10:06 AM
  • you need to debug the code 10 . the prescribed way is to install two root enumerated com ports in your case

    d -- This posting is provided "AS IS" with no warranties, and confers no rights.

    Thursday, July 7, 2016 3:50 PM
  • Hi Doron,

    thanks for your fast answer.

    The real reason for the problem is probably that I used WDK 8.0 which miraculously works even on Windows 10 when I install my driver once, but not when I install it twice (because WDK 8.0 has not been released for Windows 10).

    Monday, July 18, 2016 8:45 AM