none
Miniport driver for Serial device

    Question

  • Hi

    Earlier I was develope Miniport driver for "Network model control device" using USB interface.
    Is it possible to develope same kind of Miniport driver for UART serial device( UE connected via USB to the host machine)?
    For this developement is it enough to modify only lower end of USB functionality of miniport driver?
    Serial device loading 2 drivers(serialenum.sys, serial.sys), how to it applicable for my scenario?

    Thanks in advance.



    • Edited by Avata_ Monday, May 13, 2019 2:20 PM
    Monday, May 13, 2019 2:20 PM

All replies

  • Serial devices do not have a miniport model.  specifically for a usb connected serial device you should use the in box driver usbser.sys.  Serial.sys is the driver for a 16550 UART device (traditionally enumerated by the ISA bus, not USB)>.  serenum.sys is a serial port upper filter that enumerates devices connected to the serial port.  serenum.sys does not know how the serial port is connected to the host, it just opens the serial port like any other application would do and runs the detection protocol.

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

    Monday, May 13, 2019 4:10 PM
  • Thank you. sorry we are not using ISA bus. we using FTDI chip in our device. which is converts USB to serial. So our device project as usb bus device. FTDI also provided driver for that. Instead of FTDI driver is it possible to change my driver act as network miniport driver. FTDI they mention as virtual com port driver.

    driver location:

    https://www.ftdichip.com/Drivers/VCP.htm

    So Is it possible to write , Miniport driver for physical usb virtual com ?





    • Edited by Avata_ Monday, May 13, 2019 5:23 PM
    Monday, May 13, 2019 5:22 PM
  • IIRC there was a Microsoft's example of NDIS minport which is an upper filter on other device.

    You can do same over the FTDI custom driver,

    You will need to know how to talk to the FTDI driver. Or write your own, instead of provided by FTDI.

    -- pa

    Monday, May 13, 2019 9:18 PM
  • What on earth are you actually trying to do?  What is the end goal?

    Given a serial port, it is POSSIBLE to run a protocol like PPP or SLIP to provide an Ethernet connection.  That's what millions of us did before broadband connection to the house.  Our serial ports connected to modems that dialed into an Internet provider (e.g., AOL).  Is that what you're trying to do?  Because there are better ways to do that today.


    Tim Roberts | Driver MVP Emeritus | Providenza & Boekelheide, Inc.

    Tuesday, May 14, 2019 6:31 AM