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PDO creation in Virtual driver RRS feed

  • Question

  • Hi Experts,

    As per my understanding consider the KMDF driver is created and deployed. The PDO will be created by bus driver when the device is detected by the PnP manager. Then followed by it the driver will get loaded. In case of virtual COM port driver sample given, the PDO is created virtually when the driver is deployed.

    When the PDO will be created in case of virtual drivers and who creates it ?


    lyf4sci

    Tuesday, September 9, 2014 12:21 PM

Answers

  • A bus driver for a virtual device creates the PDO usually in response to some external event, often a DeviceIoControl IRP, but it could be anything including creating the PDOs automatically when the bus driver is loaded using static information in the registry. Take a look at the Toaster bus driver sample.

     -Brian


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

    Tuesday, September 9, 2014 5:05 PM
    Moderator

All replies

  • A bus driver for a virtual device creates the PDO usually in response to some external event, often a DeviceIoControl IRP, but it could be anything including creating the PDOs automatically when the bus driver is loaded using static information in the registry. Take a look at the Toaster bus driver sample.

     -Brian


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

    Tuesday, September 9, 2014 5:05 PM
    Moderator
  • or in the case of a root enumerated device, the kernel has a built in bus driver which creates the PDO

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

    Tuesday, September 9, 2014 6:27 PM
  • Hi Doron,

    Is the devcon.exe is used to create the root enumerated device ?

    Also is it possible to modify the inbuilt bus driver which creates the PDO ?


    lyf4sci

    Wednesday, September 10, 2014 5:23 AM
  • "devcon install" will create a root enumerate device. "devcon update" will install a driver on an already enumerated device.

    > Also is it possible to modify the inbuilt bus driver which creates the PDO ?

    I have no idea what you mean by modify. Can you please be specific?


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

    Wednesday, September 10, 2014 4:24 PM