windowsusbdriverwdm

How does PnP manager determine the appropriate function driver?

I am learing the loading process of Windows Driver.
But I cannot understand a part of the following article.

https://learn.microsoft.com/ja-jp/windows-hardware/drivers/install/step-3--the-driver-for-the-device-is-installed

In this article, there is the following description.

"4. The PnP manager loads the appropriate function driver and any optional filter drivers for the device."

I have a question about above description.
How does the PnP manager determine the appropriate function driver?

For example,
when a USB memory is plugged into a Windows PC then PnP manager will load disk.sys after loading a driver relating USB.
In this case, I want to know why PnP manager could judge that the device corresponds to disk.sys.
(seeing somewhere in registry? sending some requests to bus driver? and so on.. )

Solution

  • when bus driver detect and report PDO device PnP manager send several IRP_MJ_PNP to PDO device. including IRP_MN_QUERY_ID for get Device Identification Strings

    then formated registry key path in form 

    \REGISTRY\MACHINE\SYSTEM\CurrentControlSet\Enum\<BusQueryDeviceID>\<BusQueryInstanceID>

    in place <BusQueryDeviceID> string returned by device for BusQueryDeviceID and in place <BusQueryInstanceID> string returned by device for BusQueryInstanceID (Parameters.QueryId.IdType)

    this key opened or created. then was query for BusQueryHardwareIDs and BusQueryCompatibleIDs. result of this query saved in HardwareID and CompatibleIDs REG_MULTI_SZ values.

    and then PnP manager look for Service REG_SZ value under this key - if it already exist - the driver ( \REGISTRY\MACHINE\SYSTEM\CurrentControlSet\Services\<Service>) loaded and it AddDevice called with this PDO. if this value yet not set - was search via installed inf files in system - for best match HardwareID and CompatibleIDs. if found driver - result saved under Service REG_SZ value, for not search next time