问题
Take a look at this example: a USB device in Windows 7 is reported to have Device instance path(DevinstPath) USB\VID_1EAB&PID_0501\7&25C389C1&0&1 and I know exactly that it corresponds to the so-called hardware-key(hwkey) in registry.
Now my question is: When my KMDF driver code has WDFDEVICE handle for that USB device, how can I know its DevinstPath?
I know I can
- send a BusQueryDeviceID to achieve the so-called device-id USB\VID_1EAB&PID_0501;
- send a BusQueryInstanceID to achieve the so-called instance-id 1 .
But I don't know how to get the so-called "instance-path". Could some kernel guru kindly tell me how I can get that?
MSDN doc seems really vague on this!
BTW: I also realize that user-layer function SetupDiGetDeviceInstanceId actually returns the DevinstPath -- although it is named "InstanceId".
回答1:
Device instance path can be queried using DEVPKEY_Device_InstanceId, using either WdfDeviceAllocAndQueryPropertyEx or IoGetDevicePropertyData (passing the WDM physical device object)
回答2:
Device Instance id is autoincrement sequence.
You can find HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum in registry;
Rules:NextPareneID.XXXXXXXX.N
XXXXXX use UUID Calculation crc32 values(test ok)
N is 1~9
Device Instance id format is N&PareneID&random's number&index
enter image description here
来源：https://stackoverflow.com/questions/44776328/how-to-get-device-instance-path-from-windows-kernel-driver