How to write a WDM driver as a service?

Hi:

I’m trying to write a win32 service which runs on windows 2000/xp.I found that if I wrote a WDM style driver instead of a NT style one,the driver could not start at all.

Then I traced the progress and found that the AddDevice routine was not called and no Pnp Irp was send to the driver.

While I write a NT style driver,everything seems to be fine.But if I write a NT style driver,I don’t know how to get the PDO which i must get to make my program work.

Can anyone give me some idea about how to write a WDM style driver as the service?

Thanks in advance.