Drivers for small computers

This message may be a little off topic.

I have a virtual cd/dvd rom driver that works well on XP and Vista as specified.

Now I am asked to investigate writing a version for small computers, hand
helds, big phones etc.

I assume it is possible to add third party drivers to these devices. If it is
not please tell me now.

Initially I will be writing for Windows CE but it is hoped that the same can be
done for Symbian and other exotica that maybe out there.

I assume that the driver model I will be writing to will be substantially
different even for WindowsCE and that I may need to provide some class or even
file functions before it will work.

Can somebody suggest good resources for Windows CE (or Symbian) driver
development.

I am currently ignorant so most suggestions are helpful.