Windows System Software -- Consulting, Training, Development -- Unique Expertise, Guaranteed Results


Before Posting...

Please check out the Community Guidelines in the Announcements and Administration Category.

More Info on Driver Writing and Debugging

The free OSR Learning Library has more than 50 articles on a wide variety of topics about writing and debugging device drivers and Minifilters. From introductory level to advanced. All the articles have been recently reviewed and updated, and are written using the clear and definitive style you've come to expect from OSR over the years.

Check out The OSR Learning Library at:

2 FDOs on top of 1 PDO; writing a DVD-RAM driver

OSR_Community_UserOSR_Community_User Member Posts: 110,217

we have a NT 4 driver for DVD-RAM drives. This driver creates a CdRom and a
removeable disk device for each physical DVD-RAM device. This seems to be
necessary to mount either disk based file systems or CD/DVD-ROM file
systems, depending on the actual type of media in the drive.

Now in Win2K the world looks a bit different, so that I'd like to ask some
questions. These questions may not make sense in this order, but I am still
in the design phase.

1. Is it possible/allowed to layer two FDOs on top of port drivers PDO?

2. The legacy/NT4 version of the driver runs on Win2K, but I don't get any
mount requests for the disk device. Are legacy disk drivers just not
supported in Win2K or are we doing something wrong?

3. Does anyone outside of my driver know if a particular device object is a
FDO or a PDO? If no one really cares about it, I could add a cd/dvd type
"partition" beneath the disk partitions, allowing CD/UDFS to mount on the
cd/dvd device and the disk file systems mount on the disk partitions.

4. Is there a chance to install a storage device driver without any user
interaction? One way could be to copy my *.inf and the driver to inf\ and
drivers\, respectively and let Win2K install them when attaching the drive.
But the drive is usually already there when our software is installed,
that's why I need a way to do the "Change driver..." in my setup program.

5. Is there a way to tell pnp mgr in which order it should start the
devices? The problem is, that CDROM.SYS assumes that it is the only one who
creates \Device\CdRomX objects, so that he fails if someone already created
a device with the same number. Because the disk driver handles this
correctly, I guess Win2K SPn will fix this, but I afraid I can't wait.

If you have some answers, hints or want to tell me that I should do it a
total different way, please let me know.

Thanks and best regards,
Sign In or Register to comment.

Howdy, Stranger!

It looks like you're new here. Sign in or register to get started.

Upcoming OSR Seminars
OSR has suspended in-person seminars due to the Covid-19 outbreak. But, don't miss your training! Attend via the internet instead!
Kernel Debugging 13-17 May 2024 Live, Online
Developing Minifilters 1-5 Apr 2024 Live, Online
Internals & Software Drivers 11-15 Mar 2024 Live, Online
Writing WDF Drivers 20-24 May 2024 Live, Online