Writing a DX1 device driver for Vista

I recently upgraded to Vista after an incident involving a replacement video card resulting in a lost hard drive (don’t ask), for the most part I actually prefer Vista to XP. About the only real downside (other than the stupid security escalation dialogs) was the lack of a driver for my Ergodex DX1.

After rummaging through the Ergodex forums and waiting for them to actually provide a driver, I ran across this site http://ergodex.hydraproductions.com/wiki/ since Dom had already reverse engineered the USB protocol I thought I’d try writing a driver for the device.

I think the last time I wrote a device driver of any description for windows might have been circa windows 3.1. I have a pretty good understanding of the hardware and the underlying protocols, because Consoles usually don’t make much of an effort to hide the nuts and bolts, but my Windows skillz leave a bit to be desired.

I downloaded the windows DDK, scanned the examples, and started messing around with the Bulk USB sample. After a while it became obvious I was going to have to install another copy of Vista on a second box in order to debug anything or at least use my laptop as the target. I was scanning through the docs and I came across the WDF doc, it seemed that the UMDF provided everything I needed to write a USB driver in usermode and allowed me to debug just by attaching Visual Studio to the running device process.

So on Sunday night I started experimenting with one of the samples, by Wednesday Night the driver was basically functional. It’s changed a bit since then because I changed my mind on how to communicate with the programming/macro playback software. Since then I’ve put together enough of a programming/macro app to do what I need.

There are two things that jump out at me from this experience,

The first is how well designed at least the UMDF portion of the WDF is, the reason I could write a driver in literally 3 or 4 evenings, was that the base functionality just does the right thing most of the time just leaving you to marshal data and pass it on.

The second, is how frustrating it is that a company like Ergodex still can’t get Vista drivers out, the vast majority of the work for the suit is in the programming tool and I’m sure the XP one Ergodex has could just be dropped on Vista, just leaving the part that took me 3 or 4 days.

I’ll release the driver here along with my horrible programming application when I get some time to make a pass on the code. I’ll also release the source code for none commercial purposes.