[WeakSauceIII]

Can someone please post complete instructions on how to write a driver from scratch?

kidding...

I have done some development in windows on this topic and am researching the BSD way. I have the book "the design and implementation of the FreeBSD operating system" and it has a lot of good detailed info on the hardware setup and seems to be mostly relatable to OpenBSD. I also have the book "Writing Unix device drivers" by george pajari. It's dated (around 1991) and specific to UNIX system V but gives detailed walkthroughs and source code for all drivers types explaining the code line by line. It also seems to be at least 70% relatable to BSD. The combination of these two gets me real close. My question is this, where can i get the hardware specs for a device? I mean the low level control registers and such. I know that most of that is proprietary and not available which is what makes it hard to make OBSD compatible drivers but for the hardware that is open does anyone know a good site or resource? I'm not even sure what to call it. I searched for technical specs, driver specs ect... on intel and other sites but i can't find what I'm looking for. Of course the source code for OBSD drivers is a great resource as well.