Well, a reasonably skilled programmer can figure out how to write a basic
device driver pretty quickly. I found (having done both) that writing a
driver in Linux is a lot easier to figure out without documentation then
writing a (kernel mode) driver for Windows NT *with* documentation.
And anyhow, there are more books on driver-writing for Linux then there
are for Windows NT.
However, when someone like myself is pushing the envelope, trying to get
the most performance out of my board (which is why I use Linux in the first
place) I feel the need for a little extra help. For example, I have hardware
that drives 2-page/second gray scanners and I want to find out about all the
neato tricks for speeding the delivery of this data to a user-mode process.
How do I get access to user-mode memory? Can I DMA directly to the buffer
passed to the read call? Can I invalidate a page that has been mmapped from
my driver?
What would be really helpful is a small man page for every function within
the kernel, and a few mino-howtos for some common driver writer tricks.
DDI man pages.
-- Steve Williams steve@icarus.com steve@picturel.com"The woods are lovely, dark and deep. But I have promises to keep, And lines to code before I sleep, And lines to code before I sleep."