> is there something like a "HOWTO write a device driver
> for NetBSD"? I've got McKusick's "The Design and Implementation
> of the 4.4 BSD Operating System". Are the parts on device
> driver (attachment etc) and interrupts applicable for
> NetBSD?

I'm currently writing one.  As a start, read:

McKusick, et. al.  pp496--502 (autoconfig)
	c.f.,	/sys/kern/subr_autoconf.c
		/usr/include/sys/device.h
		/usr/include/sys/conf.h
		/sys/arch/{some_arch}/compile/{some_dir}/ioconf.c

McKusick, et. al.  pp195--204 (device driver overview)

http://www.netbsd.org/Documentation/kernel/programming.html

For info on the "top half" of the device driver, it may be instructive to look 
at /sys/miscfs/specfs/spec_vnops.c and a sample driver like /sys/dev/ic/com.c 
and /sys/dev/isa/com_isa.c or something platform specific like 
/sys/arch/i386/i386/apm.c.

...or hang tight for a couple of weeks until I can get a tutorial written and 
proofed.  There are quite a few details that can only be learned by reading 
code at this point.

Another excellent reference (especially on specfs) is Unix Internals: The New 
Frontiers, Uresh Vahalia, Pren. Hall, 0-13-101908-2.


-- 
Bill Squier (groo@cs.stevens-tech.edu)
http://www.cs.stevens-tech.edu/~groo
Ph: (201)216-5486   Fax: (201)216-8249