> If you read the MAKEDEV script, you find that it's mostly doing mknod.
> The man page for mknod says to look here for more info about major
> numbers:
>
> ``/usr/src/sys/arch/<arch>/<arch>/conf.c''
>
> But I just looked at a few architectures and conf.c doesn't exist.

it does on my 1.6.1 system.

/usr/src/sys/arch/cobalt/cobalt/conf.c

> But if you figure it out it would be nice to get smb devices built
> too. I got the kernel to compile with SMBFS, but MAKEDEV doesn't build
> the devices.

there are currently no major numbers for audio or for smbfs (the 
major.i386 file references nsmb).

compare:
http://cvsweb.netbsd.org/bsdweb.cgi/src/sys/arch/cobalt/conf/majors.cobalt

with:
http://cvsweb.netbsd.org/bsdweb.cgi/src/sys/arch/i386/conf/majors.i386

i'm not sure what the process for obtaining a major number is.  but i
don't think it is as simple as getting one assigned and then the device
magically working.  someone else will have to field that one.