So, thanks to the great feedback I've gotten so far, I've been able to 
get my driver to attach in a way that at least resembles working, so now 
I'm on to some different problems. For those just joining the 
conversation, the board in question is an interface to the PSTN to 
support asterisk, a

I'm noticing some timeouts on my ethernet card when booting with the new 
kernel, so I suspect I may have mis-chosen the interrupt level, or 
perhaps I'm doing something wrong in the interrupt handler.   My cursory 
reading of the literature leads me to believe that FreeBSD 5.2's 
interrupt levels (the freebsd driver sets INTR_TYPE_MISC) don't 
correspond directly to NetBSD's, so I somewhat arbitrarily chose 
IPL_BIO, knowing that in all likelihood I'd need to change it.  However, 
I can't seem to find a decent guide, so I'm nearly as much in the dark 
as before.  My next guess would be perhaps IPL_AUDIO, but I probably 
shouldn't be stabbing around blindly here.  Is there a concise 
definition of what levels block what somewhere in the source? 

Also, there's one other (obvious) wart in the code right now - the 
FreeBSD code uses vtophys() to get the DMA address to write to the 
card... I suspect this will _work_, since I'm using an i386 here, but 
from what I can glean from the source, it's not allowed for MI code - so 
what's the bus_space (or is it bus_dma?) equivalent?

Thanks again for all the help to this point - I've gotten the 'dummy' 
driver working thanks to the suggestion to examine dmover_io.c, and the 
hardware attachment "working" by loading "zaptel" as a 
non-pseudo-device... and I hope to have it actually passing calls with 
just a little more work.  Then I can start the code cleanup.  :-)

+j

-- 
Jeff Rizzo                                         riz@redcrowgroup.com
Red Crow Group LLC                                 http://www.redcrowgroup.com/
+1 415 550 0310