Hallo,

>> i figured i'd add a qfe card (a sun pci card that's a ppb with four hme
interfaces on it) and a dual gig ether (2 x wm) to my alpha, since i need
more interfaces.  sadly, neither of them works too well.
>
> Most alpha's don't like pci-bridges,
> dual/quad eepro100 cards always caused
> funky srm behaviour with my 164sx.

a while ago, i fixed up some of this bridge stuff for AlphaStation 200 and
PC164 for, ermm, FreeBSD :) It was a bit fiddling, but finally, it was no
problem to get this quad StarFire running there.

One of the most important issues... behind a bridge, you don't want to use I/O
space mappings. There are some knobs to play around, but finally you just have
to make sure, your adapter is memory mapped. I/O mapping (which in fact
doesn't really exist on Alpha) works only on the primary bus without evil
problems, because bridges must have assigned a further I/O range to provide
this range (in parts) to the devices behind the bridge. On top sits the fact,
that SRM doesn't assign I/O resources to bridges or at least devices behind
them. So, if your kernel uses I/O resources, it uses the unconfigured bogus
values and might crash. The last issue was interrupt routing, this was quite
evil on AlphaStation 200 in some way. But i have to grab out my patches to
find out the details again. Or you have a look at the FreeBSD-alpha PR
database.

...Michael

-- 
http://www.unixiron.org/    Home Powered by: (Net|Open|Free)BSD IRIX
NonStop-UX Solaris AIX HP-UX Tru64 MUNIX Ultrix VMS SINIX Dolphin_Unix
OpenStep MacOS A/UX