kernel environment between reboots, diskless

[Steve Watt]

Greetings,

I'm working on a dataless system that will be booting and rooting
from flash for some environmental chamber (thermal) tests, and
logging the results to an NFS server outside the chamber.

The problem is that the driver for the card under test only supports
one card at a time.  That's relatively easy to hack around by passing
in a kernel environment varible from loader that indicates which PCI
slot is OK.  Then the probe routine of the driver looks for that
variable and won't accept the device unless it matches.

I'm trying to see if there's a way to get that information into the
loader (or the driver) in some way that doesn't require rewriting a file
in the flash every reboot, to avoid flash write cycles.

I know there's some amount of NVRAM in PCs, but didn't spot anything
about how to get at it from the driver.  It'd be nice, for this
sort of application, if there was a way to stash somewhere between
2 and 8 bytes somewhere...

Thanks for insights!

Pls cc: me directly on replies.

-- 
Steve Watt KD6GGD  PP-ASEL-IA          ICBM: 121W 56' 57.8" / 37N 20' 14.9"
 Internet: steve @ Watt.COM                         Whois: SW32
   Free time?  There's no such thing.  It just comes in varying prices...