[9fans] Whither nvram?

[Dan Cross <cross@math.psu.edu>]

I was setting up a CPU/auth server on a recycled VALinux server the
other day (hooray!) and ran into an annoying problem with reading
nvram contents.  Basically, this particular server had disk bays
that took SCA SCSI drives, and there was literally no way to have
an sd00; the smallest SCSI ID one could use was sd01.  So, readnvram()
/sys/src/libauthsrv/readnvram.c never found my nvram sector.  That
was highly annoying, and I fixed it by adding the appropriate lines
to nvtab to look at sd01 in addition to sd00 and sdC0.  Still, that
seemed kind of ugly and it struck me that it would be a better
solution for readnvram() to honor an ``nvr'' environment variable
if such a thing existed.  That way, the location of the nvram parition
could be set in plan9.ini.  Does that seem like a reasonable change
to other people?  If not, it'd be nice to see the sd01 entries go into
nvtab.

	- Dan C.