Re: PROM variables

["Vincent Stehlé" <vincent.stehle@stepmind.com>]

Guido Guenther wrote:
[..]
> When doing this I'd write into the NVRAM
> directly instead of using the Arcs functions, I think the necessary info
> is in the IRIX headers.

I had a look at the ARC spec. (ARC/riscspec.pdf), and I am affraid the 
only (documented) way to access PROM env. variables are the two get/set 
functions.

In that case, the /proc approach makes sense IMHO.

Looking at hpc3 spec. and ip22-sc.c, I understand that PROM data are 
stored in the EEPROM behind the hpc3.

Maybe a reasonable approach is:

o write a new char device driver (as pc's /dev/nvram for example)
o move eeprom read/write routines from ip22-sc.c somewhere else,
   and use those routines both in ip22-sc.c and the char driver
o guess the format/offsets of the info. stored in nvram
o then write some user space app. to do the env. variable
   specific part.

In that latter case, the /proc approach makes less sense IMHO.

What do you think ? Am I missing some documentation ? Is there more in 
the IRIX headers ? (can't check right now, but I have them at home)

Regards,

--
  Vincent Stehlé