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[Steven Champeon <schampeo AT hesketh.com>]

on Tue, Dec 17, 2002 at 05:09:36PM -0600, Joe Reid wrote:
> If the OpenFrimware is anything like Sun's OpenBootProm, if "something 
> goes wrong" (TM) the diag-switch? environment variable will get set, and 
> then your normal boot sequence is changed.  printenv will print all the 
> openbootprom parameters on a sun, Steve or Steve can you comment on 
> Apple's Open Firmware?

Yup, same deal here. diag-switch? is set if there's a problem, and 
printenv works. You can do all sorts of voodoo if you know how to read
the OF dicts, or can spec a PCI path in OF by hand to specify the boot
image, etc. I never got that into it, frankly - just learned enough to
triple-boot my Pismo into Yellow Dog Linux, OSX beta, and OS 9. 

OF is a Sun/Apple project, FWIW, so it's no surprise that they're very
similar - they're supposed to be. Both are based on IEEE 1275-1994,
which in turn is based on Sun's OpenBoot 2.x.

 http://playground.sun.com/1275/

Don't miss the Open Firmware Song.

 http://playground.sun.com/1275/misc/ofwsong.au

The only commands I know from any Sun or Apple firmware implementation
(aside from how to set variables) are "probe-scsi", which I learned the
hard way, and "boot". I know you can use the forth interpreter to do
basic math, but it's been a while since I had a running Sparc around so
I could keep my chops sharp.

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