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Re: Call for info: slave drives bootable from OpenFirmware (OldWorl d)



On  16 Apr, this message from Ethan Benson echoed through cyberspace:
>> Yes, sorry for not being clear, I did mean the first _bootable_
>> partition.
> 
> hmm, can more then on partition be marked bootable on mac tables?

No idea. Paulus should know that...

> i am not sure how to unmark a partition as bootable. 

dito.

>> Here you are. Top part is what's in there after an Cmd-Opt-P-R:
> 
> you mean there is something in nvramrc by default?  or does
> Cmd-Opt-P-R not reset nvramrc? 

Absolutely. Don't ask me why they didn't just _fix_ the ROM proper,
instead of burning a buggy ROM containg patches to these bugs...


[default nvramrc snipped] 
> do you know what this code does?  i don't speak forth very well.  

No idea. I didn't try and see whether it boots without it ;-)

>> The problem I see is more in finding out what's already in the nvramrc,
>> possibly differing Apple-supplied patches, and various user-supplied
>> patches. Cooking this all together to get something sensible might be
>> non-trivial.
> 
> yes it would be non-trivial.  i think the only sensible way to do it
> would be to come up with a specific nvramrc patch for a given machine
> and install that replacing anything already there (with permission and
> after saving the current contents of course).  

Do me (especially me with my need for G3 hackery) a favour and include
the possibility to add user-supplied nvramrc patches. Editing a saved
copy and reapplying that is probably ok.

> something else that would be useful is building a custom boot floppy
> that is loaded by the hardware MacOSROM which does nothing but restore
> a nvram configuration, for the case where a linux only box gets its
> nvram zapped it can be made bootable again without much pain or
> trouble.  this is even more non-trivial though, and beyond my
> abilities... 

That would be useful in some extreme cases; but how about saving a copy
in a format understood by bootvars, the MacOS app? It's a first start in
this direction; from there on building a bootable floppy with bootvars
(maybe modified) runing as Finder should'nt be too much trouble. Plus,
that saved copy can simply be copied to a MacOS install (if available)
for restarting. Plus, anybody using both Linux and MacOS on the same
Oldworld machine will have a regular need for this file ;-)

> the trick i think is writing a distributable nvramrc patch for each
> machine, then identifying the machine and installing the correct
> patches.  

There may be danger in doing this; we should first be _very_ sure what
nvramrc contains by default on each box. I couzld very well imagine that
there are different revisions of the same box with revised nvramrc
patches... without incrementing the OF version number. Probably a
positive list of known machines is a minimum; but still potentially
dangerous...

Cheers

Michel

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