Subject: Re: start linux - openfirmware?
From: Juan Manuel Palacios (jmpalacios@mac.com)
Date: Sun Jan 06 2002 - 08:22:16 MST
Well, I have to start by being honest here: I am not at all THAT
familiar with OF, I just learn about what I play with. Even though it
might sound a bit dangerous I've digged into it by myself and learned
with time and by being cautious. Please, always be at OF or you could
render your computer unusable. Anyhow I think I can give you at least
the starters of an answer to your question. OF works in at least close
to ensemble code if not so. It identifies hardware attached to the
mother board by specifying paths to them that contain things like
prefixes: the specify if wether the device is on SCSI or IDE controllers
directly attached to the mother board, or on PCI or AGP bridges that
lead to tspecific cards. In this last case the prefix has to indicate
the type and number of slot with its hardware address. Later you would
see some text that could contain slashes, colons and hexadecimal
numbers, among many other things. These could stand for hardware memory
addresses or bridge to PCI or AGP ports, as I previously said. These
things are mainly bus addresses so that the mother board can find its
way to the device. Lastly you could see suffixes just as with the start
up device: the termination "tbxi" indicates OF that the computer can
actually boot off of the specified device. If it were not appended boot
up would fail instantly.
And on the other hand are the OF commands. Well, those are just
very particular, sintax sensitive and ABUNDANT!! If you want to have
some fun type at the OF prompt "words", and separate time in your day to
just read through the long list of OF commands that will be printed to
your screen. If I recall correctly you can get some tips and help by
typing "help 'word'", where 'word' stands for the command you want to
know about. Try this out and tell me where it takes you, I'll be digging
into it here to see what I find.
I think that's something to get you started. Maybe there is some
programmer or hardware engineer on this list that will probably slap me
because of thinking that what I just said here is pure bull^$*@#! Sorry,
I'm just trying to make out what I understand out of all this.
Sincerely,...
Juan.
On Saturday, January 5, 2002, at 08:39 PM, Riccardo Gusso wrote:
> I have always been curious about this: could you explain me how it
> works?
> Thanks in advance.
>
> Rick
>
>
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