Re: Is there a way to use Linux on the E450 ?

In article <450d56d2$0$4524$e4fe514c@xxxxxxxxxxxxxx>,
Casper H.S. *** <Casper.***@xxxxxxx> wrote:

Josh McKee <jtmckee@xxxxxxxx> writes:

I know what some of the features are. What I'm wondering is how often
these features are actually used/needed that would justify warranting
them over the simpler PC BIOS. Aside from the serial console I can't
imagine the other features being overly useful. For example how many
forth programs have you written and for what purpose? What do you mean
by "more configurable and flexible"?

One of the biggest BIOS issues is that it executes in 16 bit real mode; that
makes running a 32 bit OS somewhat challenging and makes calling after
boot not always possible (that why really only ACPI is used these
days)

This is more a limitation of the x86 processor than the BIOS. The x86
processor boots in real mode (16 bit). Since the BIOS is the first
software read on boot it has to be real mode compatible. OBP would have
this same limitation.

Furthermore this is not something that an end user is concerned about.

Likewise Suns 32 bit OBP systems couldn't boot a root partition larger
than 2GB. This limitation is similar to one of the characteristics,
booting within the first x cylinders, you consider brain dead for the PC
BIOS. Both platforms have long since removed this limitation.

It's a bug (generally caused by "we don't support this because we can't
test it; we could write the code now but then we probably need to
re-ship it because would probably be broken anyway)

Regardless it was a limitation imposed by the OBP just as the BIOS used
to impose a "boot from within the first x cylinders" limitation. Neither
are issues today.

Please note that I am not questioning the feature set of the OBP over
the PC BIOS. I'm just wondering how useful all those features are. The
systems that I've been exposed to are used to run applications within an
operating system. For these systems getting from power on to booting the
OS is about the extent of the OBP benefit. I would think that this
situation applies to the majority of systems.

Interesting features of OBP, to me, are:

- command line interface which allows you to interrupt
a running kernel and "do stuff", such as forcing a crash dump

Interesting but how practical?

- auto detect keyboard presence and switching to serial
console (really handy if you need to develop on a number of
systems and don't want them all in your office) KVMs switches
have various serious issues and BIOS "serial redirection" is
always broken in some way or another

A non-issue for PC servers equipped with LOM function.

- Forth would in principle allow devices delivered both bootable
on SPARC and other architectures (notably PowerPC which also
supports this)

Again interesting but how much has this been utilized in practice?

OpenBOOT is a standard specification and BIOS is not. Many BIOSes do
things slightly differently which makes it hard (but this could be
a consequence of there being so many more different PC motherboards)

Again: I'm not discounting the additional feature capability of OBP. I'm
just looking for examples of real world examples where people take
regular (there will always be someone who's digging into the heart of
any system) advantage of these features.

Josh
.

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