Re: FW: HOT Plug and Expansion ROMs

["Monish Shah" <monish@hpfcmss.fc.hp.com>]

I (Monish Shah) originally wrote:

> >Counting on the expansion ROM to do your initialization has another
> >problem.  May be the expansion ROM won't be run at all.  In PC compatible
> >systems, this can happen if you run out of space for BIOS.  The BIOS code
> >must be copied to memory below 1M, so there is a limit to how many BIOSes
> >can be executed.
> >
> >So, it is best to have your device driver do full initialization both
> >because of hot plug and because of BIOS space limitations.
> >
> >I realize that Openboot firmware (which you described as F-code) is a
> >solution to both problems.  However, I suspect that having drivers do full
> >initialization is the path of least resistance for PC compatible systems.

Greg Hill replied:

> You are probably right in your last statement.  But PCI is not restricted to
> BIOS-based systems.  There are PCI-based systems out there using Open
> Firmware/FCode and the elimination of FCode from the cards used in such
> systems *is* a retrograde step.  IMHO, Tony is absolutely correct in his
> presentation of the facts.  FirmWorks supports Tony's suggestion that FCode
> ROM images not be forbidden.  If the BIOS world wants to take "the path of
> least resistance", that's up to them.  Please do not handcuff those of us
> who are using a different approach.

I don't see how I was "handcuffing" anyone.  The original mail in this
thread was proposing to *require* all systems supporting hot plug to
support FCode.  That would certainly handcuff the BIOS world.  I was
pushing back on that.

If somebody wants to build a Hot plug system that supports FCode and runs
FCode on a hot plug event, I don't have a problem with that.  Drivers
intended specifically for those types of systems could choose not to
perform complete initialization.  However, I don't believe this will make
sense for PC compatible systems.

Monish Shah
Hewlett Packard
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