Subject: Re: bios stuff
To: None <M.Drochner@fz-juelich.de>
From: Christian E. Hopps <chopps@merit.edu>
List: tech-kern
Date: 02/03/2000 16:39:56
Matthias Drochner <M.Drochner@fz-juelich.de> writes:

> chopps@merit.edu said:
> > So while I was fixing my i386's pnpbios I noticed that we have a lot
> > of options and information available with pnpbios that we aren't
> > currnetly using. 
> 
> Yes. Using the ressource allocation data even if no pnpbios
> driver is attached would help a lot. But there is quite some
> work necessary to the bus_space stuff to allow other drivers
> to take over a ressource originally allocated to pnpbios.
> These are the limitations of the one-pass autoconfiguration.

I forsaw calling the firmware/bios through an API not using bus_space to 
manipulate it directly.

> > As 1 example we don't know all the different ways to disable and enable
> > Cardbus controller's pcic compat (i.e., legacy isa mode) and so
> > sometimes autconf just loses (finding both).  But through pnpbios you
> > can just say `disable this' and the bios DTRT.
> 
> Well, my testing base is a bit limited (consists of one Thinkpad
> only), but I've not yet seen a PnP node describing a pcic.
> Cardbus controllers shouldn't be handled by the PnP BIOS anyway
> because they are logically PCI devices.
> (What I've seen is that a PnP node exists for a soundblaster/wss
> compatible audio device which is physically implemented within
> a Neomagic PCI audio chip afaik. The legacy ressources shouldn't be
> described by the PCI device then.)

PNP0E03, PNP0E00 (io 3e0-3e1) at pnpbios0 index 10 ignored

Basically PNP0E03 is the cardbus controller and PNP0E00 is the pcic. My
understanding is that to disable the pcic mode you simply disable the
above pnp device node.

> 
> > So what I'm wondering is what is the proper way to take advantage of the
> > information and control ability presented to the kernel though the
> > bios/firmware in a nice and MI way?
> 
> Don't know... These mixes between clean buses as PCI and legacy
> devices are nasty, and I'm not very optimistic that it can be dealt
> with an an mi way.

Yes thats the problem obviously.  However my understanding is that there
are other issues that arise with ACPI that aren't handled by the `clean
busses' either (power management).

Chris.