[OpenBIOS] Re: [fb-d] next problem: keyboard.

Jeff Garzik jgarzik at mandrakesoft.com
Thu May 4 20:44:27 CEST 2000

Ronald G Minnich wrote:
> On Thu, 4 May 2000, Jeff Garzik wrote:
> > Ronald G Minnich wrote:
> > What are the symptoms of the failure?  Does the Linux kernel print out
> > any keyboard-related messages?   Does booting even get far?
> The kernel is up with a login prompt, displaying very nicely on the Matrox
> (cool logo in the upper left, BTW). When it tries to do anything with the
> keyboard, however, nothing happens.
> Turns out that you have to do a bit of work with the PIIX4E power
> management registers to get things like keyboard going. I'm still digging.
> docs: SiS not on the web yet. They will be happy to send docs, however,
> those guys are really cool. For Intel, I will try to remember the links,
> but at the least you need the PIIX4E manual.

I've got the PIIX4* manuals, so all I would need is the
southbridge/northbridge databooks.  Those are the ones which IMHO may be
more important to getting keyboard going than the PIIX4 manual...

Comments from the PIIX4 manual:

* The PM registers relating to keyboard are probably red herrings -- it
appears you are only signalling that keyboard events should generate PM
event interrupts, which isn't what you are looking for
* The Fast A20 bit (bit 1 of port 92 register) is logically combined
with the input from the keyboard controller. (x-bus interface, a20gate
signal)  maybe that is significant, maybe not.
* have you enabled X-BUS accesses (function 0, register XBCS 0x4E-4F)
* have you enabled the keyboard interrupt?
* have you cleared the kbd interrupts (RIRQ, 0x60)
* is the USB keyboard interface "stealing" the keyboard port for
itself?  (register C0-C1)
* port 92 (P92) register mentions keyboard
* possibly important bits:  keyboard bit on DEVRESA register (function
3, bit 28, register offset 0x5C-5F) and DEVRESB register (function 3,
bit 30, register offset 0x60-63)

Jeff Garzik              | Nothing cures insomnia like the
Building 1024            | realization that it's time to get up.
MandrakeSoft, Inc.       |        -- random fortune
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