[coreboot] ASUS P2B Keyboard failure

Mark Marshall mark.marshall at csr.com
Mon Jan 18 15:52:47 CET 2010


I've been using coreboot and SeaBIOS with an ASUS P2B for some time now, 
and recently I've noticed that the keyboard has stopped working.

It took me some time to track down what was the problem, but running 
superiotool on the system after it had booted soon indicated the 
problem.  It appears that the keyboard sub-function of the winbond 
superio was not being enabled.  This is probably the reason that I 
didn't spot this problem sooner - it seems that if I boot with the 
factory BIOS and then chip-swap to coreboot and reboot things work as 

I've had a closer look at the Winbond data sheet and the initial value 
of this register seems to depend on an external PIO connected to the 
winbond chip.  I've also noted that in the coreboot source the 
pnp_enable function only disables functions - it doesn't enable them. 
Is there a good reason for this?

Should I submit a patch that always writes to the enable register, or 
should I add something to the superIO initialization that sets this 

Is my mainboard broken?

Any help greatly appreciated.


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