[Fwd: Re: [syslinux] etherboot 5.3.14 and pxelinux keyboard problem]

[Michael Brown]

On Wed, 16 Mar 2005, H. Peter Anvin wrote:
> Quinn wrote:
> >  I did some more testing with the code and have narrowed 
> > the problem down.  Up until pxelinux.0-2.08-pre6 - the keyboard is 
> > responsive when booted via etherboot.  pxelinux.0-2.08-pre7 and up start 
> > having the keyboard lockup problem.
> > 
> > Here is a diff file of the changes between pxelinux.0-2.08-pre6 and 
> > pxelinux.0-2.08-pre7: 
> 
> Okay, this is weird.  There is nothing in this code *at all* that would 
> cause this kind of problems.  Michael, does Etherboot muck with the
> 18.2 Hz BIOS timer interrupt at all?

Not in this situation.  Etherboot only hooks an IRQ when it's using its
UNDI driver to use an underlying PXE stack; if the PXE stack reports that
the NIC's IRQ is 0 then Etherboot will end up hooking the IRQ0 vector.  
However, in this situation, the UNDI driver is not being used (it's the
3c90x driver, IIRC), so Etherboot won't be doing anything to the interrupt
vector table.

It may be worth getting check_for_arp to print out the values of 
BIOS_timer and IdleTimer each time it is called.

Michael