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

[Quinn]

H. Peter Anvin wrote:

> Quinn wrote:
>
>> H. Peter Anvin wrote:
>>
>>> Quinn wrote:
>>>
>>>> Hello again,
>>>>
>>>> Back to an old case:  Etherboot 5.3.14 and pxelinux.0
>>>> I just tested v3.11 of pxelinux.0 - same problem as described below 
>>>> - keyboard hangs at boot prompt.
>>>> I also tested v3.10-pre21 - someone mention that arp polling was 
>>>> disabled for this version.
>>>
>>>
>>>
>>>
>>> What about current Etherboot?
>>>
>>>     -hpa
>>>
>> Same results with etherboot 5.4.1/pxelinux 3.11 and etherboot 
>> 5.4.1/pxelinux 3.10-pre21.
>> pxelinux 3.10 gives the same results as pxelinux-3.10-pre21.
>>
>> When the keyboard hangs, Num Lock/Caps Lock/Scroll Lock work fine but 
>> typing anything in
>> does not show up at the boot prompt and if you keep on trying then 
>> the keyboard buffer
>> overflows (beeping noises).  Pressing the enter doesn't do anything 
>> either.
>> Rebooting the pc with CTRL-ALT-DEL works fine though.
>>
>
> I suspect Etherboot has nothing to do with it, but it might be an 
> issue with your BIOS and the INT 16h AH=1xh functions.  Since this is 
> one very old machine I don't really think I'll have the time or energy 
> to chase this one down, unless reproduced on other hardware.
>
>     -hpa
>
As I know you like to know the exact point the problem occurs, I did 
some playing around and found the breakpoint between v 2.08-pre6 and 
2.08-pre7. All versions beginning with 2.08-pre6 and below works with 
the keyboard.  2.08-pre7 and up, the keyboard locks up.

I then did a diff and applied the diff to 3.11.  This fixed the 
keyboard, but trying to load an image hanged the machine.  Ethereal 
capturing showed that tftp and pxelinux were working together.  Ethereal 
showed that pxelinux.0, the default config file, and memdisk loaded - 
but then abruptly stopped there.  pxelinux did get all the packets for 
memdisk, but it did not attempt to load the initrd file through tftp.  
The last message on the console was "Loading ".

Checked a bit further...  The "Loading " hangup seems to be caused by 
parsing of the command line procedure in runkernel.inc.  The hang seems 
to be introduced between 3.02-pre4 and 3.05.  I couldn't pinpoint the 
exact instructions for that problem.

The last hang that I haven't checked into yet is, fx you type "memtest" 
at the boot prompt.  pxelinux then shows "Loading memtest.." and then hangs.
Again, the hang points to runkernel.inc just after the procedure for 
parsing the command line.  I haven't found out yet exactly which version 
of pxelinux has introduced this bug.

It looks like runkernel.inc is also being used in syslinux/isolinux.  
I've tested syslinux/isolinux 3.11 on the same 486 machine and it works 
perfectly so I am not sure why there are so many hangups with the 
pxelinux code.

Does this information give you any help at all to what is happening in 
the pxelinux code on a 486 machine?

Quinn