[Openec] Few questions about KB3700/3926

Frieder Ferlemann frieder.ferlemann at web.de
Wed Jul 23 16:16:19 EDT 2008

Hi Maxim,

Maxim Levitsky schrieb:
> I got dump of all of them, and I did the dump several times and got 
> exactly the same result
> (I first wait for XBISEG to be non-correct value, then wait for it to be 
> correct value, so I am at beginning of window, and I repeat this process 
> 4 times until I got same results all 4 times.

Nice that this worked out fine. Maybe a word of warning (which obviously
was not needed and does come too late anyway)
On the XO (the versions where this still is allowed) the main CPU
could issue requests so quickly that the SPI memory was completely busy.
And the 8051 thus could not fetch instructions any more which
is potentially dangerous...

> Btw, I probably will extract EC firmware from bios now since I know its 
> contents I can just search in bios range (last few megabytes of 4GB range).

Yes. If you know what to look for take it from the original:)

> PS:
> I have seen on your website that you still can't power the XO.

Yes, that unfortunately still is the status:(

I myself seem to be looking at the wrong schematic, wrong datasheets,
missing something info, am being stupid, whatever.
Maybe the XO was even powered once and I just didn't notice because
the main CPU was waiting for something that the EC did not yet do.
(yes I'm clever enough to admit that this falls under stupid as well:)

After realizing that I did not succeed on my own I tried to lower
the hurdle (from C programming to using a monitor program via
serial terminal) but nobody picked up the task.

For somebody familiar with AMD development boards it might be a small step.

> Can you disassemble the EC firmware for that? Or there are legal problems?

I do not want to because I fear that this would endanger the vision
of getting unencumbered GPL'ed firmware for the EC.
Information like "put pin X from tristate to push/pull
and set hi/low for at least xx ms, then wait for acknowledge on pin Y
to be valid, in this case switch pin X to pull-up or input
and proceed with setting Z to ..." would probably be legal
to use.
But likely not legal to use if I gained this information
by disassembling the first 64k of XOs firmware (IANAL).

The most recent publically available information about OpenEC that I'm
aware of is within these threads:


More information about the Openec mailing list