Geode GX1 processor?

[Ferenc Engard]

Sorry for being late, my router / mail server has hardware problems. :-(

> > A bit offtopic: I am looking for a forum/mailing list/people who are work
> > with this processor, especially with its 2d video accel on linux. I have
> > problems, NSC didn't respond, and I stucked... :-(
>
> you can split a list off for geode, but we're interested here, and I would
> welcome a discussion on this list -- it's not a high traffic list.

I know, it's a refreshment after lkml, or, say, comp.lang.tcl. :-)

So, my problem is not related to linuxbios (maybe there will be one time,
if we decide to use this processor for our product).

I have an Advantech PCM-5820 board, with GX1 and CS5530, and I play with
it to test it's hardware bitblt feature. I have patched the 2.4.17 kernel
with NSC's geodefb driver, compiled a user-space GAL lib. I wrote a
program to move a part of the screen, the usleep a short interval (aka
scrolling a region). I know that this is not nice as the GX1 spec said
that I should not use the fb while the bitblt engine is working, and
because I have fb console, the console writes into it (it do not know
about the bitblt engine), but there was no problem, the center of the
screen scrolled like a dream, just when I typed something, there were 1-1
pixel errors.

The problem was when I decided to check the memory bandwidth, and issued a
dd if=/dev/mem of=/dev/null bs=1024 count=16384
command. Sometimes (about every 2nd time) it completely freezes the
machine. No oops, no kernel panic, just freeze to death. :-(  And I do not
understand what is going on, because if I do not scroll, there is no such
problem, and the bitblt operation just means to write some values into
some (processor-handled) IO registers.

What could be the problem? How to debug? What 'dd if=/dev/mem ...' exactly
do? Many questions, and I have not answers. What a philosophical work is
ours... :-)

Thanks:
Circum