[LinuxBIOS] 440BX progress.

[Uwe Hermann]

On Sun, Nov 26, 2006 at 07:02:51PM +0100, Segher Boessenkool wrote:
> >Is that the canonical way to test whether RAM init works?
> 
> The "canonical" way is to attach a memory bus analyser to
> your board.  Failing that, you can run some stress tests
> (like, boot Linux and do some disk+network load on it, or
> similar).  If everything works, your memory works, eh?  :-)

Sure, if I could boot Linux or memtest my problems would be solved. But
currently I haven't yet managed to do so. The problem now is, that I
don't know whether booting memtest fails because I need to setup more
of the mainboard-specific stuff or because my RAM init doesn't work yet.


> >What's the absolute minimum config I need to get _something_ to boot, 
> >so
> >that I can verify that RAM init works?
> 
> You can dump out the PCI config space of the memory controller
> after its init -- so you can check if that looks good (against
> the data sheet).

I think it does, I specifically hard-coded the values so that they match
the output I got from a running Linux using the factory BIOS (and as far
as I can see that's fine compared with what the datasheet says, too).

lspci -xxx 0:0.0 on Linux system:
00: 86 80 90 71 06 00 10 22 02 00 00 06 00 40 00 00
10: 08 00 00 d8 00 00 00 00 00 00 00 00 00 00 00 00
20: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
30: 00 00 00 00 a0 00 00 00 00 00 00 00 00 00 00 00
40: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
50: 0c 8a 00 ff 00 00 00 09 00 10 11 01 00 00 00 00
60: 00 00 00 00 00 00 08 08 00 00 00 00 00 2a 00 00
70: 20 1f 0a 38 00 10 10 01 23 ff 10 38 00 00 00 00
80: 02 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
90: 98 cc 00 00 04 61 00 00 00 05 00 00 00 00 00 00
a0: 02 00 10 00 03 02 00 1f 00 00 00 00 00 00 00 00
b0: 80 20 00 00 30 00 00 00 00 00 9f 03 20 10 00 00
c0: 00 00 00 00 ff ff ff ff 18 0c ff ff 61 00 00 00
d0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
e0: 4c ad ff bb 8a 3e 00 80 2c d3 f7 cf 9d 3e 00 00
f0: 40 01 00 00 00 f8 00 60 20 0f 00 00 00 00 00 00

Northbridge dump from LB via serial:
00: 86 80 90 71 06 00 10 22 02 00 00 06 00 40 00 00
10: 08 00 00 d0 00 00 00 00 00 00 00 00 00 00 00 00
20: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
30: 00 00 00 00 a0 00 00 00 00 00 00 00 00 00 00 00
40: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
50: 0c 8a 00 ff 00 00 00 09 00 10 11 01 00 00 00 00
60: 00 00 00 00 00 00 08 08 00 00 00 00 00 2a 00 00
70: 20 1f 0a 38 00 10 10 01 23 ff 10 38 00 00 00 00
80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
90: 80 00 00 00 04 61 00 00 00 05 00 00 00 00 00 00
a0: 02 00 10 00 03 02 00 1f 00 00 00 00 00 00 00 00
b0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
c0: 00 00 00 00 ff ff ff ff 18 0c 00 00 00 00 00 00
d0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
f0: 00 00 00 00 00 f8 00 00 20 0f 00 00 00 00 00 00

There _are_ differences, but nothing related to the RAM config registers
as far as I can see.


Uwe.
-- 
http://www.hermann-uwe.de  | http://www.holsham-traders.de
http://www.crazy-hacks.org | http://www.unmaintained-free-software.org
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