[LinuxBIOS] Support for VIA K8T890/VT8237

Rudolf Marek r.marek at assembler.cz
Sun Mar 25 12:42:20 CEST 2007

Hi all,

Ok I subscribed ;)

> For now, you should be fine without the K8T890 datasheet, as it's *just*
> the PCI-Express controller.

It has a V-Link registers too. (To support communication with VT8237). This
seems to be compatible with CN400. I dont figured out yet what are the PCIe regs.

> Your first problem will be supporting the
> via 8237 southbridge, which, if you have all those docs, should be
> fairly easy. 

Stephan wrote on IRC he might have time to do that too. I will keep with him in
touch. (As for the docs ... hfr gur uvagf). I think I will start with it after
10th of April.

> After that, you'll have to work out DRAM initialization,
> which is done by the K8 (already supported in linuxbios). Once you've
> done all that, PCI-Express will be your next step, but I don't know much
> about that (I don't own any PCI-E stuff yet).

Yep. Sounds as reasonable plan. I have seen in archive people asking for the
kickstart stuff. I would like to ask too ;) I need to know how to fill in proper
way the "root complex" structure for my board. Is there such information
somewhere? Thanks.

> I'm amazed that noone has gone and gotten vt8237 up and running yet, as
> it seems that it's used on a lot of motherboards these days, from the
> latest via epia-m's to cheaper C7, K7 and K8 boards.

Just for the record, there are at least 3 PCI ids for the VT8237, so we might
support all of them. I think just  (I know because of i2c support for lm-sensors).

And my last question, do you support (infrastucture) the clockchips and custom
FSB/HTT/mem ratios? I have a bit overclocked system (255 instead of 200 freq -
all other divisors set up to match original freq). I dont need to change
voltages, so I think I need only to change the HTT link divisors, mem divisors
and ClockChip at 0x69)


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