Li-Ta Lo ollie at lanl.gov
Sun Jul 24 19:05:20 CEST 2005

On Sun, 2005-07-24 at 23:52 +0900, Jun OKAJIMA wrote:
> >> 
> >> I think that one solution is hard coding the params of mem
> >> in a BIOS image. But, how?
> >> 
> >
> >The documentation from VIA is simply crap. Nobody actually really
> >know the correct value to program to the memory controller. 
> >
> >
> Sorry, My explanation was wrong. I tested many combination 
> of M/B and DIMMs. And found most of then dont work at all, but
> a little of them work rarelly. I mean, some combination work
> but VERY unstable. For example, work once in 100 times reset.
> So, My idea is, for this kind of very unstable combination, do like this.
> 1. add a func outputting params to console.
> 2. try, try, try. push reset, push reset and hope to run.
> 3. If it works as it happens, hard code this param to the src.
> 4. hope runs stably.
> How about this way?

You can try it but the current implementation in the SVN tree is 
probably the best thing we can get.

The chipset is really a headache, even adding some console output in
the DRAM init phase will crash the system.

If you do have a lot of time and MB/DIMM, you can try to boot with
factory BIOS and compare the northbridge register value to figure
out any relation between these values and the DIMM configuration.

> >> ---------------
> >> The third issue is, VGA.
> >> I read the FreeVGA paper. Yes, it seems great.
> >> But such complicated technology is really necessary?
> >
> >I am afraid we have to do it this way. It is probably the only way
> >we can get VGA working without any vendor support.
> >
> >> For example, this guy succeeded to use normal VGA bios, although I failed.
> >> http://www.carbotpc.com/linux/index.html
> >
> >I think this one uses the old "switch back to 16-bit mode and back"
> >technology. It is actually much more complicated than an emulator.
> >
> >You can try to add VGA support by yourself. Please take a look at
> >arima/hdama and tyan/*. There is one problem you have to solve,
> >the VGA BIOS on EPIA makes some BIOS call back to the system BIOS,
> >you have to emulate this in the emulator (see pcibios.c).
> >
> Umm.. Then, how about porting LX1 VGA code to LX2?
> In my EPIA M/B, LX1 VGA init seems to work.

I don't think we are going to do that. The reason we are using the 
emulator is to eliminate the mode switch inside LB.

>                 --- Okajima, Jun. Tokyo, Japan.
Li-Ta Lo <ollie at lanl.gov>
Los Alamos National Lab

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