[LinuxBIOS] YEAH! EPIA WORKS!

[Li-Ta Lo]

On Sun, 2005-07-24 at 12:33 +0900, Jun OKAJIMA wrote:
> Hello all guys here.
> 
> Finally, the very foolish guy in Tokyo has succeeded to run
> LX2 on my EPIA M/B. Thank you all. Thanks for all helps. Thank you!!!.
> 
> But, of course, there are problems and questions.
> 
> ---------------
> first, the biggest issue is, DIMMs are really picky. The M/B
> is natively picky, I mean, even with Award BIOS, it is picky.
> but the problem is much more serious with LX2.
> I tested with two EPIA M/B and 5 DIMMs which all
> are confirmed to work well with Award BIOS. And the result
> is too much great. Only one combination worked in these
> 10 combinations. Guys, can you help?
> 
> 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. 


> --------------
> The second issue is, booting time. It is very fast before
> a kernel loaded, but after this, there are three glitches.
> I know at least two of them are not LX2 issue, but I hope any advice.
> 
> 1. Just after "Jumping to entry point...".
> Probably this waiting is caused by "Uncompressing Linux kernel",
> but it is much slower than normal booting. Takes about 2 sec.
> 
> 2. 
>    "Console: colour dummy device 80x25
>          <---- here.
>     Memory: 128128k/131072k available"
> This comes from memory checking? It takes about 1 sec.
> 

The cache is not enable at all due to some mistake in the mainboard
Config.lb. I think I have a correct one but I was busy doing porting
to some other mainboard and didn't have time to test it. I will try
to do it next week.

> 3. IDE recognizing.
>    I added "ide0=0x1f0,0x3f6,14 ide1=noprobe", but it takes about 2 secs.
> 
> 
> ---------------
> 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).

> Or, just using Xfree86 driver doesnt work?
> 

No. The Xfree86 driver is too stupid to do a full hardware 
initialization.

-- 
Li-Ta Lo <ollie at lanl.gov>
Los Alamos National Lab