On Sun, 14 Jan 2001, Brian Stephenson wrote:
> But looking at the romimages and the mkrom program there is a jump
> instruction near the end of the flash to linuxbios code located in the
> last 64k and the kernel located at the start, this I dont understand.
This is really my fault (again, gee this happens a lot). For the docipl
case, the romimage is not used. I need to fix this. Forget the romimage.
Forget mkrom for docipl.
> If I place a 128K flash in the bios socket:
^^^^
Does you no good, too small, but ...
>
> 1: where should the reset vector be, I assumed it would be at FE000 +
> 1FF0 = FFFF0
> which is about 8K from start of flash.
Let's go WRT the base of the 128K. The reset vector is at 1fff0.
>
> 2: as I understand it the processor can only access 1Meg memory, FE000
> to
> FFFFF is 8k, where is the rest located, I had a look at the
> datasheet for SiS
> 950 and there is something about bios segment FFF80000->FFFDFFFF,
> FFFE0000->FFFEFFFF. all pretty confusing to me.
No, the chipsets when it comes up let you get to f0000-fffff, which is
64K. We turn on protected mode right away, and jump to a true 32-bit
address.
> I would be happy just to get linuxbios booted out of flash for now (no
> kernel), anyone with some tips??
Just don't do it. We've left flash behind on the 630, I have not tried it
in months and neither has SiS, and in fact with some of Ollie's changes to
the SiS northbridge Config you can't build flash any more. Just use the
DoC. Obviously as you can see there is some junk left in the Makefile from
the flash days, but I have tried going back and it's not worth it.
I need to clarify this in the HOWTO. But we've tried that HOWTO to death
at this point, it works, so that's how you should start now.
ron
