[LinuxBIOS] 440BX progress.

[Segher Boessenkool]

> Hint: Try testing the lower memory:
>
>   ram_check(0x10000000, 0x2000000);
>   is going for 256-512 Megs.

Ah, there's the (or a) problem.  There's a zero missing.
No memory was tested at all.

> The LinuxBIOS image is copied to _RAMBASE which normally defaults to
> 0x4000 (@16k). So you might have 2 dimms a 256M and while the upper one
> works, the lower one doesnt.

Yeah.

> In the end the ram_check() function does not reliably test your memory.
> It will not detect whether your memory works, but it will detect 
> whether
> it fails ;-)

And not always, either.

> Also note: the order in which your registers are set may play a role.
> For example there might be a register with a DRAM_ENABLE bit which must
> be set last, after all other DRAM related bits are set, or the values
> set later on might be ignored.

Yes.  And you often have to wait for certain bits to flip
before you write other bits, etc.


Segher