[LinuxBIOS] #26: flashrom: Support for PIIX4/PIIX4E/PIIX4M

Segher Boessenkool segher at kernel.crashing.org
Sun Nov 5 04:35:54 CET 2006

> I don't work well with web applications but tried submitting a note
> via trac anyway, only to be rejected as potential spam, according to
> "Akismet". I would love some way to interact with trac that is not
> web based. Does anyone know?

I don't know but I'd sure like it.

>>  Just curious: in the datasheet I see three BIOS-related bits, "Lower
>>  BIOS Enable", "Extended BIOS Enable", and "1-Meg Extended BIOS
>>  Enable".
>>  I only enabled the "Extended BIOS Enable" (FFF80000-FFFDFFFF); do I
>>  need to touch one of the others, too?
> That enables top-512kb -> top-128k so I think you'll want to touch
> more bits. 1-Meg sounds good. What is Lower?

Sounds like the legacy BIOS range at e00000..fffff, aliased to
fffe0000..ffffffff (or aliased the other way around, whatever).

One bit gives you access to 128kB ROM space, two gets you 512kB,
all three makes 1MB.  Enable all you need to map your flash but
not more (as it eats address space and potentially even DRAM).
In the flashrom tool you probably want to enable as large a window
as possible of course.


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