[coreboot] Porting coreboot to Intel Atom (Silverthorne) & SCH US15W (Poulsbo) chipset

Ken.Fuchs at bench.com Ken.Fuchs at bench.com
Thu Apr 16 00:40:56 CEST 2009

bari wrote:

> There are several i945 + Atom boards available. This way you can
> develop and test Atom on a working chipset and then work on the
> US15W. 

In my opinion, porting US15W may not be worthwhile, since it doesn't
support the SPI bus which would allow use of SPI NOR flash.  US15W
supports FWH which Intel has already obsoleted, although It may have
contracted with third parties to supply FWH devices for this chip set.

Also, this chipset almost requires an embedded controller to handle
power and translate between FWH and SPI bus to support SPI NOR devices.
Intel does offer a CPLD solution that avoids the use of the embedded
controller, but the CPLD would only permit reading of the SPI NOR
flash and absolutely no writing of it.

The US15W also has it own microcode updating that the BIOS/firmware
must support.

The i945/ICH7M would be a far better final target for an Atom chipset
and has none of the above mentioned issues.  Of course you would need
to use Diamondville Atom rather Silverthorne Atom in this case.

Good luck with your Poulsbo (US15W) port, assuming you are willing to
spend 6-9 months on it.  It could be more or less than that depending
on the number of people working on it and their firmware experience.


Ken Fuchs

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