[coreboot] coreboot and embedded controllers, for example OLPC and its OpenEC code

Frieder Ferlemann frieder.ferlemann at web.de
Thu Jun 19 08:40:32 CEST 2008

Hi Peter,

Peter Stuge schrieb:
> Just a little tidbit..
> On Thu, Jun 19, 2008 at 01:22:47AM +0200, Frieder Ferlemann wrote:
>> Yep, let's see what happens. OpenEC is GPL'ed so it is there
>> to stay and it is waiting for a slightly better chance than
>> OLPC turned out to be.
> Me and Uwe ran into a desktop board with this SMSC superio..
>> And OpenEC was written with portability in mind. While it
>> specifically targets an ENE KB3700 (with its 8051 based core)
>> the source is also compileable with gcc.
> The superio included an 8051. The 8051 did not have it's own program
> memory, it's program was stored in the BIOS flash.
> When the board powered up, only the 8051 was running. It needed
> software to do some stuff, and only then could it negotiate release
> of the main CPU reset.

This seems close to the EC on the XO.

> We found some PDF files and it did seem within our reach to get the
> 8051 to at least power up the CPU, but it was the heart of the
> superio, so I believe most superio functions would be unavailable
> until there was more 8051 code.

On the XO both the host CPU (Geode) and the EC could access special
function registers (those which were mapped into xdata space on the EC).
(Access to these registers was later switched off for the host CPU due
to security implications)

Out of curiosity, which SMSC superio was it?


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