[coreboot] Experiments with disabling the ME on Sandybridge x230

[Peter Stuge]

Trammell Hudson wrote:
> I've experimented with clearing additional bits, from 0x3000 to 0x10000
> with the same results.  If I were really motivated I might binary search
> how much of the firmware it needs...

That would be interesting.


> > > ME: Current Working State   : Recovery
> > > ME: Current Operation State : Bring up
> > > ME: Current Operation Mode  : Normal
> > > ME: Error Code              : No Error
> > > ME: Progress Phase          : BUP Phase
> > ..
> > > ME: Current Working State   : Reset
> > > ME: Current Operation State : Preboot
> > > ME: Current Operation Mode  : Normal
> > > ME: Error Code              : No Error
> > > ME: Progress Phase          : ROM Phase
> > 
> > How do the above change, if at all, with unchanged flash?
> 
> With the firmware partition table restored:
..
> ME: Current Working State   : Normal
> ME: Current Operation State : Bring up
> ME: Current Operation Mode  : Normal
> ME: Error Code              : No Error
> ME: Progress Phase          : BUP Phase
..
> ME: Current Working State   : Normal
> ME: Current Operation State : M0 with UMA
> ME: Current Operation Mode  : Normal
> ME: Error Code              : No Error
> ME: Progress Phase          : Host Communication

So the ME is clearly in a different state, which is interesting.

But, if your goal is to avoid the ME interfering with the system then
I guess there is still some way to go, as long the ME PCI interface
works. (Where the above state comes from.)

(Spoiler alert: I don't think it's possible; read the book.)


//Peter