[coreboot] suspend/resume in v3

[Rudolf Marek]

> Is it doable to determine coreboot RAM location at runtime?

Hmm I dont know how v3 works. But ACPI assumes that there must be 8MB from the 
1MB continuous, so maybe we can even do a hole after 8MB ;)
(and call it ACPI NVS, for example).

>> If anyone is worried about the "waste" of last MB. I think we can
>> hotplug the memory back to OS through ACPI, got some experimental
>> ASL code, but kernel panicked. Maybe it is there some glitch.
> 
> Then we can't suspend again. Seems problematic. Those who enable
> suspend/resume in our Kconfig will simply have to pay the cost of
> some RAM.

If the linux hotplug succeeds to free the memory again then it should work.
But I agree, ACPI is telling that there might be holes after first 8MB, so maybe 
we can put coreboot to any addr bigger then 8MB.

>> The code absolutely _must_ _not_ write to any other memory. No
>> strange AP stacks in random 0 - 640kb ;)
> 
> Right, this is my concern.

Yep cool.

Rudolf