[OLPC-devel] Secure BIOS on the OLPC

[Mark J. Foster]

Ivan Krstić wrote:
> Mark J. Foster wrote:
>   
> This might be an obvious question, but is there a reason we allow
> software to reset the EC
Not to worry, it's a non-obvious answer! ;-)  The reason that we must be 
able to reset the EC is to stop it from executing code while writing to 
the Flash chip.  Since the EC and the system BIOS share the SPI Flash, 
the EC would otherwise be continually performing code fetches from the 
same Flash that you're trying to write to.  That's why the system must 
be able to reset and control the EC chip.