[OLPC-devel] Secure BIOS on the OLPC

[Mark J. Foster]

I think that I may have identified a potential hole in the 
implementation discussed so far, in that folks have often stated that 
the BIOS becomes write-enabled on a "reboot". To be a little more 
specific, we could add a latch, as Richard suggested, but we could only 
open it up on a "cold boot", not a "reboot".  Otherwise, the problem is 
that software could reset the EC after the system is up, which would 
open up the write-protect.

Therefore, the "signal" that would open the write-protect pin is 
removing the battery, then plugging it back in.  It's also possible that 
holding down the power button for four seconds could do the trick, 
followed by pushing the power button again to do a cold power-on.

On second thought, is this really better than making kids hold down the 
spacebar for 4-5 seconds?