OFW sad face doesn't say why

[Mikus Grinbergs]

Happened to put in laptop BB a SD card copied over from laptop AA. 
Pushed power-on, laptop BB showed me a sad face and powered down.

Figured out why -- that SD card had a directory on it called 
/security, and in that directory there was a file called 
develop.sig.  Since this file's content did not match BB's identity, 
BB powered down.  I erased that file - then BB would boot o.k.


If you have a cheap SD card, and an enemy with an XO, why not create 
/security/develop.sig on that SD card, and surreptitiously insert 
that SD card into his OLPC - he would be extremely UNLIKELY to think 
of examining the sd-card-slot for the cause of his XO not booting.

If the OFW identified its reason for not proceeding with booting, 
this opportunity for mischief would not work.

mikus