locking the SD card

[Sameer Verma]

I discovered something interesting. I was running the XS-on-XO image
on a XO-1. The writes tend to slow things down, so I moved the
/library partition onto an external USB drive. I figured, if I lock
the SD card, the OS will be forced to act as read only on the card,
but that's not the case. Even after sliding the lock switch on the SD
card, root is able to write files to the partition.

cheers,
Sameer