Hello,

> Finished writing the files to a USB2 flash drive, typed eject sd0, it 
> wrote for a few seconds and then the whole system locked up. Nothing on 
> Xconsole, the keyboard and mouse are inoperative. Can't be pinged. 
> ddbonpanic=0 but it didn't do a dump, Seems to be repeatable, unable to 
> get into DB, and even if I could, it's a USB keyboard which won't work.

Well, either try to umount your partition before dismounting the key, or 
you have stumbled on the same bug as me : sometimes, the USB 2 code lose 
a transaction, gets desynchronized, and hangs while trying to reset the 
BBB layer.

In fact, this almost never happens while reading, but almost immediately 
while writing.

Vincent