I blew away my GBSYSTEM directory cause I'm not smart. Oh snap, No system on HDD. Loaded up bootloader mode, tried to restore the GBSYTEM directory only to have the whole process go poorly. Now I have a GBSYSTEM, but it is full of bad files.
In linux (debian unstable), as root, run blkid, to find the /dev of your toshiba:
%: blkid
/dev/sdc1: LABEL="GIGABEAT" UUID="365D-2137" TYPE="vfat"
Then,
fsck.vfat -a /dev/sdc1
I actually also had to do a manual run:
fsck.vfat -r /dev/sdc1
This fixed the various errors in the filesystem! no reformat for me!
I copied over the GBSYSTEM and rockbox firmware, and back to pacbox I go
Thanks for rockbox you beautiful open source gods.