The actual panic error you're seeing there shows it's a filesystem error. You can probably recover form that using fsck from single user mode if you have not flashed it yet:
At the SG-1100 console press any key to interrupt the boot loader when you see:
Hit [Enter] to boot immediately, or any other key for command prompt.
At the 'loader>' prompt enter: boot -s
That will boot in single user mode to a question asking for a path to the shell, just press return to reach the # prompt.
At the # prompt run the following command: fsck -y /
Run the fsck command at least 3 times; Repeat the command until no errors are reported, even if fsck claims the filesystem has been marked "clean".
Reboot by running: reboot
Steve