Corrupt PS3

CECHL01 on 3.56 OFW
software problem
used to run 3.55 CFW

So I was updating my 3.56 online and the power went out. I turn it back on and it's screwed up. So I use the emergency menu (power button, double beep, etc.) and none of the options work, at all.

"Restart System" -> PS3 restarts and goes back to "The system software cannot be run correctly. Press the PS button to try to restart the system."

"Restore Default Settings" -> Same as above.

"Restore File System" -> Same as above.

"Restore PS3 System" -> Same as above.

"Rebuild Database" -> "The hard disk cannot be accessed." (I did not ever swap the HDD)

"System Update" -> "The data is corrupted." (8002F2C5)

Is this fix-able? Do I simply have to reformat the hard drive using a PC, or do I need a flasher -- and is it still worth getting a flasher in order to get 4.21 CFW or, with the advent of the LV0 keys, is it worth holding off for an exploit and staying on OFW 3.56 provided I can fix this? If I need a flasher, I would prefer a solderless solution, I think CECHL01 is NOR-based.