Your friends at #iPhone made a major breakthrough this morning.
we got a serial console working, here is how
the serial has the same pinouts as iPod serial
use a 6.8kish resistor from pin 21 to gnd
tie pin 11-sergnd to the real ground
use iphoneinterface to send the following commands in recovery mode:
setenv debug-uarts 1
saveenv
reboot
that should work
IT GIVES YOU A FULL INTERACTIVE SHELL
I REPEAT, A FULL INTERACTIVE SHELL