Hi Michael,
When connecting Putty to the serial port, the keyboard configuration called 'SCO' in Putty's keyboard settings seems to generate the codes that work the best in EFI and Linux - including the proper code for F7 in EFI. Don't ask me why, the terminal stuff is all black magic to me.
Once at the Linux serial console I also find the following command very useful:
stty rows 50 columns 150 # for instance
Marc
