There was not enough working screen to set the wifi password without a lot of trial and error. Fortunately I had enough screen to scan for networks and select my AP. With the serial console I was able to hardcode the password in /usr/local/Kobo/configure_wpa_network.sh.
This file persists across boots.
I enabled telnet and ftp by following these Kobo Wifi hacking instructions, but editing them directly on the filesystem over the serial console instead of creating a Koboroot.tgz
I noticed that wget is on the default root filesystem, which seems like an easier way of doing things.
Debian Wheezy ARMEL packages run on the N647 and N647B models.
The i2c buses don’t seem to work with the standard Linux I2C tools like i2cdetect, etc.