hi hamak,
I was just looking at digital microscopes using a RPi this morning. This thread will come in very handy!
Just a couple of points:
1. Heads up, firmware-rpi3-wireless.tcz will be renamed to firmware-rpi-wifi.tcz in future piCore.
2. I think when you do a "tce-load -wi extn" it automatically adds extn to onboot.lst
3. Typo: "filetool.s -b" should be "filetool.sh -b". Missing "h".
regards
Greg