The following section goes into detail of the firmware recovery process for Komikan when it does not boot any further than U-Boot. This can happen during an accidental shutdown during the firmware upgrade process or any corrupted system files. Some recovery methods will require LAN and serial access. Note: any configuration changes made previously will be cleared!
Recover via U-Boot
ATENTION! It is possible to brick your board while making changes inside the bootloader so make sure you are entering correct commands. If you make a mistake while typing use CTRL+C instead of backspace!
sudo apt-get install tftp-hpa
2. Connect to device via picocom.
picocom -b 115200 /dev/ttyUSB0
3. Reboot device and enter bootloader menu by pressing ESC several times while device boots.
4. Check for ip address.
5. Exit from picocom, return to PC shell. Press <CTRL+A> <CTRL+X> to exit from picocom.
6. Add address from the same subnet as device address.
sudo ip a a 192.168.1.5/24 dev eth2
7. Execute this recovery command.
tftp 192.168.1.6 -m binary -c put <firmware>
8. Enter picocom to check for upgrade process.