To upgrade the firmware you'll need a TFTP client. Please use utftp client for Linux, which was tested and works correctly with our devices. Other TFTP clients should also work.
Untar and compile the utftp:
tar xvf utftpd-0.2.4.tar.gz cd utftpd-0.2.4 make make install
We advise to connect the device directly to the PC, with no other traffic present. Although it's possible to upgrade firmware remotely (over the Internet), it would be easier to see what is displayed on the LCD and access the serial console if necessary.
Connect to the device and enable TFTP access:
Tahoe> tftp on
Send the 'erase' file (zero-length) to erase the Flash memory:
utftp -p 10.0.0.1 erase
(replace '10.0.0.1' with device's IP address)
After a few seconds the Flash memory is erased.
WARNING: if your device had firmware version 1.2.8 or older do not power off or reboot the device until you complete writing the new firmware. It has no firmware at all at the moment and won't boot again. You don't have to care about that with newer versions (1.2.9 and later) as there is always a bootstrap which is never erased and allows a firmware recovery in case of accidental reboot during the upgrade.
Send the new firmware under the name 'flash':
utftp -p 10.0.0.1 flash t680-1.2.9.bin
(you may need to change 't680-1.2.9.bin' to another filename)
You'll see the programming progress on the LCD. If something goes wrong, repeat the procedure by first erasing the Flash and then programming again.
