Clone the Linux_Upgrade_Tool:

git clone https://github.com/vicharak-in/Linux_Upgrade_Tool

Copy upgrade_tool to /usr/local/bin:

$ sudo cp Linux_Upgrade_Tool/upgrade_tool /usr/local/bin/

Remove the battery and USB cable from the Fusion Gateway

Press and hold the button near the power supply (from the set of 3 buttons)

Insert the battery

Plug the USB cable

Run the flashing command:

$ sudo upgrade_tool ef update.img

• BrainDamage