This document explains how to manually upgrade U-Boot on the Edge-2L.
Transfer the U-Boot Debian package to your board and install it using the dpkg command.
The U-Boot Debian package is named linux-u-boot-edge-2l-vendor_xxxx-2017.09_arm64.deb, where xxxx represents the version number (e.g., 1.1.1).
$ sudo dpkg -i linux-u-boot-edge-2l-vendor_xxxx-2017.09_arm64.deb $ sync $ sudo reboot