Check Release Note.
Linux 4.4 Images
NoteEdge Only support Ubuntu 18.04 for Linux 4.4.
Mainline Kernel Images
NoteEdge Only support Ubuntu 20.04 for Mainline Linux.
EMMC InstallationImages used to be flashed to onboard eMMC via Rockchip USB Burning Tool.
Check Upgrade Via USB Cable Documentation.
SD/USB InstallationImages used to be flashed to SD/USB storage.
Check Write SD Image To eMMC to write the image to onboard eMMC.