Make sure you download the exact version for your board revision. Using the wrong firmware can brick the box.
Once you have downloaded your chosen firmware (usually a .zip for recovery or .xml for HiTool), follow this guide. hi3798 firmware top
To update or flash firmware for devices using the HiSilicon Hi3798 Make sure you download the exact version for
: Most Hi3798 devices can be updated by placing an update.zip file on a FAT32-formatted USB drive. You often need to hold the "reset" button (sometimes hidden inside the AV port) while plugging in the power to trigger the update. hi3798 firmware top