The box is a Leelbox Q2 (s905x p212 2g). Image used is Armbian_20.08_Arm-64_focal_current_5.7.15_desktop.img booting from SD.
I have followed instructions, set dtb to /boot/dtb/amlogic/meson-gxl-s905x-p212.dtb in extlinux/extlinux.conf and copied u-boot-s905x-s912 in u-boot.ext.
Now u-boot sets my mac-address to 4e:6b:62:04:f1:00 which is not correct, from u-boot console i can't set ethaddr property (error is can't overwrite). I also tried to convert dtb to dts, add local-mac-address (and mac-address) property to ethernet and convert this dts to a dtb used in extlinux.conf but this doesn't work, mac address is always overwritten (by uboot I guess).
Another issue is that activity/link leds on port are not working.
Every thing just works booting original android image from internal flash.