There is a 64-bit kernel 4.4 using the same CPU here: https://github.com/SamsungARTIK/linux-artik/commits/A710/v4.4 u-boot here: https://github.com/SamsungARTIK/u-boot-artik/tree/A710_os_2.0.0 As far as Nexell is concerned, job done! They have delivered the kernel. Integrating that kernel to work wi...

I compile and change my kernels all the time. All I do to change kernel is: cp /path/to/compiled/uImage /boot/uImage.hdmi Note that there are two uImage. One for HDMI and one for LVDS. I have no idea what the inbuilt package manager will do when upgrading kernel but you may need to copy it to uImage...