I have an old image from my Raspberry Pi 2 (Jessie Lite) and this works fine on my Raspberry Pi 2 running the BCM2836 processor, however I ordered a new Pi 2 and it seems that they have changed to the BCM2837 processor for the Pi 2.
http://hackaday.com/2016/11/21/the-raspberry-pi-2-gets-a-processor-upgrade/
When I boot the same SD card on the new Pi 2 it gets stuck on the rainbow screen.
I know I need to do an update using the old Pi 2 to get it to work on the new Pi 2, but what command do I need to update the absolute minimum for this to work?
sudo apt update && sudo apt upgrade
?