Comment 17 for bug 1636838

Ok, here's a more verbose version of my testing procedure:

-take the rpi2 image: http://cdimage.ubuntu.com/ubuntu/releases/16.04/release/ubuntu-16.04-preinstalled-server-armhf+raspi2.img.xz

-after a fresh install, these are the pkgs version:

ubuntu@ubuntu:~$ dpkg -l | grep -e uboot -e flash-kernel -e firmware -e linux-raspi2
ii flash-kernel 3.0~rc.4ubuntu62 armhf utility to make certain embedded devices bootable
ii linux-firmware-raspi2 1.20151118+b70b451-0ubuntu1 armhf RaspberryPi2 GPU firmware and bootloaders
ii linux-raspi2 4.4.0.1009.9 armhf Complete Linux kernel for the BCM2709 architecture.

-enable proposed, apt-get update and apt-get dist-upgrade:

ubuntu@ubuntu:~$ dpkg -l | grep -e uboot -e flash-kernel -e firmware -e linux-raspi2
ii flash-kernel 3.0~rc.4ubuntu62.1.1 armhf utility to make certain embedded devices bootable
ii linux-firmware-raspi2 1.20161020-0ubuntu1~0.1 armhf RaspberryPi2 GPU firmware and bootloaders
ii linux-raspi2 4.4.0.1038.37 armhf Complete Linux kernel for the BCM2709 architecture.

same goes for 'apt-get upgrade' instead of 'dist-upgrade', except this time you won't get the newer kernel.