[CuBox-i4Pro and X11 GPU support]

I was also able to get hardware acceleration going following the same howto. http://git.arm.linux.org.uk/cgit/xf86-video-armada.git/tree/README?h=unstable-devel The one thing I did different is that I used the Etnaviv GPU driver. Here is the steps I took.

cd Downloads
git clone git://git.armlinux.org.uk/~rmk/libdrm-armada.git/
cd armada/
ls -l
cd libdrm-armada/
ls
mkdir m4; autoreconf -f -i
./configure --prefix=/usr --enable-etnaviv
make
sudo make install
cd ..
ls
git clone https://github.com/laanwj/etna_viv.git
sudo git clone https://github.com/laanwj/etna_viv.git
ETNA_SRC=$PWD/etna_viv
git clone git://git.armlinux.org.uk/~rmk/xf86-video-armada.git/
sudo git clone git://git.armlinux.org.uk/~rmk/xf86-video-armada.git/
ls
cd xf86-video-armada/
ls
git checkout unstable-devel
echo $ETNA_SRC
# If make does not work the first time you can "make clean" after you have fixed the problems

./autogen.sh --prefix=/usr --disable-vivante --enable-etnaviv --with-etnaviv-source=$ETNA_SRC
make
sudo make install
ls
cd conf/
ls
vim xorg-sample.conf 
sudo cp xorg-sample.conf /etc/X11/xorg.conf
# We need to install a more recent version of libgl1-mesa-dri to get the Etnaviv GPU driver. 
# This will install version 13.0.6 which is not the latest. To get the latest we will have to compile it ourself.
# Use apt pinning for this.
# Create files /etc/apt/preferences if it does not already exist.
# Add this
Package: *
Pin: release a=stable
Pin-Priority: 1000

Package: *
Pin: release a=unstable
Pin-Priority: 2

Package: libgl1-mesa-dri
Pin: release a=unstable
Pin-Priority: 1001

# You may need to add all of libgl1-mesa-dri dependecies as well to this apt pinning preferences.


# Add this to /etc/apt/sources.list
deb http://ftp.it.debian.org/debian unstable main contrib non-free
# Then install libgl1-mesa-dri
apt-get update
apt-get -t unstable install libgl1-mesa-dri
reboot

glxgears -info

I am on Armbian Stretch with kernel 4.13.16.

Please correct me if I miss spoken.