Working with images

#Mount image to first avaliable loop device
sudo losetup -fP --show pivilion.img                                

#Mount second partition (linux partition for Pi) to /mnt
mount /dev/loop1p2 /mnt

#Copy some files
cp -R /files/blah/* /mnt/var/www/

#Or chroot and install some software 

install qemu-user-static-binfmt
chroot /mnt         

#Unmount and cleanup

sudo umount /dev/loop2p2
sudo losetup -D /dev/loop2