#mount the relevant partitions of the drive
sudo mount /dev/sda2 /mnt/
sudo mount /dev/sda1 /mnt/boot/efi/
for i in /dev /dev/pts /proc /sys /run; do sudo mount -B $i /mnt/$i; done

#chroot time

for i in /mnt/run /mnt/sys /mnt/proc /mnt/dev/pts /mnt/dev; do sudo umount -l $i; done
sudo umount /dev/sda1
sudo umount /dev/sda2