updategrubon

#!/bin/bash

if [ "$(id -u)" != "0" ]; then
  exec sudo "$0" "$@"
fi

user="$SUDO_USER"
target="$1"

mkdir /media/$user/target

mount $target"2" /media/$user/target
mount $target"1" /media/$user/target/boot/efi

for i in /sys /run /dev /proc; do mount --bind "$i" "/media/$user/target$i"; done

chroot /media/$user/target/ /bin/bash -- << EOT
#    grub-install $target (not working? oh well, updating the existing seems sufficient, at least for now)
    update-grub
EOT

for i in /proc /dev /run /sys; do sudo umount "/media/$user/target$i"; done

sudo umount $target"1"
sudo umount $target"2"

sudo rmdir /media/$user/target