-chroot "$target" addgroup --gid 1000 grml
-chroot "$target" useradd -d /home/grml -m -s /bin/zsh -g 1000 grml
+USERNAME=''
+[ -r /etc/grml/grml-live.conf ] && . /etc/grml/grml-live.conf
+[ -n "$USERNAME" ] || USERNAME=grml
+
+chroot "$target" addgroup --gid 1000 $USERNAME
+chroot "$target" useradd -d /home/$USERNAME -m -s /bin/zsh -g 1000 $USERNAME