- cat >$FAI_ROOT/etc/grub.d/40_custom <<EOF
-#!/bin/sh
-exec tail -n +3 \$0
-# This file provides an easy way to add custom menu entries. Simply type the
-# menu entries you want to add after this comment. Be careful not to change
-# the 'exec tail' line above.
-
-# https://www.coreboot.org/Serial_console # tty
-# but removed unneeded stuff
-
-serial --speed=$speed
-terminal_input --append serial
-terminal_output --append serial
-EOF
-
-
- chroot $FAI_ROOT bash <<EOF
-set -eE -o pipefail
-# https://askubuntu.com/questions/33416/how-do-i-disable-the-boot-splash-screen-and-only-show-kernel-and-boot-text-inst
-
-sed -ri 's/(^GRUB_CMDLINE_LINUX_DEFAULT=")quiet/\1/;s/^(GRUB_CMDLINE_LINUX_DEFAULT=".*) quiet([ "])/\1\2/' /etc/default/grub
-sed -ri 's/(^GRUB_CMDLINE_LINUX_DEFAULT=")splash/\1/;s/^(GRUB_CMDLINE_LINUX_DEFAULT=".*) splash([ "])/\1\2/' /etc/default/grub
-
-for arg in $cmdline; do
- if ! grep "^GRUB_CMDLINE_LINUX_DEFAULT=.*[\" ]${arg//./\\.}[\" ]" /etc/default/grub; then
- sed -ri "s/^GRUB_CMDLINE_LINUX_DEFAULT=\"(.*)/GRUB_CMDLINE_LINUX_DEFAULT=\"$arg \1/" /etc/default/grub
- fi
-done
-
-if grep -qF "$cmdline" /etc/default/grub; then
- # already set things, exit
- exit 0
-fi
-sed -ri 's/^ *GRUB_CMDLINE_LINUX_DEFAULT=.*/GRUB_CMDLINE_LINUX_DEFAULT="$cmdline"/' /etc/default/grub
-# on xenial, no grub is displayed at all. fix that.
-# found just by noticing this in the config file, and a
-# warning about it in error.log
-sed -i '/^ *GRUB_HIDDEN_TIMEOUT/d' /etc/default/grub
-
-if type -P update-grub2 &>/dev/null; then
- update-grub2
-else
- update-grub
-fi
-
-EOF