Grub config to allow load overrides from /grub_extra.cfg if present

45_grub_extra.cfg

#!/bin/sh
# Searches all drives for a file named grub_extra.cfg in the root dir
# and includes it after all other config files.
# Can be used to force override any variables
# Example /grub_extra.cfg:
# set default=1

cat <<EOF
search --file --set extra_cfg_dev /grub_extra.cfg

if [ "\${extra_cfg_dev}" ]; then
	set extra_cfg_file="(\${extra_cfg_dev})/grub_extra.cfg"
	echo "Including \${extra_cfg_file}"
	source "\${extra_cfg_file}"
	echo "Default is now \${default}"
fi

EOF