/etc/grub.d/ Current File: //etc/grub.d/30_uefi-firmware
#! /bin/sh
set -e

# grub-mkconfig helper script.
# Copyright (C) 2012  Free Software Foundation, Inc.
#
# GRUB is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# GRUB is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with GRUB.  If not, see <http://www.gnu.org/licenses/>.

prefix="/usr"
exec_prefix="/usr"
datarootdir="/usr/share"

export TEXTDOMAIN=grub
export TEXTDOMAINDIR="${datarootdir}/locale"

. "${datarootdir}/grub/grub-mkconfig_lib"

efi_vars_dir=/sys/firmware/efi/vars
EFI_GLOBAL_VARIABLE=8be4df61-93ca-11d2-aa0d-00e098032b8c
OsIndications="$efi_vars_dir/OsIndicationsSupported-$EFI_GLOBAL_VARIABLE/data"

if [ -e "$OsIndications" ] && \
   [ "$(( $(printf 0x%x \'"$(cat $OsIndications | cut -b1)") & 1 ))" = 1 ]; then
  LABEL="UEFI Firmware Settings"

  gettext_printf "Adding boot menu entry for UEFI Firmware Settings\n" >&2

  onstr="$(gettext_printf "(on %s)" "${DEVICE}")"

  cat << EOF
menuentry '$LABEL' \$menuentry_id_option 'uefi-firmware' {
	fwsetup
}
EOF
fi