Patched file in the grub2 Ubuntu package (see: http://askubuntu.com/a/498281/197497 and https://bugs.launchpad.net/ubuntu/+source/grub2/+bug/1274320)

00_header_patched

#! /bin/sh
set -e

# grub-mkconfig helper script.
# Copyright (C) 2006,2007,2008,2009,2010  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"
grub_lang=`echo $LANG | cut -d . -f 1`
grubdir="`echo "/boot/grub" | sed 's,//*,/,g'`"
quick_boot="1"

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

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

# Do this as early as possible, since other commands might depend on it.
# (e.g. the `loadfont' command might need lvm or raid modules)
for i in ${GRUB_PRELOAD_MODULES} ; do
  echo "insmod $i"
done

if [ "x${GRUB_DEFAULT}" = "x" ] ; then GRUB_DEFAULT=0 ; fi
if [ "x${GRUB_DEFAULT}" = "xsaved" ] ; then GRUB_DEFAULT='${saved_entry}' ; fi
if [ "x${GRUB_TIMEOUT}" = "x" ] ; then GRUB_TIMEOUT=5 ; fi
if [ "x${GRUB_GFXMODE}" = "x" ] ; then GRUB_GFXMODE=auto ; fi

if [ "x${GRUB_DEFAULT_BUTTON}" = "x" ] ; then GRUB_DEFAULT_BUTTON="$GRUB_DEFAULT" ; fi
if [ "x${GRUB_DEFAULT_BUTTON}" = "xsaved" ] ; then GRUB_DEFAULT_BUTTON='${saved_entry}' ; fi
if [ "x${GRUB_TIMEOUT_BUTTON}" = "x" ] ; then GRUB_TIMEOUT_BUTTON="$GRUB_TIMEOUT" ; fi

cat << EOF
if [ -s \$prefix/grubenv ]; then
  set have_grubenv=true
  load_env
fi
EOF
if [ "x$GRUB_BUTTON_CMOS_ADDRESS" != "x" ]; then
    cat <<EOF
if cmostest $GRUB_BUTTON_CMOS_ADDRESS ; then
   set default="${GRUB_DEFAULT_BUTTON}"
elif [ "\${next_entry}" ] ; then
   set default="\${next_entry}"
   set next_entry=
   save_env next_entry
   set boot_once=true
else
   set default="${GRUB_DEFAULT}"
fi
EOF
else
    cat <<EOF
if [ "\${next_entry}" ] ; then
   set default="\${next_entry}"
   set next_entry=
   save_env next_entry
   set boot_once=true
else
   set default="${GRUB_DEFAULT}"
fi
EOF
fi
cat <<EOF

if [ x"\${feature_menuentry_id}" = xy ]; then
  menuentry_id_option="--id"
else
  menuentry_id_option=""
fi

export menuentry_id_option

if [ "\${prev_saved_entry}" ]; then
  set saved_entry="\${prev_saved_entry}"
  save_env saved_entry
  set prev_saved_entry=
  save_env prev_saved_entry
  set boot_once=true
fi

function savedefault {
  if [ -z "\${boot_once}" ]; then
    saved_entry="\${chosen}"
    save_env saved_entry
  fi
}
EOF

    if [ "$quick_boot" = 1 ]; then
      cat <<EOF
    function recordfail {
      set recordfail=1
EOF

    check_writable () {
        abstractions="$(grub-probe --target=abstraction "${grubdir}")"
        for abstraction in $abstractions; do
          case "$abstraction" in
          diskfilter | lvm)
            cat <<EOF
        # GRUB lacks write support for $abstraction, so recordfail support is disabled.
EOF
            return
            ;;
          esac
        done

        FS="$(grub-probe --target=fs "${grubdir}")"
        case "$FS" in
          btrfs | cpiofs | newc | odc | romfs | squash4 | tarfs | zfs)
        	  cat <<EOF
        # GRUB lacks write support for $FS, so recordfail support is disabled.
EOF
          return
          ;;
        esac

        cat <<EOF
      if [ -n "\${have_grubenv}" ]; then if [ -z "\${boot_once}" ]; then save_env recordfail; fi; fi
EOF
    }

    check_writable

      cat <<EOF
    }
EOF
    fi

cat <<EOF
function load_video {
EOF
if [ -n "${GRUB_VIDEO_BACKEND}" ]; then
    cat <<EOF
  insmod ${GRUB_VIDEO_BACKEND}
EOF
else
# If all_video.mod isn't available load all modules available
# with versions prior to introduction of all_video.mod
cat <<EOF
  if [ x\$feature_all_video_module = xy ]; then
    insmod all_video
  else
    insmod efi_gop
    insmod efi_uga
    insmod ieee1275_fb
    insmod vbe
    insmod vga
    insmod video_bochs
    insmod video_cirrus
  fi
EOF
fi
cat <<EOF
}

EOF

serial=0;
gfxterm=0;
for x in ${GRUB_TERMINAL_INPUT} ${GRUB_TERMINAL_OUTPUT}; do
    if [ xserial = "x$x" ]; then
	serial=1;
    fi
    if [ xgfxterm = "x$x" ]; then
	gfxterm=1;
    fi
done

if [ "x$serial" = x1 ]; then
    if [ "x${GRUB_SERIAL_COMMAND}" = "x" ] ; then
	grub_warn "$(gettext "Requested serial terminal but GRUB_SERIAL_COMMAND is unspecified. Default parameters will be used.")"
	GRUB_SERIAL_COMMAND=serial
    fi
    echo "${GRUB_SERIAL_COMMAND}"
fi

if [ "x$gfxterm" = x1 ]; then
    if [ -n "$GRUB_FONT" ] ; then
       # Make the font accessible
       prepare_grub_to_access_device `${grub_probe} --target=device "${GRUB_FONT}"`
    cat << EOF
if loadfont `make_system_path_relative_to_its_root "${GRUB_FONT}"` ; then
EOF
    else
	for dir in "${pkgdatadir}" "`echo '/boot/grub' | sed "s,//*,/,g"`" /usr/share/grub ; do
	    for basename in unicode unifont ascii; do
		path="${dir}/${basename}.pf2"
		if is_path_readable_by_grub "${path}" > /dev/null ; then
		    font_path="${path}"
		else
		    continue
		fi
		break 2
	    done
	done
	if [ -n "${font_path}" ] ; then
    cat << EOF
if [ x\$feature_default_font_path = xy ] ; then
   font=unicode
else
EOF
                # Make the font accessible
		prepare_grub_to_access_device `${grub_probe} --target=device "${font_path}"`
    cat << EOF
    font="`make_system_path_relative_to_its_root "${font_path}"`"
fi

if loadfont \$font ; then
EOF
	    else
    cat << EOF
if loadfont unicode ; then
EOF
	    fi
	fi

    cat << EOF
  set gfxmode=${GRUB_GFXMODE}
  load_video
  insmod gfxterm
EOF

# Gettext variables and module
if [ "x${LANG}" != "xC" ] &&  [ "x${LANG}" != "x" ]; then
  cat << EOF
  set locale_dir=\$prefix/locale
  set lang=${grub_lang}
  insmod gettext
EOF
fi

cat <<EOF
fi
EOF
fi

case x${GRUB_TERMINAL_INPUT} in
  x)
    # Just use the native terminal
  ;;
  x*)
    cat << EOF
terminal_input ${GRUB_TERMINAL_INPUT}
EOF
  ;;
esac

case x${GRUB_TERMINAL_OUTPUT} in
  x)
    # Just use the native terminal
  ;;
  x*)
    cat << EOF
terminal_output ${GRUB_TERMINAL_OUTPUT}
EOF
  ;;
esac

if [ "x$gfxterm" = x1 ]; then
    if [ "x$GRUB_THEME" != x ] && [ -f "$GRUB_THEME" ] \
	&& is_path_readable_by_grub "$GRUB_THEME"; then
	gettext_printf "Found theme: %s\n" "$GRUB_THEME" >&2

	prepare_grub_to_access_device `${grub_probe} --target=device "$GRUB_THEME"`
	cat << EOF
insmod gfxmenu
EOF
	themedir="`dirname "$GRUB_THEME"`"
	for x in "$themedir"/*.pf2 "$themedir"/f/*.pf2; do
	    if [ -f "$x" ]; then
		cat << EOF
loadfont (\$root)`make_system_path_relative_to_its_root $x`
EOF
	    fi
	done
	if [ x"`echo "$themedir"/*.jpg`" != x"$themedir/*.jpg" ] || [ x"`echo "$themedir"/*.jpeg`" != x"$themedir/*.jpeg" ]; then
	    cat << EOF
insmod jpeg
EOF
	fi
	if [ x"`echo "$themedir"/*.png`" != x"$themedir/*.png" ]; then
	    cat << EOF
insmod png
EOF
	fi
	if [ x"`echo "$themedir"/*.tga`" != x"$themedir/*.tga" ]; then
	    cat << EOF
insmod tga
EOF
	fi
	    
	cat << EOF
set theme=(\$root)`make_system_path_relative_to_its_root $GRUB_THEME`
export theme
EOF
    elif [ "x$GRUB_BACKGROUND" != x ] && [ -f "$GRUB_BACKGROUND" ] \
	    && is_path_readable_by_grub "$GRUB_BACKGROUND"; then
	gettext_printf "Found background: %s\n" "$GRUB_BACKGROUND" >&2
	case "$GRUB_BACKGROUND" in 
	    *.png)         reader=png ;;
	    *.tga)         reader=tga ;;
	    *.jpg|*.jpeg)  reader=jpeg ;;
	    *)             gettext "Unsupported image format" >&2; echo >&2; exit 1 ;;
	esac
	prepare_grub_to_access_device `${grub_probe} --target=device "$GRUB_BACKGROUND"`
	cat << EOF
insmod $reader
background_image -m stretch `make_system_path_relative_to_its_root "$GRUB_BACKGROUND"`
EOF
    fi
fi

make_timeout ()
{
    cat << EOF
if [ "\${recordfail}" = 1 ] ; then
  set timeout=${GRUB_RECORDFAIL_TIMEOUT:-30}
else
EOF
    if [ "x${3}" != "x" ] ; then
	timeout="${2}"
	style="${3}"
    elif [ "x${1}" != "x" ] && \
	 ([ "$quick_boot" = 1 ] || [ "x${1}" != "x0" ]) ; then
	# Handle the deprecated GRUB_HIDDEN_TIMEOUT scheme.
	timeout="${1}"
	if [ "x${2}" != "x0" ] ; then
	    grub_warn "$(gettext "Setting GRUB_TIMEOUT to a non-zero value when GRUB_HIDDEN_TIMEOUT is set is no longer supported.")"
	fi
	if [ "x${GRUB_HIDDEN_TIMEOUT_QUIET}" = "xtrue" ] ; then
	    style="hidden"
	    verbose=
	else
	    style="countdown"
	    verbose=" --verbose"
	fi
    else
	# No hidden timeout, so treat as GRUB_TIMEOUT_STYLE=menu
	timeout="${2}"
	style="menu"
    fi
    cat << EOF
  if [ x\$feature_timeout_style = xy ] ; then
    set timeout_style=${style}
    set timeout=${timeout}
EOF
    if [ "x${style}" = "xmenu" ] ; then
	cat << EOF
  # Fallback normal timeout code in case the timeout_style feature is
  # unavailable.
  else
    set timeout=${timeout}
EOF
    else
	cat << EOF
  # Fallback hidden-timeout code in case the timeout_style feature is
  # unavailable.
  elif sleep${verbose} --interruptible ${timeout} ; then
    set timeout=0
EOF
    fi
    cat << EOF
  fi
fi
EOF
}

if [ "x$GRUB_BUTTON_CMOS_ADDRESS" != "x" ]; then
    cat <<EOF
if cmostest $GRUB_BUTTON_CMOS_ADDRESS ; then
EOF
make_timeout "${GRUB_HIDDEN_TIMEOUT_BUTTON}" "${GRUB_TIMEOUT_BUTTON}" "${GRUB_TIMEOUT_STYLE_BUTTON}"
echo else
make_timeout "${GRUB_HIDDEN_TIMEOUT}" "${GRUB_TIMEOUT}" "${GRUB_TIMEOUT_STYLE}"
echo fi
else
make_timeout "${GRUB_HIDDEN_TIMEOUT}" "${GRUB_TIMEOUT}" "${GRUB_TIMEOUT_STYLE}"
fi

if [ "x$GRUB_BUTTON_CMOS_ADDRESS" != "x" ] && [ "x$GRUB_BUTTON_CMOS_CLEAN" = "xyes" ]; then
    cat <<EOF
cmosclean $GRUB_BUTTON_CMOS_ADDRESS
EOF
fi

# Play an initial tune
if [ "x${GRUB_INIT_TUNE}" != "x" ] ; then
  echo "play ${GRUB_INIT_TUNE}"
fi

if [ "x${GRUB_BADRAM}" != "x" ] ; then
  echo "badram ${GRUB_BADRAM}"
fi