#! /bin/sh -e

# Make GRUB rescue image
# Copyright (C) 1999,2000,2001,2002,2003,2004,2005,2006,2007,2008,2009  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/>.

# Initialize some variables.
transform="@program_transform_name@"

prefix=@prefix@
exec_prefix=@exec_prefix@
bindir=@bindir@
libdir=@libdir@
PACKAGE_NAME=@PACKAGE_NAME@
PACKAGE_TARNAME=@PACKAGE_TARNAME@
PACKAGE_VERSION=@PACKAGE_VERSION@
target_cpu=@target_cpu@
platform=@platform@
pkglibdir=${libdir}/`echo ${PACKAGE_TARNAME}/${target_cpu}-${platform} | sed ${transform}`

grub_mkimage=${bindir}/`echo grub-mkelfimage | sed ${transform}`
grub_mkisofs=${bindir}/`echo grub-mkisofs | sed ${transform}`

# Usage: usage
# Print the usage.
usage () {
    cat <<EOF
Usage: $0 [OPTION] output_image
Make GRUB rescue image.

  -h, --help              print this message and exit
  -v, --version           print the version information and exit
  --modules=MODULES       pre-load specified modules MODULES
  --overlay=DIR           overlay directory DIR in the memdisk image
                          (may be specified multiple times)
  --pkglibdir=DIR         use images from directory DIR instead of ${pkglibdir}
  --grub-mkimage=FILE     use FILE as grub-mkimage
  --grub-mkisofs=FILE     use FILE as grub-mkisofs

$0 generates a bootable rescue image.

Report bugs to <bug-grub@gnu.org>.
EOF
}

input_dir=${pkglibdir}

# Check the arguments.
for option in "$@"; do
    case "$option" in
    -h | --help)
	usage
	exit 0 ;;
    -v | --version)
	echo "$0 (GNU GRUB ${PACKAGE_VERSION})"
	exit 0 ;;
    --modules=*)
	modules=`echo "$option" | sed 's/--modules=//'` ;;
    --overlay=*)
	overlay=${overlay}${overlay:+ }`echo "$option" | sed 's/--overlay=//'` ;;
    --pkglibdir=*)
	input_dir=`echo "$option" | sed 's/--pkglibdir=//'` ;;
    --grub-mkimage=*)
	grub_mkimage=`echo "$option" | sed 's/--grub-mkimage=//'` ;;
    --grub-mkisofs=*)
	grub_mkisofs=`echo "$option" | sed 's/--grub-mkisofs=//'` ;;
    -*)
	echo "Unrecognized option \`$option'" 1>&2
	usage
	exit 1
	;;
    *)
	if test "x$output_image" != x; then
	    echo "Unrecognized option \`$option'" 1>&2
	    usage
	    exit 1
	fi
	output_image="${option}" ;;
    esac
done

if test "x$output_image" = x; then
  usage
  exit 1
fi

memdisk_dir=`mktemp -d`
iso9660_dir=`mktemp -d`
mkdir -p ${memdisk_dir}/boot/grub ${iso9660_dir}/boot/grub

for file in ${input_dir}/*.mod ${input_dir}/efiemu??.o \
  ${input_dir}/command.lst ${input_dir}/moddep.lst ${input_dir}/fs.lst \
  ${input_dir}/handler.lst ${input_dir}/parttool.lst; do
  if test -f "$file"; then
    cp -f "$file" ${iso9660_dir}/boot/grub/
  fi
done

# obtain date-based UUID
iso_uuid=$(date +%Y-%m-%d-%H-%M-%S-00)

# first-stage grub.cfg
cat << EOF >> ${memdisk_dir}/boot/grub/grub.cfg
search --fs-uuid --set ${iso_uuid}
set prefix=(\${root})/boot/grub
source /boot/grub/grub.cfg
EOF

# build memdisk
memdisk_img=`mktemp`
tar -C ${memdisk_dir} -cf ${memdisk_img} boot
rm -rf ${memdisk_dir}

# build core.img
mkdir -p ${iso9660_dir}/boot/grub
${grub_mkimage} -d ${input_dir}/ -m ${memdisk_img} -o ${iso9660_dir}/boot/multiboot.img \
  at_keyboard memdisk tar ata search iso9660 configfile sh
rm -f ${memdisk_img}

for d in ${overlay}; do
  echo "Overlaying $d"
  cp -dpR "${d}"/* "${iso9660_dir}"/
done

# second-stage grub.cfg
modules="`cat ${input_dir}/partmap.lst` ${modules}"
for i in ${modules} ; do
  echo "insmod $i"
done > ${iso9660_dir}/boot/grub/grub.cfg

# build iso image
${grub_mkisofs} \
  --modification-date=$(echo ${iso_uuid} | sed -e s/-//g) \
  -o ${output_image} -r -J ${iso9660_dir}

exit 0