#! /bin/sh
set -e

# Copyright (C) 2010  Free Software Foundation, Inc.
# Copyright (C) 2014  CoreOS, 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/>.

parted=parted
grubshell=@builddir@/grub-shell

. "@builddir@/grub-core/modinfo.sh"

case "${grub_modinfo_target_cpu}-${grub_modinfo_platform}" in
    mips-qemu_mips | mipsel-qemu_mips | i386-qemu | i386-multiboot | i386-coreboot | mipsel-loongson)
	disk=ata0
	;;
    powerpc-ieee1275)
	disk=ieee1275//pci@80000000/mac-io@4/ata-3@20000/disk@0
	# FIXME: QEMU firmware has bugs which prevent it from accessing hard disk w/o recognised label.
	exit 0
	;;
    sparc64-ieee1275)
	disk=ieee1275//pci@1fe\,0/pci-ata@5/ide0@500/disk@0
	# FIXME: QEMU firmware has bugs which prevent it from accessing hard disk w/o recognised label.
	exit 0
	;;
    i386-ieee1275)
	disk=ieee1275/d
	# FIXME: QEMU firmware has bugs which prevent it from accessing hard disk w/o recognised label.
	exit 0
	;;
    mips-arc)
	# FIXME: ARC firmware has bugs which prevent it from accessing hard disk w/o dvh disklabel.
	exit 0 ;;
    mipsel-arc)
	disk=arc/scsi0/disk0/rdisk0
	;;
    *)
	disk=hd0
	;;
esac
img1="`mktemp "${TMPDIR:-/tmp}/tmp.XXXXXXXXXX"`" || exit 1
img2="`mktemp "${TMPDIR:-/tmp}/tmp.XXXXXXXXXX"`" || exit 1
trap "rm -f '${img1}' '${img2}'" EXIT

create_disk_image () {
    size=$1
    rm -f "${img1}"
    dd if=/dev/zero of="${img1}" bs=512 count=1 seek=$((size - 1)) status=none
    ${parted} -a none -s "${img1}" mklabel gpt
    cp "${img1}" "${img2}"
}

wipe_disk_area () {
    sector=$1
    size=$2
    dd if=/dev/zero of="${img2}" bs=512 count=${size} seek=${sector} conv=notrunc status=none
}

do_repair () {
    output="`echo "gptrepair ($disk)" | "${grubshell}" --disk="${img2}"`"
    if echo "${output}" | grep ^error; then
        return 1
    fi
    if echo "${output}" | grep -v GPT; then
        echo "Unexpected output ${output}"
        return 1
    fi
    echo "${output}"
}

echo "Nothing to repair:"
create_disk_image 100
do_repair
cmp "${img1}" "${img2}"
echo

echo "Repair primary (MBR left intact)"
create_disk_image 100
wipe_disk_area 1 1
do_repair
cmp "${img1}" "${img2}"
echo

echo "Repair backup"
create_disk_image 100
wipe_disk_area 99 1
do_repair
cmp "${img1}" "${img2}"
echo