#! /bin/sh
#
# Set a default boot entry for GRUB.
# Copyright (C) 2004,2009  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/>.

#set -eu

# Initialize some variables.
prefix=/usr
exec_prefix=/usr
sbindir=/usr/sbin
bindir=/usr/bin
sysconfdir="/etc"
PACKAGE_NAME=GRUB
PACKAGE_VERSION=2.03
datarootdir="/usr/share"
datadir="/usr/share"
if [ ! -v pkgdatadir ]; then
    pkgdatadir="${datadir}/grub"
fi

self=`basename $0`

grub_get_kernel_settings="${sbindir}/grub2-get-kernel-settings"
grub_editenv=${bindir}/grub2-editenv
etcdefaultgrub=/etc/default/grub

eval "$("${grub_get_kernel_settings}")" || true

EFIDIR=$(grep ^ID= /etc/os-release | sed -e 's/^ID=//' -e 's/rhel/redhat/' -e 's/\"//g')
if [ -d /sys/firmware/efi/efivars/ ]; then
    startlink=/etc/grub2-efi.cfg
    grubdir=`echo "/boot/efi/EFI/${EFIDIR}/" | sed 's,//*,/,g'`
else
    startlink=/etc/grub2.cfg
    grubdir=`echo "/boot/grub2" | sed 's,//*,/,g'`
fi

blsdir=`echo "/boot/loader/entries" | sed 's,//*,/,g'`

backupsuffix=.bak

arch="$(uname -m)"

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

. "${pkgdatadir}/grub-mkconfig_lib"

# Usage: usage
# Print the usage.
usage () {
    gettext_printf "Usage: %s\n" "$self"
    gettext "Switch to BLS config files.\n"; echo
    echo
    print_option_help "-h, --help" "$(gettext "print this message and exit")"
    print_option_help "-V, --version" "$(gettext "print the version information and exit")"
    echo
    print_option_help "--backup-suffix=$(gettext "SUFFIX")" "$backupsuffix"
    print_option_help "--bls-directory=$(gettext "DIR")" "$blsdir"
    print_option_help "--config-file=$(gettext "FILE")" "$startlink"
    print_option_help "--grub-defaults=$(gettext "FILE")" "$etcdefaultgrub"
    print_option_help "--grub-directory=$(gettext "DIR")" "$grubdir"
    # echo
    # gettext "Report bugs to <bug-grub@gnu.org>."; echo
}

argument () {
    opt=$1
    shift

    if test $# -eq 0; then
        gettext_printf "%s: option requires an argument -- \`%s'\n" "$self" "$opt" 1>&2
        exit 1
    fi
    echo $1
}

# Check the arguments.
while test $# -gt 0
do
    option=$1
    shift

    case "$option" in
    -h | --help)
        usage
        exit 0 ;;
    -V | --version)
        echo "$self (${PACKAGE_NAME}) ${PACKAGE_VERSION}"
        exit 0 ;;

    --backup-suffix)
        backupsuffix=`argument $option "$@"`
        shift
        ;;
    --backup-suffix=*)
        backupsuffix=`echo "$option" | sed 's/--backup-suffix=//'`
        ;;

    --bls-directory)
        blsdir=`argument $option "$@"`
        shift
        ;;
    --bls-directory=*)
        blsdir=`echo "$option" | sed 's/--bls-directory=//'`
        ;;

    --config-file)
        startlink=`argument $option "$@"`
        shift
        ;;
    --config-file=*)
        startlink=`echo "$option" | sed 's/--config-file=//'`
        ;;

    --grub-defaults)
        etcdefaultgrub=`argument $option "$@"`
        shift
        ;;
    --grub-defaults=*)
        etcdefaultgrub=`echo "$option" | sed 's/--grub-defaults=//'`
        ;;

    --grub-directory)
        grubdir=`argument $option "$@"`
        shift
        ;;
    --grub-directory=*)
        grubdir=`echo "$option" | sed 's/--grub-directory=//'`
        ;;

    *)
        gettext_printf "Unrecognized option \`%s'\n" "$option" 1>&2
        usage
        exit 1
        ;;
    esac
done

find_grub_cfg() {
    local candidate=""
    while [ -e "${candidate}" -o $# -gt 0 ]
    do
        if [ ! -e "${candidate}" ] ; then
            candidate="$1"
            shift
        fi

        if [ -L "${candidate}" ]; then
            candidate="$(realpath "${candidate}")"
        fi

        if [ -f "${candidate}" ]; then
            export GRUB_CONFIG_FILE="${candidate}"
            return 0
        fi
    done
    return 1
}

if ! find_grub_cfg ${startlink} ${grubdir}/grub.cfg ; then
  gettext_printf "Couldn't find config file\n" 1>&2
  exit 1
fi

if [ ! -d "${blsdir}" ]; then
    install -m 700 -d "${blsdir}"
fi

if [ -f /etc/machine-id ]; then
    MACHINE_ID=$(cat /etc/machine-id)
else
    MACHINE_ID=$(dmesg | sha256sum)
fi

mkbls() {
    local kernelver=$1 && shift
    local datetime=$1 && shift
    local bootprefix=$1 && shift

    local debugname=""
    local debugid=""
    local flavor=""

    if [ "$kernelver" == *\+* ] ; then
        local flavor=-"${kernelver##*+}"
        if [ "${flavor}" == "-debug" ]; then
            local debugname=" with debugging"
            local debugid="-debug"
        fi
    fi
    (
        source /etc/os-release

        cat <<EOF
title ${NAME} (${kernelver}) ${VERSION}${debugname}
version ${kernelver}${debugid}
linux ${bootprefix}/vmlinuz-${kernelver}
initrd ${bootprefix}/initramfs-${kernelver}.img
options \$kernelopts
id ${ID}-${datetime}-${kernelver}
grub_users \$grub_users
grub_arg --unrestricted
grub_class kernel${flavor}
EOF
    ) | cat
}

copy_bls() {
    for kernelver in $(cd /lib/modules/ ; ls -1) "" ; do
	bls_target="${blsdir}/${MACHINE_ID}-${kernelver}.conf"
	linux="/vmlinuz-${kernelver}"
	linux_path="/boot${linux}"
	kernel_dir="/lib/modules/${kernelver}"

	if [ ! -d "${kernel_dir}" ] ; then
            continue
	fi
	if [ ! -f "${linux_path}" ]; then
            continue
	fi

	linux_relpath="$("${grub_mkrelpath}" "${linux_path}")"
	bootprefix="${linux_relpath%%"${linux}"}"

	if [ -f "${kernel_dir}/bls.conf" ] ; then
            cp -af "${kernel_dir}/bls.conf" "${bls_target}"
            if [ -n "${bootprefix}" ]; then
		sed -i -e "s,^\(linux[^ \t]*[ \t]\+\).*,\1${bootprefix}${linux},g" "${bls_target}"
		sed -i -e "/^initrd/ s,\([ \t]\+\)\([^ \t]\+\),\1${bootprefix}\2,g" "${bls_target}"
            fi
	else
            mkbls "${kernelver}" \
		  "$(date -u +%Y%m%d%H%M%S -d "$(stat -c '%y' "${kernel_dir}")")" \
		  "${bootprefix}" \
		  >"${bls_target}"
	fi

	if [ "x$GRUB_LINUX_MAKE_DEBUG" = "xtrue" ]; then
            bls_debug="$(echo ${bls_target} | sed -e "s/${kernelver}/${kernelver}~debug/")"
            cp -aT  "${bls_target}" "${bls_debug}"
            title="$(grep '^title[ \t]' "${bls_debug}" | sed -e 's/^title[ \t]*//')"
            blsid="$(grep '^id[ \t]' "${bls_debug}" | sed -e "s/\.${ARCH}/-debug.${arch}/")"
            sed -i -e "s/^title.*/title ${title}${GRUB_LINUX_DEBUG_TITLE_POSTFIX}/" "${bls_debug}"
            sed -i -e "s/^id.*/${blsid}/" "${bls_debug}"
            sed -i -e "s/^options.*/options \$kernelopts ${GRUB_CMDLINE_LINUX_DEBUG}/" "${bls_debug}"
	fi
    done

    if [ -f "/boot/vmlinuz-0-rescue-${MACHINE_ID}" ]; then
	mkbls "0-rescue-${MACHINE_ID}" "0" "${bootprefix}" >"${blsdir}/${MACHINE_ID}-0-rescue.conf"
    fi
}

GENERATE=0
if grep '^GRUB_ENABLE_BLSCFG=.*' "${etcdefaultgrub}" \
        | grep -vq '^GRUB_ENABLE_BLSCFG="*true"*\s*$' ; then
    if ! sed -i"${backupsuffix}" \
            -e 's,^GRUB_ENABLE_BLSCFG=.*,GRUB_ENABLE_BLSCFG=true,' \
            "${etcdefaultgrub}" ; then
        gettext_printf "Updating %s failed\n" "${etcdefaultgrub}"
        exit 1
    fi
    GENERATE=1
elif ! grep -q '^GRUB_ENABLE_BLSCFG=.*' "${etcdefaultgrub}" ; then
    # prepend in case admins have been bad at newlines
    sed -i '1iGRUB_ENABLE_BLSCFG=true' "${etcdefaultgrub}"
    if ! grep -q '^GRUB_ENABLE_BLSCFG=true' "${etcdefaultgrub}" ; then
        gettext_printf "Updating %s failed\n" "${etcdefaultgrub}"
        exit 1
    fi
    GENERATE=1
fi

if [ "${GENERATE}" -eq 1 ] ; then
    copy_bls

    if [ $arch = "x86_64" ] && [ ! -d /sys/firmware/efi ]; then
	if ! cp ${prefix}/lib/grub//i386-pc/blscfg.mod ${grubdir}/i386-pc/ ; then
	    exit 1
	fi
    elif [ $arch = "ppc64" -o $arch = "ppc64le" ] && [ ! -d /sys/firmware/opal ]; then
	if ! cp ${prefix}/lib/grub/powerpc-ieee1275/blscfg.mod ${grubdir}/powerpc-ieee1275/ ; then
	    exit 1
	fi
    fi

    cp -af "${GRUB_CONFIG_FILE}" "${GRUB_CONFIG_FILE}${backupsuffix}"
    if ! grub2-mkconfig -o "${GRUB_CONFIG_FILE}" ; then
        cp -af "${GRUB_CONFIG_FILE}${backupsuffix}" "${GRUB_CONFIG_FILE}"
        sed -i"${backupsuffix}" \
            -e 's,^GRUB_ENABLE_BLSCFG=.*,GRUB_ENABLE_BLSCFG=false,' \
            "${etcdefaultgrub}"
        gettext_printf "Updating %s failed\n" "${GRUB_CONFIG_FILE}"
        exit 1
    fi
fi

# Bye.
exit 0