#!/bin/bash
# mkinitcpio - modular tool for building an init ramfs cpio image
#
# IMPORTANT: We need to keep a common base syntax here because
# some of these hooks/scripts need to run under busybox's ash -
# therefore, the following constraints should be enforced:
#   variables should be quoted and bracketed "${SOMEVAR}"
#   inline execution should be done with $() instead of backticks
#   use -z "${var}" to test for nulls/empty strings
#   in case of embedded spaces, quote all path names and string comparisons
#

shopt -s extglob

# Settings
TMPDIR="$(mktemp -d /tmp/mkinitcpio.XXXXXX)"
BASEDIR=""
MESSAGEFILE="${TMPDIR}/message"
KERNELVERSION="$(uname -r)"
FUNCTIONS="functions"
CONFIG="mkinitcpio.conf"
HOOKDIR="hooks"
INSTDIR="install"
MODULE_FILE=""
SAVELIST=""
GENIMG=""
PRESET=""
MESSAGE=""
SKIPHOOKS=()
PRESETDIR="mkinitcpio.d"
QUIET="y"
SHOW_AUTOMODS="n"
COMPRESSION="gzip"
COMPRESSION_OPTIONS=""

if [ ! $UID ]; then
    UID=$(id -u)
fi

# Add /{,usr}/sbin to path
# works around undetected problems like in #8448
PATH="${PATH}:/sbin:/usr/sbin"
# Sanitize environment further
# GREP_OPTIONS="--color=always" will break everything
unset GREP_OPTIONS

APPNAME=${0##*/}

usage ()
{
    echo "${APPNAME}: usage"
    echo "  -c CONFIG        Use CONFIG file. default: /etc/mkinitcpio.conf"
    echo "  -k KERNELVERSION Use KERNELVERSION. default: $(uname -r)"
    echo "  -s               Save build directory. default: no"
    echo "  -b BASEDIR       Use BASEDIR. default: /"
    echo "  -g IMAGE         Generate a cpio image as IMAGE. default: no"
    echo "  -p PRESET        Build specified preset."
    echo "  -m MESSAGE       Print MESSAGE before passing control to init."
    echo "  -S SKIPHOOKS     Skip SKIPHOOKS (comma-separated) when building the image."
    echo "  -v               Verbose output. Default: no"
    echo "  -M               Display modules found via autodetection." 
    echo "  -L               List all available hooks." 
    echo "  -H HOOKNAME      Output help for hook 'HOOKNAME'."
    echo "  -h               This message."
    cleanup
    exit 1
}

cleanup ()
{
    if [[ $SAVELIST ]]; then
        echo ":: build directory saved in $TMPDIR"
    else
        rm -rf ${TMPDIR}
    fi
}

sighandler() {
    cleanup
    exit 1
}

get_kernver() {
    local kernel=$1

    if [[ "${kernel:0:1}" != / ]]; then
        echo $kernel
        return 0
    fi

    [[ -r "$kernel" ]] || return 1

    read _ kernver < <(file -b "$BASEDIR$kernel" | grep -o 'version [^ ]\+')
    if [[ "$kernver" && -e "$BASEDIR/lib/modules/$kernver" ]]; then
        echo "$kernver"
        return 0
    fi

    return 1
}

trap sighandler TERM INT

while getopts ':c:k:sb:g:p:m:vH:LMhS:' arg; do
    if [ "${OPTARG#-}" != "${OPTARG}" ]; then
        echo "error: optional argument to '-${arg}' begins with a '-'"
        echo "  you probably don't want this....aborting."
        usage
    fi
    case "${arg}" in
        c) CONFIG="${OPTARG}" ;;
        k) optkver=$OPTARG ;;
        s) SAVELIST="y"; ;;
        b) BASEDIR="${OPTARG}" ;;
        g) GENIMG="${OPTARG}" ;;
        p) PRESET="${OPTARG}" ;;
        m) MESSAGE="${OPTARG}" ;;
        v) QUIET="n" ;;
        S) OLDIFS=${IFS}
           IFS=,
           SKIPHOOKS=(${OPTARG})
           IFS=${OLDIFS}
           unset OLDIFS
           ;;
        H) . "${INSTDIR}/${OPTARG}";
           echo "Help for hook '${OPTARG}':"
           help
           cleanup
           exit 0 ;;
        L) echo "Available hooks: " 
           for h in ${INSTDIR}/*; do
               echo "   ${h##*/}"
           done
           cleanup
           exit 0 ;;
        M) SHOW_AUTOMODS="y" ;;
        h|?) usage ;;
        :) echo "${OPTARG} requires a value..."; usage ;;
        *) echo "invalid argument '${arg}'"; usage ;;
    esac
done
shift $((${OPTIND} - 1))

if [[ $optkver ]]; then
    if ! KERNELVERSION=$(get_kernver "$optkver"); then
         echo "error: '$optkver' is an invalid kernel specifier"
         cleanup
         exit 1
    fi
fi

# use preset $PRESET
if [[ $PRESET ]]; then
    if [[ -f "$PRESETDIR/$PRESET.preset" ]]; then
        # Use -b, -m and -v options specified earlier
        declare -a preset_mkopts preset_cmd
        [[ $BASEDIR ]] && preset_mkopts+=(-b "$BASEDIR")
        [[ $MESSAGE ]] && preset_mkopts+=(-m "$MESSAGE")
        [[ "$QUIET" = n ]] && preset_mkopts+=(-v)
        # Build all images
        . "$PRESETDIR/$PRESET.preset"
        for p in "${PRESETS[@]}"; do
            echo "==> Building image \"${p}\""
            preset_cmd=("${preset_mkopts[@]}")

            preset_kver=${p}_kver
            if [[ ${!preset_kver:-$ALL_kver} ]]; then
                preset_cmd+=(-k "${!preset_kver:-$ALL_kver}")
            else
                echo "==> No kernel version specified. Skipping image \"${p}\"."
                continue
            fi

            preset_config=${p}_config
            if [[ ${!preset_config:-$ALL_config} ]]; then
              preset_cmd+=(-c "${!preset_config:-$ALL_config}")
            else
                echo "==> No configuration file specified. Skipping image \"${p}\"."
                continue
            fi

            preset_image=${p}_image
            if [[ ${!preset_image} ]]; then
                preset_cmd+=(-g "${!preset_image}")
            else
                echo "==> No image file specified. Skipping image \"${p}\"."
                continue
            fi

            preset_options=${p}_options
            if [[ ${!preset_options} ]]; then
                preset_cmd+=(${!preset_options}) # intentional word splitting
            fi

            echo "==> Running command: $0 ${preset_cmd[@]}"
            if "$0" "${preset_cmd[@]}"; then
                echo "==> SUCCESS"
            else
                echo "==> FAIL"
            fi
        done
        cleanup
        exit 0
    else
        echo "Preset $PRESET does not exist. Exiting."
        cleanup
        exit 1
    fi
fi

# remove trailing / from BASEDIR
BASEDIR="${BASEDIR%/}"

MODULEDIR="${BASEDIR}/lib/modules/${KERNELVERSION}"

if [[ $GENIMG ]]; then
  IMGPATH=$(readlink -f "$GENIMG")
  if [[ -z $IMGPATH || ! -w ${IMGPATH%/*} ]]; then
    echo "error: unable to write to path: '$GENIMG'"
    cleanup
    exit 1
  fi
fi

if [ -n "${BASEDIR}" ]; then
    if [ "${BASEDIR}" = "${BASEDIR#/}" ]; then
        BASEDIR="$(pwd)/${BASEDIR}"
    elif [ ! -d "${BASEDIR}" ]; then
        echo "base directory '${BASEDIR}' does not exist or is not a directory"
        cleanup
        exit 1
    fi
fi

if [ ! -f "${CONFIG}" ]; then
    echo "config file '${CONFIG}' cannot be found, aborting..."
    cleanup
    exit 1
fi
. "${CONFIG}"

BASEDIR=${BASEDIR//+(\/)//}
MODULEDIR=${MODULEDIR//+(\/)//}

. "${FUNCTIONS}"

if [ "${SHOW_AUTOMODS}" = "y" ]; then
    echo "Modules autodetected:"
    . "${INSTDIR}/autodetect"
    build
    cat "${MODULE_FILE}"
    cleanup
    exit 0
fi

if [ -z "${GENIMG}" ]; then
    echo ":: Begin dry run"
else
    echo ":: Begin build"
fi
#parse 'global' hook, as defined in ${CONFIG}
parse_hook

for hook in ${HOOKS}; do
    in_array "$hook" "${SKIPHOOKS[@]}" && continue
    unset MODULES BINARIES FILES SCRIPT
    build () { msg "${hook}: no build function..."; }
    # Deprecation check
    # A hook is considered deprecated if it is a symlink
    # within $INSTDIR.
    if [ -h "${INSTDIR}/${hook}" ]; then
        newhook="$(readlink -ne "${INSTDIR}/${hook}")"
        if [ -n "${newhook}" -a "${INSTDIR}/$(get_basename ${newhook})" -ef "${newhook}" ]; then
            newhook="$(get_basename ${newhook})"
            echo "   -------------------------------------------------------------------"
            echo "   WARNING: Hook \"${hook}\" is deprecated."
            echo "            Replace it with \"${newhook}\" in your configuration file."
            echo "   -------------------------------------------------------------------"
            hook="${newhook}"
        fi
    fi
    if [[ -r "${INSTDIR}/${hook}" ]]; then
        . "${INSTDIR}/${hook}"
        echo ":: Parsing hook [${hook}]"
        if [[ $(type -t install) = 'function' ]]; then
            echo "  -----------------------------------------------------------------------"
            echo "  WARNING: Hook '$hook' uses a deprecated 'install' function. This "
            echo "           should be switched to a 'build' function instead."
            echo "  -----------------------------------------------------------------------"
            install
            unset install
        else
            build
        fi
        parse_hook
    else
        die "Hook '${hook}' can not be found."
    fi
done

if (( ${#ADDED_MODULES[*]} )); then
    echo ":: Generating module dependencies"
    /sbin/depmod -b "${TMPDIR}/root" "${KERNELVERSION}"
    rm "$TMPDIR/root/lib/modules/$KERNELVERSION"/modules.!(dep.bin|alias.bin|symbols.bin)
fi

declare -i status=0
declare -a pipesave
if [ -n "${GENIMG}" ]; then
    echo ":: Generating image '${GENIMG}'"
    [ ${COMPRESSION} = "xz" ] && COMPRESSION_OPTIONS="${COMPRESSION_OPTIONS} --check=crc32"

    pushd "$TMPDIR/root" >/dev/null
    find . -print0 | bsdcpio -0oH newc | $COMPRESSION $COMPRESSION_OPTIONS > "$IMGPATH"
    pipesave=("${PIPESTATUS[@]}") # save immediately
    popd >/dev/null

    if (( pipesave[0] )); then
        errmsg="find reported an error"
    elif (( pipesave[1] )); then
        errmsg="bsdcpio reported an error"
    elif (( pipesave[2] )); then
        errmsg="$COMPRESSION reported an error"
    fi

    if [[ $errmsg ]]; then
        echo ":: Image generation FAILED ($errmsg)"
        status=1
    else
        echo ":: Image generation successful"
    fi

else
    echo ":: Dry run complete, use -g IMAGE to generate a real image"
fi

cleanup

exit ${status}
#vim:set ft=sh ts=4 sw=4 noet: