#!/bin/sh
# 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
# the klibc shell or even busybox's ash - therefore, the
# following constraints should be enforced:
#   variables should be quoted and bracketed "${SOMEVAR}"
#   inline execution should be done with $() instead of backticks
#   use "x${var}" = "x" to test for nulls/empty strings
#   incase of embedded spaces, quote all path names and string comaprissons
#
# TODO
#  sudo cp img /boot

HOOKDIR="hooks"

# Settings
BASEDIR=""
KERNELVERSION="$(uname -r)"
CONFIG="mkinitcpio.conf"
SAVELIST=""
GENIMG=""
APPEND=""

usage ()
{
    echo "TODO usage..."
    exit 1
}

while getopts 'c:k:sb:g:a' arg; do
    case "$arg" in
        c) CONFIG="$OPTARG" ;;
        k) KERNELVERSION="$OPTARG" ;;
        s) SAVELIST="y" ;;
        b) BASEDIR="$OPTARG" ;;
        g) GENIMG="$OPTARG" ;;
        a) APPEND="y" ;;
        ?) usage ;;
        *) echo "invalid argument '$arg'"; usage ;;
    esac
done
shift $(($OPTIND - 1))

# append a trailing / if needed
if [ "${BASEDIR:${#BASEDIR}}" == "/" ]; then
    BASEDIR="${BASEDIR:0:${#BASEDIR}-1}"
fi

MODULEDIR="${BASEDIR}/lib/modules/${KERNELVERSION}"
FILELIST=${1:-"initcpio.filelist"}

if [ "x${BASEDIR}" != "x" ]; then
    if [ "${BASEDIR:0:1}" != "/" ]; then
        echo "base directory '${BASEDIR}' must be an absolute path"
        exit 1
    elif [ ! -d "${BASEDIR}" ]; then
        echo "base directory '${BASEDIR}' does not exist or is not a directory"
        exit 1
    fi
fi

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

if [ -f "${FILELIST}" -a "x${APPEND}" == "x" ]; then
    echo "destination file list '${FILELIST}' exists - remove before running"
    exit 1
elif [ -f "${DESTIMG}" ]; then
    echo "destination image '${DESTIMG}' exists - remove before running"
    exit 1
else
    touch "${FILELIST}"
fi

# this function is a helper for the *-auto install functions
auto_modules ()
{
    aliases=$(find /sys/devices/ -name modalias -exec cat {} \;)
    modprobe --show-depends -a $aliases 2>/dev/null |\
        sed "s|insmod \(.*\)|\1|" | sort -u
}

add_dir()
{
    local dir
    dir="${1}"
    if [ "x${dir}" != "x" -a "${dir}" != "/" ]; then
        dir="${dir}" #this got stripped off above... put it back

        if ! grep "dir ${dir} " "${FILELIST}" 2>&1 > /dev/null; then
            add_dir $(dirname ${dir})
            echo "  adding dir ${dir}"
            echo "dir ${dir} 755 0 0" >> "${FILELIST}"
        fi
    fi
}

add_symlink ()
{
    local fil dest dir
    if [ -L ${1} ]; then
        fil="${1}"
        dest="${fil##$BASEDIR}"
        dir=$(dirname "${dest}")
        add_dir "${dir}"
        if ! grep "slink ${fil} " "${FILELIST}" 2>&1 > /dev/null; then
            echo "  adding symlink ${dest}"
            echo "slink ${dest} ${fil} $(stat -c '%a %u %g' ${fil})" >> "${FILELIST}"
        fi
    fi
}

add_file ()
{
    local fil lnk dir dest
    if [ -e "${1}" ]; then
        fil="${1}"
        lnk=$(readlink -f "${fil}")
        if [ -n "${lnk}" ]; then
            add_symlink "${fil}"
            fil="${lnk}"
        fi
        if [ $# -eq 2 ]; then
            dest="${2}"
        else
            dest="${fil##$BASEDIR}"
        fi

        dir=$(dirname "${dest}")
        add_dir "${dir}"

        if ! grep "file ${fil} " "${FILELIST}" 2>&1 > /dev/null; then
            echo "  adding file ${dest}"
            echo "file ${dest} ${fil} $(stat -c '%a %u %g' ${fil})" >> "${FILELIST}"
        fi
    fi
}

HAS_MODULES="n"
add_module()
{
    local fil path mod deps
    #cleanup - remove .ko, replace - and _ with [-_] to match either
    fil=$(basename "${1}" | sed -e "s|[-_]|\[-_\]|g" -e "s|\.ko$||g")

    for path in $(find "${MODULEDIR}" -type f -name "${fil}.ko"); do
        for mod in $(modinfo -F depends "${path}" | tr ',' ' '); do
            if [ "x${mod}" != "x" ]; then
                add_module "${mod}"
                HAS_MODULES="y"
            fi
        done
        add_file "${path}"
    done
}

add_binary()
{
    local bin type lib
    bin=$(which "${1}")
    if [ $? -ne 0 ]; then
        bin="${1}"
    fi

    if [ ! -f "${bin}" ]; then
        echo "add_binary: '${bin}' is not a file"
        return 1
    fi

    if [ $? -eq 0 ]; then
        type=$(file -b "${bin}")
        case "${type}" in
            *script*)
            msg "   adding '${type}' script, ensure proper interp exists..."
            add_file "${bin}"
            ;;
            *executable*)
            add_file "${bin}"
            #note, this will also handle 'not a dynamic executable' spit out by
            # static binaries... the deps will produce nothing
            for lib in $(ldd ${bin} 2>/dev/null | sed "s|.*=>\(.*\)|\1|"); do
                if [ "x${lib}" != "x" ]; then
                    #remove TLS libraries
                    notls=$(echo ${lib} | sed 's|/lib/tls.*/\(lib.*\)|/lib/\1|')
                    [ -e "${notls}" ] && lib="${notls}"
                    [ -f "${lib}" ] && add_file "${lib}"
                fi
            done
            ;;
            *)
            echo "add_binary: unknown type '${type}' for binary '${bin}'"
            return 1
            ;;
        esac
    fi
}

function parse_hook()
{
    local mod bin fil
    for mod in $MODULES; do
        if [ "x${mod}" != "x" ]; then
            add_module "${mod}"
        fi
    done

    for bin in $BINARIES; do
        if [ "x${bin}" != "x" ]; then
            add_binary "${bin}"
        fi
    done

    for fil in $FILES; do
        if [ "x${fil}" != "x" ]; then
            add_file "${fil}"
        fi
    done
}

#parse 'global' hook, as defined in ${CONFIG}
parse_hook

for hook in $HOOKS; do
    unset MODULES
    unset BINARIES
    unset FILES
    install () { msg "$hook: no install function..."; }
    source "${HOOKDIR}/${hook}"
    install
    parse_hook
    #quick test to check for existance... need a better way...
    if grep "run_hook" "${HOOKDIR}/${hook}" 2>&1>/dev/null; then
        add_file "${HOOKDIR}/${hook}" "/hooks/${hook}"
    fi
done

if [ "${HAS_MODULES}" == "y" ]; then
    add_file "${MODULEDIR}/modules.dep"
    add_file "${MODULEDIR}/modules.alias"
    add_file "${MODULEDIR}/modules.symbols"
fi

if [ "x$GENIMG" != "x" ]; then
    gen_init_cpio ${FILELIST} | gzip -9 > "${GENIMG}"
    if [ "x${SAVELIST}" == "x" ]; then
        rm ${FILELIST}
    fi
fi