Mini Shell

#!/bin/sh

type getarg >/dev/null 2>&1 || . /lib/dracut-lib.sh

[ -z "$root" ] && root=$(getarg root=)

# support legacy syntax of passing liveimg and then just the base root
if getargbool 0 rd.live.image -d -y liveimg; then
    liveroot="live:$root"
fi

if [ "${root%%:*}" = "live" ] ; then
    liveroot=$root
fi

[ "${liveroot%%:*}" = "live" ] || exit 0

case "$liveroot" in
    live:LABEL=*|LABEL=*) \
        root="${root#live:}"
        root="${root//\//\\x2f}"
        root="live:/dev/disk/by-label/${root#LABEL=}"
        rootok=1 ;;
    live:CDLABEL=*|CDLABEL=*) \
        root="${root#live:}"
        root="${root//\//\\x2f}"
        root="live:/dev/disk/by-label/${root#CDLABEL=}"
        rootok=1 ;;
    live:UUID=*|UUID=*) \
        root="${root#live:}"
        root="live:/dev/disk/by-uuid/${root#UUID=}"
        rootok=1 ;;
    live:PARTUUID=*|PARTUUID=*) \
        root="${root#live:}"
        root="live:/dev/disk/by-partuuid/${root#PARTUUID=}"
        rootok=1 ;;
    live:PARTLABEL=*|PARTLABEL=*) \
        root="${root#live:}"
        root="live:/dev/disk/by-partlabel/${root#PARTLABEL=}"
        rootok=1 ;;
    live:/*.[Ii][Ss][Oo]|/*.[Ii][Ss][Oo])
        root="${root#live:}"
        root="liveiso:${root}"
        rootok=1 ;;
    live:/dev/*)
        rootok=1 ;;
    live:/*.[Ii][Mm][Gg]|/*.[Ii][Mm][Gg])
        [ -f "${root#live:}" ] && rootok=1 ;;
esac

[ "$rootok" != "1" ] && exit 0

GENERATOR_DIR="$2"
[ -z "$GENERATOR_DIR" ] && exit 1
[ -d "$GENERATOR_DIR" ] || mkdir "$GENERATOR_DIR"

getargbool 0 rd.live.overlay.readonly -d -y readonly_overlay && readonly_overlay="--readonly" || readonly_overlay=""
getargbool 0 rd.live.overlay.overlayfs && overlayfs="yes"
[ -e /xor_overlayfs ] && xor_overlayfs="yes"
[ -e /xor_readonly ] && xor_readonly="--readonly"
ROOTFLAGS="$(getarg rootflags)"
{
    echo "[Unit]"
    echo "Before=initrd-root-fs.target"
    echo "[Mount]"
    echo "Where=/sysroot"
    if [ "$overlayfs$xor_overlayfs" = "yes" ]; then
        echo "What=LiveOS_rootfs"
        if [ "$readonly_overlay$xor_readonly" = "--readonly" ]; then
            ovlfs=lowerdir=/run/overlayfs-r:/run/rootfsbase
        else
            ovlfs=lowerdir=/run/rootfsbase
        fi
        echo "Options=${ROOTFLAGS},${ovlfs},upperdir=/run/overlayfs,workdir=/run/ovlwork"
        echo "Type=overlay"
        _dev=LiveOS_rootfs
    else
        echo "What=/dev/mapper/live-rw"
        [ -n "$ROOTFLAGS" ] && echo "Options=${ROOTFLAGS}"
        _dev=$'dev-mapper-live\\x2drw'
    fi
} > "$GENERATOR_DIR"/sysroot.mount

mkdir -p "$GENERATOR_DIR/$_dev.device.d"
{
    echo "[Unit]"
    echo "JobTimeoutSec=3000"
    echo "JobRunningTimeoutSec=3000"
} > "$GENERATOR_DIR/$_dev.device.d/timeout.conf"