Comment 3 for bug 85014

Oops... the above is not a good one, should be [0-9], however, if selinux=0 is assigned in bootparam, upstart will go wrong.
Therefore maybe make it like:
------
start on rcS/stop

script
        runlevel --reboot || true

        if grep -q -w -- "-s\|single\|S" /proc/cmdline; then
            telinit S
        elif grep -qE -- "[[:space:]]+[0-9][[:space:]]+" /proc/cmdline; then
            RL="$(grep -Eo -- "[[:space:]]+[0-9][[:space:]]+" /proc/cmdline)"
            if [ -n "$RL" ]; then
                telinit $RL
            else
                telinit 2
            fi
        elif [ -r /etc/inittab ]; then
            RL="$(sed -n -e "/^id:[0-9]*:initdefault:/{s/^id://;s/:.*//;p}" /etc
/inittab || true)"
            if [ -n "$RL" ]; then
                telinit $RL
            else
                telinit 2
            fi
        else
            telinit 2
        fi
end script
-------------
I bet you have better solution about this.