Based on Marvel Kirkwood mv6282 boostrap.xsh.
Modified CPU checking instruction for DS213J (Marvel Armada-370).
root login into DS213J
$ /usr/syno/bin/wget https://github.com/hsleep/ds213j_bootstrap/raw/master/syno-mvam-bootstrap_1.2-7_arm_ds213j.xsh --no-check-certificate
$ sh syno-mvam-bootstrap_1.2-7_arm_ds213j.xsh