If I understand correctly JNR1010v2, WNR614v1, WNR618v1, WNR2020v1, JWNR2000v5, JWNR2010v5 routers use the same firmware.
Good news: some days ago support for JWNR2010v5 was added.
Bad news: because of 4/32 Warnig (as @slh said) official binary firmware image will never be released. You have to build it yourself.
Or ask author of port in topic