Hi
if ssh(dropbear) not work, check /etc/dropbear/*
if there is nothing in /etc/dropbear, it need generate key
use these two command to generate key
dropbearkey -t dss -f /etc/dropbear/dropbear_rsa_host_key
dropbearkey -t rsa -f /etc/dropbear/dropbear_dss_host_key