opkg update
opkg install shadow-useradd shadow-userdel sudo shadow-su shadow-common shadow-groupadd shadow-groupdel shadow-groupmod shadow-groups shadow-utils
mkdir -p /home/[newuser]/.terminfo /home/[newuser]/.ssh
chown -R [newuser]:[newuser] /home/[newuser]
useradd -m -G wheel -s /bin/ash [newuser]
passwd [newuser]