Thank you for the hint! By the way, it looks like the first firmware that I uploaded via web interface is somehow working, upload via tftp doesn't change anything (probably it does not apply any new firmware from tftp without confirmation from serial console).
Anyway, I managed to configure it, but something is wrong with filesystem - says no space. What can be done in this situation?
root@OpenWrt:~# opkg update
Downloading http://downloads.openwrt.org/snapshots/ … ckages.gz.
Updated list of available packages in /var/opkg-lists/barrier_breaker.
root@OpenWrt:~# opkg install luci
Installing luci (svn-r10276-1) to root...
Collected errors:
* verify_pkg_installable: Only have 0kb available on filesystem /overlay, pkg luci needs 1
* opkg_install_cmd: Cannot install package luci.
root@OpenWrt:~# df
Filesystem 1K-blocks Used Available Use% Mounted on
tmpfs 14776 556 14220 4% /tmp
tmpfs 512 0 512 0% /dev
root@OpenWrt:~# mount
rootfs on / type rootfs (rw)
proc on /proc type proc (rw,noatime)
sysfs on /sys type sysfs (rw,noatime)
tmpfs on /tmp type tmpfs (rw,nosuid,nodev,noatime)
tmpfs on /dev type tmpfs (rw,relatime,size=512k,mode=755)
devpts on /dev/pts type devpts (rw,relatime,mode=600)
debugfs on /sys/kernel/debug type debugfs (rw,noatime)
root@OpenWrt:~#