With Huawei E3272 + 1 WiFi connection
Uptime: ~4 hours with 3 connected clients.
Apply factory image via http web-gui or JBOOT recovery page
Upgrade may hang, at least then WebUI used.
Workaround: stop unbound and dnsmasq before upload f/w to release memory.
Happen then internal switch exist and disabled.
NETDEV WATCHDOG: eth0 (mtk_soc_eth): transmit queue 0 timed out
Workaround: unplug net cable untill device started
Workaround: remove switch from existing configuration or build f/w without defined switch in 02_network and reset config on/after update
If http doesn't work, it can be done with curl command:
curl -F FN=@XXXXX.bin http://192.168.123.254/upg
where XXXXX.bin is name of firmware file.