GitHub - Baumgartl/openwrt-xiaomi-mir3: OpenWrt with support for the Xiaomi Mi WiFi Router 3 a/k/a MIR3. Based on current stable release v18.06.2 with Linux Kernel 4.14.95.
OpenWRT - Install X-WRT on Xiaomi Router 3 via TFTP - YouTube
GitHub - Degete/openwrt-conf-xiaomi-mi-r3: 📡 OpenWrt Firmware (X-WRT) for Xiaomi Mi Router 3
Unsuccessful atempt to install OpenWRT on Xiaomi Mi Router 4A 100M version : r/openwrt