flashing the mi mini wifi router with OpenWRT

I lost connection with the mi mini wifi router after following this procedure. I flashed u-boot to the bootloader, and it succeeded, but It would no longer boot the firmware.
Apparently it did boot into u-boot, but to find that out I had to get a serial console. Instead of getting a usb serial to TTL I tried using a raspberry pi and the GPIOpins. It worked.

opening the MI mini wifi

two screws hold i together, opening it from there was a bit harder. You have to forcefully get underneathe four little hooks at the bottom front of the device

after opening it, all we need is accessible.

soldering a serial port on it

I used an old connector I had lying around, easy t get to the breadboard

next step involves the RPi

you can then hook it up to the RPis Tx, Rx and GND pins. As both devices use 3v3 TTL, no extra circuitry is needed

ssh over to the RPi

once your logged in, type

$ minicom -b 115200 -o -D /dev/ttyAMA0

to start a serial console on the RPis GPIOports. Once it runs, boot the mi and you should see this

 

now the easy part

connect a UTP cable from a LAN port directly to your computer, and assign your PC a manual address in th 192.168.1.x but not 192.168.1.1

start the http server on the mi

MT7620 # httpd
raspi_read: from:40028 len:6
NetTxPacket = 0x83FB5080

KSEG1ADDR(NetTxPacket) = 0xA3FB5080
Trying Eth0 (10/100-M)

Waitting for RX_DMA_BUSY status Start… done
ETH_STATE_ACTIVE!!
HTTP server is starting at IP : 192.168.1.1
HTTP server is ready!

Keep going WEB failsafe, rx_counter=0 , GoGoGo!!!

point you browser to 192.168.1.1

and upload your firmware…

I flashed openwrt-ramips-mt7620-xiaomi-miwifi-mini-squashfs-sysupgrade.bin

connect to internet (cable)

and start setting up OpenWRT

$ opkg update && opkg list luci-*
$ opkg install luci-ssl

$ /etc/init.d/uhttpd start
$ /etc/init.d/uhttpd enable

$ uci set wireless.@wifi-device[0].disabled=0; uci commit wireless; wifi

 

make sure it boots from the flash partition

by default it waits for a tftp image to be transferred, so:

$ printenv

and take a look at the env variables

$ bootcmd=tftp

this should be

“bootcmd=bootm bc050000”

so set it and save it

$ setenv bootcmd bootm bc050000

$ saveenv

now reboot, test and go and configure it