How to Install the Latest OpenWRT on Arduino Yun

By the time I am writing this, this might be the first article that tells you how to install OpenWRT on Arduino Yun because no one talks about it.

Also, Arduino Yun is already reached its end of life, and the version history is not well documented in each article so I will write it as clearly as I can.

Here I am using the old Arduino Yun. It comes with the 1.1.4 version of the bootloader.

Now to update it to the latest OpenWRT what we will need to do is:

Update the bootloader to 1.1.5 because 1.1.4 does not support bigger kernel upload by default
Flash the firmware from the latest build of OpenWRT

Board Development History

The old version of Yun is able to use the latest OpenWRT. The 1.1.5 bootloader is also available for rev. 2 so I think the Yun rev. 2 is also able to boot the latest OpenWRT.

No need to be afraid of bricking, if you still have the bootloader, everything can be reflashed. Go here if you need to re-flashing the stock Yun firmware.

Prerequisites

Arduino Yun v1 (rev 2 is also compatible but not covered here)
Linux PC (Windows or Mac is also compatible but not covered here)
LAN and MicroUSB cable
Access Point with Internet Connection

Bootloader Mode

Connect Yun LAN and Micro USB to your PC.

Open Arduino IDE, and download the bridge library.

Select menu Sketch > Include Library > Manage Libraries ...

Search bridge on library manager and install

Open YunSerialTerminal sketch by selecting File > Example > Bridge > YunSerialTerminal

Upload YunSerialTerminal; open the serial monitor and set the baud rate to 115200.

Press enter

A terminal will show up:

Reset Yun by pressing a white button near LEDs.

Go to boot mode quickly, send lin (or depending on the message, some bootloaders need ard, some only needs to press any character) command into the serial monitor until the bootloader command prompt is shown below

Setting TFTP Server

Now let’s set up the host.

Make sure your PC IP connected to Yun is 192.168.1.2 with gateway 192.168.1.1.

You can use any IP here, but if you want to follow me just use the same IP as my configuration

Install tftp server

sudo apt-get install tftpd-hpa

In my Linux OS, after installing check the tftp folder

$ cat /etc/default/tftpd-hpa
# /etc/default/tftpd-hpa

TFTP_USERNAME="tftp"
TFTP_DIRECTORY="/srv/tftp"
TFTP_ADDRESS=":69"
TFTP_OPTIONS="--secure"

in my case it is /srv/tftp

Now download this Yun-Go-Updater, and extract the bootloader file only:

u-boot-arduino-lede.bin

And move it to the /srv/tftp directory

$ mv u-boot-arduino-lede.bin /srv/tftp

Then get the latest OpenWRT firmware here

By the time I am writing this, it is 22.03.3

Put the firmware also in tftp folder

openwrt-22.03.3-ath79-generic-arduino_yun-squashfs-sysupgrade.bin

So now the /srv/tftp contains our bootloader and OpenWRT firmware.

Flashing the Bootloader and OpenWRT Firmware

After everything is set up then send these commands in Yun serial monitor:

linino> setenv serverip 192.168.1.2;

linino> setenv ipaddr 192.168.1.1;

The Yun is set to 192.168.1.1 and our PC is 192.168.1.2

Send the bootloader to Yun

tftp 0x80060000 u-boot-arduino-lede.bin

Then erase the old bootloader and replace using these commands.

erase 0x9f000000 +0x40000;
cp.b $fileaddr 0x9f000000 $filesize;
erase 0x9f040000 +0x10000

Below is the output

Then we can send the OpenWRT firmware to Yun, erase the previous firmware, and write the OpenWRT

tftp 0x80060000 openwrt-22.03.3-ath79-generic-arduino_yun-squashfs-sysupgrade.bin;

erase 0x9f050000 +0xE50000;
cp.b $fileaddr 0x9f050000 $filesize;

Below is the output

Now reset by pressing the white Yun reset button near the LEDs.

Now we can see the new bootloader and working latest and the most bleeding edge OpenWRT

Press Enter again in the serial monitor to activate the console

Now we have the latest OpenWRT installed on Arduino Yun! 🙂

By default, the wifi is turned off. To access the Yun, run this command to set the Yun IP.

ifconfig eth0 192.168.1.1

Once the IP is set, you can access the OpenWRT web interface on the browser by visiting 192.168.1.1

Connect to your Wifi access point and run opkg update to update the package list.

Expand the Storage

There are so many packages that you can install but the Yun memory is too small. However, we can expand the storage using extroot method.

The previous storage expanding steps does not work on the newest OpenWRT. So to expand the storage using a microSD card, use the OpenWRT instruction. Here is the screenshot of the expanded storage size of my Arduino Yun.

Have Fun 🙂