The following procedure is almost the same as the previous one, except that it is more automated, because we provided the menuconfig.config file to be loaded into the "make menuconfig" to set all the compilation options correctly before launching the compilation.
This work is based on the work of @cyounkins who improved my settings to compile the OpenWRT 19.07 version so that it can also work on 21.02 and 22.03 versions, a big thank you to him for his help https://github.com/cyounkins/edgerouter-factory . On his git, you can find his menuconfig.txt file that is a text file with all the human readable instructions to manually set and unset all the right options to compile correctly this short receipt, while the menuconfig.config file I provide, based on his settings, can be directly loaded from make menuconfig load option, saving you the 5 minutes necessary to do it manually.
These things where done under a fresh new install of Xubuntu 20.04.2 :
Open a terminal.
Then type the following commands :
sudo apt-get update
sudo apt install build-essential clang flex g++ gawk gcc-multilib gettext git libncurses5-dev libssl-dev python3-distutils rsync unzip zlib1g-dev
git clone https://www.github.com/openwrt/openwrt -b openwrt-22.03
cd openwrt
./scripts/feeds update -a
./scripts/feeds install -a
make defconfig
wget "https://raw.githubusercontent.com/stman/OpenWRT-19.07.2-factory-tar-file-for-Ubiquiti-EdgeRouter-x/master/Version 22.03/menuconfig.config"
make menuconfig
Then use the arrow to move selection to Load in order to load the EdgeRouter X configuration file for the build OpenWRT-22.03 : Enter the filename menuconfig.config then select OK.
Now select the Save option and choose .config as save filename, click OK, then select Exit. Select Exit again to get out of the menuconfig utility, we are now ready to compile the whole source code by entering the following commands into the bash shell :
make download
make -jXXX
For the last command above please replace XXX by the number of processor cores your computer has. In my case, I used the command make -j8 because I have an 8 cores computer. If you ignore how many cores your microprocessor has, please just type make alone.
The compilation should take about 10 minutes with 8 cores. Once it is finished, enter the following bash commands :
cd ./bin/targets/ramips/mt7621
ls -al
And you should see the following files :
ThinkPad-T400:~/openwrt/bin/targets/ramips/mt7621$ ls -al
total 8908
drwxr-xr-x 3 fjouvin fjouvin 4096 nov. 19 18:00 .
drwxr-xr-x 3 fjouvin fjouvin 4096 nov. 19 15:47 ..
-rw-r--r-- 1 fjouvin fjouvin 1983 nov. 19 17:47 config.buildinfo
-rw-r--r-- 1 fjouvin fjouvin 288 nov. 19 17:47 feeds.buildinfo
-rw-r--r-- 1 fjouvin fjouvin 3010560 nov. 19 17:59 openwrt-ramips-mt7621-ubnt_edgerouter-x-initramfs-factory.tar
-rw-r--r-- 1 fjouvin fjouvin 3002053 nov. 19 17:59 openwrt-ramips-mt7621-ubnt_edgerouter-x-initramfs-kernel.bin
-rw-r--r-- 1 fjouvin fjouvin 1358 nov. 19 17:59 openwrt-ramips-mt7621-ubnt_edgerouter-x.manifest
-rw-r--r-- 1 fjouvin fjouvin 3073159 nov. 19 17:59 openwrt-ramips-mt7621-ubnt_edgerouter-x-squashfs-sysupgrade.bin
drwxr-xr-x 2 fjouvin fjouvin 4096 nov. 19 17:59 packages
-rw-r--r-- 1 fjouvin fjouvin 749 nov. 19 18:00 sha256sums
-rw-r--r-- 1 fjouvin fjouvin 18 nov. 19 17:47 version.buildinfo
As you can see, there is an openwrt-ramips-mt7621-ubnt-erx-initramfs-factory.tar that was generated. Use this file to update your router from EdgeOS with usual procedures.