Here is the detailed procedure to compile an equivalent operational "short receipt" Tar factory image as I have been doing in my previous post.
These things where done under Xubuntu 18.04.2 :
Open a terminal.
Then type the following commands (One of them related to feeds install is doubled because some errors happen on the first launch):
sudo apt-get update
sudo apt-get install subversion g++ zlib1g-dev build-essential git python python3 python3-distutils libncurses5-dev gawk gettext unzip file libssl-dev wget libelf-dev ecj fastjar java-propose-classpath libldap2-dev libcap-dev libidn2-dev liblzma-dev libjansson-dev libpam-dev
git clone https://www.github.com/openwrt/openwrt -b openwrt-19.07
./scripts/feeds update -a
./scripts/feeds install -a
./scripts/feeds install -a
Now, from the menuconfig main screen,
- Set Target System to : MediaTek Ralink MIPS
- Set Subtarget to : MT7621 based board
- Set Target Profile to : Ubiquiti EdgeRouter X
Then select Save and accept to save the configuration under the proposed default filename .config and then select Exit until you quit the menuconfig utility and are back to the terminal bash prompt.
From here, enter the following bash commands :
Go into Global Build Options submenu, and then :
- Set Strip unnecessary export from the kernel image to *
- Set Strip unnecessary functions from libraries to *
From this screen, enter the submenu Kernel build options and then :
- Unset Compile the kernel with debug filesystem enabled
- Unset Compile the kernel with symbol table information
- Unset Compile the kernel with debug information
Then select Exit until you back reach the menuconfig main screen, then select Save , it will propose you to save the configuration under the default filename .config , accept it, and then select Exit until you are back to the terminal bash prompt.
Back to the terminal bash prompt, enter the following commands :
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 :
And you should see the following files :
user@PC:~/openwrt/bin/targets/ramips/mt7621$ ls -al
drwxr-xr-x 3 user user 4096 mai 18 14:01 .
drwxr-xr-x 3 user user 4096 mai 18 13:55 ..
-rw-r--r-- 1 user user 335 mai 18 13:55 config.buildinfo
-rw-r--r-- 1 user user 263 mai 18 13:55 feeds.buildinfo
-rw-r--r-- 1 user user 1880 mai 18 14:01 openwrt-ramips-mt7621-device-ubnt-erx.manifest
-rw-r--r-- 1 user user 2938880 mai 18 14:01 openwrt-ramips-mt7621-ubnt-erx-initramfs-factory.tar
-rw-r--r-- 1 user user 2923299 mai 18 14:01 openwrt-ramips-mt7621-ubnt-erx-initramfs-kernel.bin
-rw-r--r-- 1 user user 2990868 mai 18 14:01 openwrt-ramips-mt7621-ubnt-erx-squashfs-sysupgrade.bin
drwxr-xr-x 2 user user 4096 mai 18 14:01 packages
-rw-r--r-- 1 user user 720 mai 18 14:01 sha256sums
-rw-r--r-- 1 user user 18 mai 18 13:55 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.
Then, update again the router under this temporary OpenWRT 19.07 built with the official stock sysupgrade 19.07.2 bin file from the OpenWRT website, and you're done.