My OpenWrt firmware image build guide

Build guide mainly based on an old revision of OpenWrt document "Quick Image Building Guide".

A suitable case-sensitive file system.
Last tested on WSL2 (Windows Version 10.0.19044.1586) with Debian GNU/Linux 11 (bullseye).

ver

cat /etc/os-release

Mind issue with path!

Debian terminal command:

sudo apt update

sudo apt update
sudo apt upgrade

sudo apt update && sudo apt upgrade

sudo apt autoremove

See examples of package installations.
Verify link and required packages!

Debian terminal command:

exit

If there is a new release in the branch, update local branch repository with Debian terminal command:

git pull

Debian terminal command:

./scripts/feeds update -a && ./scripts/feeds install -a

Debian terminal command:

make menuconfig

What about “make defconfig”?

For router hardware select corresponding values in menu ( link to router hardware table):

• “Target System” ⇒ “Select” ⇒ <target system> ⇒ “Select”
• “Subtarget” ⇒ “Select” ⇒ <subtarget> ⇒ “Select”
• “Target Profile” ⇒ “Select” ⇒ <target profile> ⇒ “Select”

Maybe add “LuCI”:

• “LuCI” ⇒ “Select” ⇒ “Collections” ⇒ “Select” ⇒ on “luci” press <Y> to include (= “*” built-in) ⇒ “Exit” ⇒ “Exit”
  

Maybe remove some packages to save space.
- remove “PPP daemon”:

• “Network” ⇒ “Select” ⇒ on “ppp” press <N> to exclude (= “ ” excluded) ⇒ “Exit”

- remove “IPv6 support”:

• “Global build settings” ⇒ “Select” ⇒ on “Enable IPv6 support in packages” press <N> to exclude (= “ ” excluded) ⇒ “Exit”
  

Maybe make WPA2 Enterprise with wpa_supplicant available by:
- remove “wpad-mini”:

- add “wpad”:

Maybe add load balancing/failover with multiple WAN interfaces.
- add “MAC-VLAN support”:

• “Kernel modules” ⇒ “Select” ⇒ “Network Devices” ⇒ “Select” ⇒ on “kmod-macvlan” press <Y> to include (= “*” built-in) ⇒ “Exit” ⇒ “Exit”

- add “LuCI support for the MWAN3 multiwan hotplug script”:

• “LuCI” ⇒ “Select” ⇒ “3. Applications” ⇒ “Select” ⇒ on “luci-app-mwan3” press <Y> to include (= “*” built-in) ⇒ “Exit” ⇒ “Exit”

- or without LuCI, add “Multiwan hotplug script with connection tracking support”:

• “Network” ⇒ “Select” ⇒ “Routing and Redirection” ⇒ “Select” ⇒ on “mwan3” press <Y> to include (= “*” built-in) ⇒ “Exit” ⇒ “Exit”
  

Maybe add network watchdog utility.
- add “LuCI Support for Watchcat”:

• “LuCI” ⇒ “Select” ⇒ “3. Applications” ⇒ “Select” ⇒ on “luci-app-watchcat” press <Y> to include (= “*” built-in) ⇒ “Exit” ⇒ “Exit”

- or without LuCI, add “Watchcat”:

• “Utilities” ⇒ “Select” ⇒ on “Watchcat” press <Y> to include (= “*” built-in) ⇒ “Exit”

To exit OpenWrt Configuration and save target with options settings do following:

• “Exit” ⇒ “Yes”

Debian terminal command:

make V=s 2>&1 | tee build.log

Completion can take time. If successful, the images are in the directory ./bin/targets/<target directory>

• The *-factory.bin image file is for the first installation of OpenWrt on the target.
• The *-sysupgrade.bin image file is for updating an existing OpenWrt installation.

To recompile the images, remove files from directory ./bin/targets/<target directory> and build image (step 4) again.
What about cleaning up “make clean”, “make dirclean”, “make distclean”?

For faster compiling, use make -j N, where N is the number of CPU cores + 1. Be aware that this method is prone to errors during compiling. In case you encounter compile errors, your very first step is to compile again without -j N. Use of make download prior to parallel compilation is recommended to prevent some of these errors (-jN is generally safe for the download step for those with faster Internet connectivity.)

To build an OpenWrt firmware image for other hardware or with other options, use the OpenWrt Configuration (step 3) and then build image (step 4) again.

Also more hardware info on wikidevi.

Other OpenWrt pages:

• Developer guide
• Beginners guide to building your own firmware