We usually use Debian and Ubuntu but many other distributions should also work. It is also possible to build on OSX. Building firmware directly on a Windows platform is not supported. However, if all you have available is a windows machine then we would recommend to set up a linux based virtual machine. Note: the following build was made on Ubuntu 16.04.5 LTS running 4.15.0-43 kernel.

Once you have a Linux OS running install the following prerequisite packages (some are optional):

sudo apt-get update
sudo apt-get install git git-doc subversion build-essential flex wget gawk unzip man file python2.7 zlib1g-dev libssl-dev libncurses5-dev

Get latest sources from 8devices OpenWRT branch:

git clone --branch openwrt-19.07-ipq40xx-4.14 https://github.com/8devices/openwrt-8devices.git
cd openwrt-8devices

The easiest way is simply to execute a build script and wait until firmware will be built.

./build.sh

Building is a CPU heavy process and may take a long time depending on your CPU capabilities.

Once finished the compiled firmware image ending with jalapeno-squashfs-nand-factory.ubi will be placed under bin/targets/ipq40xx/generic directory.