Buildroot is a simple, efficient and easy-to-use tool to generate embedded Linux systems through cross-compilation. It includes a cross-compilation toolchain, root filesystem generation, kernel image compilation and bootloader compilation. Thanks to its kernel-like menuconfig, gconfig and xconfig configuration interfaces, building a basic system with Buildroot is easy and typically takes 15-30 minutes. The X.org stack, Gtk3, Qt 5, GStreamer, Webkit, Kodi, a large number of network-related and system-related utilities are supported.

Github: https://github.com/buildroot/buildroot

Official Git repo: https://gitlab.com/buildroot.org/buildroot/

Hancho is a simple, pleasant build system with few moving parts. Hancho fits comfortably in a single Python file and requires no installation, just copy-paste it into your source tree. Hancho is inspired by Ninja (for speed and simplicity) and Bazel (for syntax and extensibility). Like Ninja, it knows nothing about your build tools and is only trying to assemble and run commands as fast as possible. Unlike Ninja, you can use glob("*.cpp") and such to make things far less verbose. Like Bazel, you invoke build rules by calling them as if they were functions with keyword arguments. Unlike Bazel, you can create build rules that call arbitrary Python code (for better or worse). Hancho should suffice for small to medium sized projects.

How to use the OpenWRT compilation environment for cross-compilation of stuff.

An overview of the OpenRISC architecture and how to get started using it. Briefly talks about synthesizing an FPGA bitstream, setting up a development environment, and either emulating it or running it inside an FPGA. Also covers cross compiling an OS for it.