Buildroot is a set of Makefiles and patches that simplifies and automates the process of building a complete and bootable Linux environment for an embedded system, while using cross-compilation to allow building for multiple target platforms on a single Linux-based development system.

Buildroot can automatically build the required cross-compilation toolchain, create a root file system, compile a Linux kernel image, and generate a boot loader for the targeted embedded system, or it can perform any independent combination of these steps.

For example, an already installed cross-compilation toolchain can be used independently, while Buildroot only creates the root file system.

[8][9]: 25  Several third-party projects and products use Buildroot as the basis for their build systems, including the OpenWrt project that creates an embedded operating system, and firmware for the customer-premises equipment (CPE) used by the Google Fiber broadband service.

Buildroot is organized around numerous automatically downloaded packages, which contain the source code of various userspace applications, system utilities, and libraries.