Buildroot is a set of

Makefile In software development, Make is a build automation tool that automatically builds executable programs and libraries from source code by reading files called ''Makefiles'' which specify how to derive the target program. Though integrated ...

s and patches that simplifies and automates the process of building a complete and bootable

Linux Linux ( or ) is a family of open-source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically packaged as a Linux distribution, whi ...

environment for an

embedded system An embedded system is a computer system—a combination of a computer processor, computer memory, and input/output peripheral devices—that has a dedicated function within a larger mechanical or electronic system. It is ''embedded ...

, 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 In a computer file system, and primarily used in the Unix and Unix-like operating systems, the root directory is the first or top-most directory in a hierarchy. It can be likened to the trunk of a tree, as the starting point where all branche ...

, compile a

Linux kernel The Linux kernel is a free and open-source, monolithic, modular, multitasking, Unix-like operating system kernel. It was originally authored in 1991 by Linus Torvalds for his i386-based PC, and it was soon adopted as the kernel for the GNU ...

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. Buildroot is primarily intended to be used with small or embedded systems based on various

computer architectures In computer engineering, computer architecture is a description of the structure of a computer system made from component parts. It can sometimes be a high-level description that ignores details of the implementation. At a more detailed level, the ...

and

instruction set architecture In computer science, an instruction set architecture (ISA), also called computer architecture, is an abstract model of a computer. A device that executes instructions described by that ISA, such as a central processing unit (CPU), is called an ...

s (ISAs), including x86, ARM, MIPS and

PowerPC PowerPC (with the backronym Performance Optimization With Enhanced RISC – Performance Computing, sometimes abbreviated as PPC) is a reduced instruction set computer (RISC) instruction set architecture (ISA) created by the 1991 Apple– IBM– ...

. Numerous architectures and their variants are supported; Buildroot also comes with default configurations for several off-the-shelf available embedded boards, such as Cubieboard, Raspberry Pi and SheevaPlug. Several third-party projects and products use Buildroot as the basis for their build systems, including the

OpenWrt OpenWrt (from ''open wireless router'') is an open-source project for embedded operating systems based on Linux, primarily used on embedded devices to route network traffic. The main components are Linux, util-linux, musl, and BusyBox. All ...

project that creates an embedded operating system, and

firmware In computing, firmware is a specific class of computer software that provides the low-level control for a device's specific hardware. Firmware, such as the BIOS of a personal computer, may contain basic functions of a device, and may provide h ...

for the customer-premises equipment (CPE) used by the

Google Fiber Google Fiber is part of the Access division of Alphabet Inc. It provides fiber-to-the-premises service in the United States, providing broadband Internet and IPTV to a small and slowly increasing number of locations. In mid-2016, Google Fiber ...

broadband service. Multiple

C standard libraries The C standard library or libc is the standard library for the C programming language, as specified in the ISO C standard. ISO/IEC (2018). '' ISO/IEC 9899:2018(E): Programming Languages - C §7'' Starting from the original ANSI C standard, it was ...

are supported as part of the toolchain, including the

GNU C Library The GNU C Library, commonly known as glibc, is the GNU Project's implementation of the C standard library. Despite its name, it now also directly supports C++ (and, indirectly, other programming languages). It was started in the 1980s by ...

uClibc __NOTOC__ In computing, uClibc (sometimes written µClibc) is a small C standard library intended for Linux kernel-based operating systems for embedded systems and mobile devices. uClibc was written to support μClinux, a version of Linux n ...

and

musl musl is a C standard library intended for operating systems based on the Linux kernel, released under the MIT License. It was developed by Rich Felker with the goal to write a clean, efficient and standards-conformant libc implementation. ...

, as well as the C standard libraries that belong to various preconfigured development environments, such as those provided by Linaro. Buildroot's build configuration system internally uses Kconfig, which provides features such as a menu-driven interface, handling of dependencies, and contextual help; Kconfig is also used by the Linux kernel for its source-level configuration. Buildroot is organized around numerous automatically downloaded packages, which contain the

source code In computing, source code, or simply code, is any collection of code, with or without comments, written using a human-readable programming language, usually as plain text. The source code of a program is specially designed to facilitate the ...

of various

userspace A modern computer operating system usually segregates virtual memory into user space and kernel space. Primarily, this separation serves to provide memory protection and hardware protection from malicious or errant software behaviour. Kerne ...

applications, system utilities, and

libraries A library is a collection of Document, materials, books or media that are accessible for use and not just for display purposes. A library provides physical (hard copies) or electronic media, digital access (soft copies) materials, and may be a ...

. Root file system images, which are the final results, may be built using various

file system In computing, file system or filesystem (often abbreviated to fs) is a method and data structure that the operating system uses to control how data is stored and retrieved. Without a file system, data placed in a storage medium would be one larg ...

s, including

cramfs The compressed ROM/RAM file system (or cramfs) is a free (GPL'ed) read-only Linux file system designed for simplicity and space-efficiency. It is mainly used in embedded and small-footprint systems. Unlike a compressed image of a conventional f ...

, JFFS2,

romfs In computing, romfs (ROM filesystem) is an extremely simple file system lacking many features, intended for burning important files onto an EEPROM. It is available on Linux Linux ( or ) is a family of open-source Unix-like operating ...

SquashFS Squashfs is a compressed read-only file system for Linux. Squashfs compresses files, inodes and directories, and supports block sizes from 4 KiB up to 1 MiB for greater compression. Several compression algorithms are supported. Squashfs is ...

and

UBIFS UBIFS (UBI File System, more fully Unsorted Block Image File System) is a flash file system for unmanaged flash memory devices. UBIFS works on top of an UBI (unsorted block image) layer, which is itself on top of a memory technology device (M ...

. Buildroot is

free and open-source software Free and open-source software (FOSS) is a term used to refer to groups of software consisting of both free software and open-source software where anyone is freely licensed to use, copy, study, and change the software in any way, and the source ...

, maintained by Peter Korsgaard and licensed under version 2 or later of the

GNU General Public License The GNU General Public License (GNU GPL or simply GPL) is a series of widely used free software licenses that guarantee end users the four freedoms to run, study, share, and modify the software. The license was the first copyleft for general ...

(GPL). The project started in 2001, with initial intentions to serve as a testbed for uClibc. New releases are made available every three months.

References

External links

*
Buildroot: What's new?
Embedded Linux Conference 2014, by Thomas Petazzoni
Buildroot: A deep dive into the core
Embedded Linux Conference Europe 2014, by Thomas Petazzoni
Deciding between Buildroot and Yocto
LWN.net, April 6, 2016, by Nathan Willis {{Embedded systems Build automation Embedded Linux Free computer programming tools

See also

References

External links