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 develo ...

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, which ...

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'' as ...

, while using

cross-compilation A cross compiler is a compiler capable of creating executable code for a platform other than the one on which the compiler is running. For example, a compiler that runs on a PC but generates code that runs on an Android smartphone is a cross ...

to allow building for multiple target platforms on a single Linux-based development system. Buildroot can automatically build the required cross-compilation

toolchain In software, a toolchain is a set of programming tools that is used to perform a complex software development task or to create a software product, which is typically another computer program or a set of related programs. In general, the tools form ...

, 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 ope ...

image, and generate a

boot loader A bootloader, also spelled as boot loader or called boot manager and bootstrap loader, is a computer program that is responsible for booting a computer. When a computer is turned off, its softwareincluding operating systems, application code, a ...

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 x86 (also known as 80x86 or the 8086 family) is a family of complex instruction set computer (CISC) instruction set architectures initially developed by Intel based on the Intel 8086 microprocessor and its 8088 variant. The 8086 was introd ...

ARM In human anatomy, the arm refers to the upper limb in common usage, although academically the term specifically means the upper arm between the glenohumeral joint (shoulder joint) and the elbow joint. The distal part of the upper limb between the ...

, 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 Inc., App ...

. Numerous architectures and their variants are supported; Buildroot also comes with default configurations for several off-the-shelf available embedded boards, such as

Cubieboard Cubieboard is a single-board computer, made in Zhuhai, Guangdong, China. The first short run of prototype boards were sold internationally in September 2012, and the production version started to be sold in October 2012. It can run Android 4 ICS ...

Raspberry Pi Raspberry Pi () is a series of small single-board computers (SBCs) developed in the United Kingdom by the Raspberry Pi Foundation in association with Broadcom. The Raspberry Pi project originally leaned towards the promotion of teaching basic c ...

and

SheevaPlug The SheevaPlug is a "plug computer" designed to allow standard computing features in as small a space as possible. As one of the first such computers on the market, the device has a 1.2 GHz Marvell Technology Group, Marvell Kirkwood 6281 AR ...

. 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 com ...

project that creates an

embedded operating system An embedded operating system is an operating system for embedded computer systems. Embedded operating systems are computer systems designed to increase functionality and reliability for achieving a specific task. Resource efficiency comes at the ...

, 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 In telecommunications, a customer-premises equipment or customer-provided equipment (CPE) is any terminal and associated equipment located at a subscriber's premises and connected with a carrier's telecommunication circuit at the demarcation poi ...

(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 not ...

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. Ov ...

, as well as the C standard libraries that belong to various preconfigured development environments, such as those provided by

Linaro Linaro is an engineering organization that works on free and open-source software such as the Linux kernel, the GNU Compiler Collection (GCC), QEMU, power management, graphics and multimedia interfaces for the ARM family of instruction sets and im ...

. 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 Package may refer to: Containers or Enclosures * Packaging and labeling, enclosing or protecting products * Mail, items larger than a letter * Chip package or chip carrier * Electronic packaging, in electrical engineering * Automotive package, in ...

, 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 wo ...

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. Kernel ...

applications, system utilities, and

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

. 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 software, free (GNU General Public License, GPL'ed) read-only Linux kernel, Linux file system designed for simplicity and space-efficiency. It is mainly used in embedded system, embedded an ...

JFFS2 Journalling Flash File System version 2 or JFFS2 is a log-structured file system for use with flash memory devices. It is the successor to JFFS. JFFS2 has been included into the Linux kernel since September 23, 2001, when it was merged into the ...

, romfs,

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 al ...

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 (MT ...

. 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 (Free software), four freedoms to run, study, share, and modify the software. The license was th ...

(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 LWN.net is a computing webzine with an emphasis on free software and software for Linux and other Unix-like operating systems. It consists of a weekly issue, separate stories which are published most days, and threaded discussion attached to ever ...

, April 6, 2016, by Nathan Willis {{Embedded systems Build automation Embedded Linux Free computer programming tools

See also

References

External links