An embedded operating system is an

operating system An operating system (OS) is system software that manages computer hardware, software resources, and provides common services for computer programs. Time-sharing operating systems schedule tasks for efficient use of the system and may also in ...

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 cost of losing some functionality or granularity that larger computer operating systems provide, including functions that may not be used by the specialized applications run. Depending on the method used for multitasking, this type of OS is frequently considered a

real-time operating system A real-time operating system (RTOS) is an operating system (OS) for real-time applications that processes data and events that have critically defined time constraints. An RTOS is distinct from a time-sharing operating system, such as Unix, which m ...

or ''RTOS''. Embedded systems are mostly used as Real-time operating systems. All embedded systems contain a

processor Processor may refer to: Computing Hardware * Processor (computing) **Central processing unit (CPU), the hardware within a computer that executes a program *** Microprocessor, a central processing unit contained on a single integrated circuit (I ...

and

software Software is a set of computer programs and associated documentation and data. This is in contrast to hardware, from which the system is built and which actually performs the work. At the lowest programming level, executable code consists ...

. There must be a place for

embedded software Embedded software is computer software, written to control machines or devices that are not typically thought of as computers, commonly known as embedded systems. It is typically specialized for the particular hardware that it runs on and has time ...

to store the

executable code In computing, executable code, an executable file, or an executable program, sometimes simply referred to as an executable or binary, causes a computer "to perform indicated tasks according to encoded instructions", as opposed to a data file ...

and temporary storage for run-time data manipulations. These take the form of

ROM Rom, or ROM may refer to: Biomechanics and medicine * Risk of mortality, a medical classification to estimate the likelihood of death for a patient * Rupture of membranes, a term used during pregnancy to describe a rupture of the amniotic sac * ...

and

RAM Ram, ram, or RAM may refer to: Animals * A male sheep * Ram cichlid, a freshwater tropical fish People * Ram (given name) * Ram (surname) * Ram (director) (Ramsubramaniam), an Indian Tamil film director * RAM (musician) (born 1974), Dutch * ...

, respectively. All embedded systems must also contain some form of inputs and outputs to function. Within the exception of these few common features, the rest of the

embedded hardware 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 ...

is usually unique and varies from application to application. The hardware running an embedded operating system can be very limited in resources; therefore the embedded design of these operating systems may have a narrow scope tailored to a specific application to achieve the desired operation under these constraints. The embedded operating system that organizes and controls the hardware usually determines the rest of the embedded hardware needed. To take better advantage of the processing power of the CPU, software developers may write critical code directly in

assembly Assembly may refer to: Organisations and meetings * Deliberative assembly, a gathering of members who use parliamentary procedure for making decisions * General assembly, an official meeting of the members of an organization or of their representa ...

. This ''machine efficient'' language can potentially result in gains in speed and

determinism Determinism is a philosophical view, where all events are determined completely by previously existing causes. Deterministic theories throughout the history of philosophy have developed from diverse and sometimes overlapping motives and consi ...

at the cost of portability and

maintainability In engineering, maintainability is the ease with which a product can be maintained to: * correct defects or their cause, * Repair or replace faulty or worn-out components without having to replace still working parts, * prevent unexpected working ...

. Often, embedded operating systems are written entirely in more portable languages, like C, however. An important difference between most embedded operating systems and desktop operating systems is that the application, including the operating system, is usually statically linked into a single executable image. Unlike a desktop operating system, the embedded operating system does not load and execute many applications. This means that the system is only able to run a few application(s).

History

Early embedded operating systems

In the late 1970s, the concept of a real-time multitasking kernel was proposed. In the 1980s, while the embedded systems applications became more complex, the embedded operating system with a real-time multitasking kernel could not meet the requirement of embedded development. It began to develop into a complete real-time multitasking Operating System (

RTOS A real-time operating system (RTOS) is an operating system (OS) for real-time applications that processes data and events that have critically defined time constraints. An RTOS is distinct from a time-sharing operating system, such as Unix, which ...

) that included a network, file, development and

debugging In computer programming and software development, debugging is the process of finding and resolving '' bugs'' (defects or problems that prevent correct operation) within computer programs, software, or systems. Debugging tactics can involve in ...

environment. Nowadays, RTOS has formed an industry in the world. The world's first commercial embedded real-time kernel (VRTX32) was developed by Ready System in 1981. Then in 1993, Ready System and the famous Silicon Valley embedded software company Microtec Research Merger developed two new RTOS kernels VRTX32 and VRTXsa, based on VRTXmc. At the same time, VRTX integrated development environment (Spectra) appeared.

Microsoft Microsoft Corporation is an American multinational technology corporation producing computer software, consumer electronics, personal computers, and related services headquartered at the Microsoft Redmond campus located in Redmond, Washing ...

, also released its own embedded 460 operating system in 1996. The embedded operating system is

WinCE Windows Embedded Compact, formerly Windows Embedded CE, Windows Powered and Windows CE, is an operating system subfamily developed by Microsoft as part of its Windows Embedded family of products. Unlike Windows Embedded Standard, which is base ...

, which was originally based on

Windows 95 Windows 95 is a consumer-oriented operating system developed by Microsoft as part of its Windows 9x family of operating systems. The first operating system in the 9x family, it is the successor to Windows 3.1x, and was released to manufacturin ...

in the 1.0 version, they subsequently released other versions, supporting

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 th ...

, SH4, MIPS and other processor architectures. WinCE is now defunct, with mainstream support discontinued in 2018.

Modern embedded systems

Nowadays, many embedded devices are used in the system of

Internet of Things The Internet of things (IoT) describes physical objects (or groups of such objects) with sensors, processing ability, software and other technologies that connect and exchange data with other devices and systems over the Internet or other comm ...

and hundreds of sensors are used in a car. Compared with the traditional embedded system, the Internet of Things system requires lower power consumption, more safety and reliability, and has the ability of

ad hoc network An ad hoc network refers to technologies that allow network communications on an ad hoc basis. Associated technologies include: *Wireless ad hoc network *Mobile ad hoc network * Vehicular ad hoc network ** Intelligent vehicular ad hoc network * Prot ...

. The communication section needs to meet the conversion between various communication protocols, and the application layer must have the ability of

cloud computing Cloud computing is the on-demand availability of computer system resources, especially data storage ( cloud storage) and computing power, without direct active management by the user. Large clouds often have functions distributed over mul ...

. The emergence of Smartphones have also resulted Due to this, new embedded operating systems have emerged and become popular, like

Embedded Linux Operating systems based on the Linux kernel are used in embedded systems such as consumer electronics (eg. set-top boxes, smart TVs and personal video recorders (PVRs)), in-vehicle infotainment (IVI), networking equipment (such as routers, switch ...

(including

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 ...

Zeroshell Zeroshell is a small open-source Linux distribution for servers and embedded systems which aims to provide network services. Its administration relies on a web-based graphical interface; no shell is needed to administer and configure it. Zer ...

, Android,

LineageOS LineageOS is an Android-based operating system for smartphones, tablet computers, and set-top boxes, with mostly free and open-source software. It is the successor to CyanogenMod, from which it was forked in December 2016, when Cyanogen Inc. a ...

LEDE Lede may refer to: * Lead paragraph (US English), the first paragraph of a composition Places * Lede, Belgium, a municipality in Flanders * Lède, a river in France * Lede Formation, a geologic formation in Belgium People * Marquess of Lede of ...

LibreCMC LibreCMC is a Linux-libre distribution for computers with minimal resources, such as the Ben NanoNote, ath9k-based Wi-Fi routers, and other hardware with emphasis on free software. Based on OpenWrt, the project's goal is to aim for compliance wit ...

etc.,),

NetBSD NetBSD is a free and open-source Unix operating system based on the Berkeley Software Distribution (BSD). It was the first open-source BSD descendant officially released after 386BSD was forked. It continues to be actively developed and is a ...

, ThreadX,

FreeRTOS FreeRTOS is a real-time operating system kernel for embedded devices that has been ported to 35 microcontroller platforms. It is distributed under the MIT License. History The FreeRTOS kernel was originally developed by Richard Barry around ...

etc., Many

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 ...

-based projects, toolkits, frameworks etc., have also emerged for embedded systems. Some notable examples include

OpenEmbedded OpenEmbedded is a build automation framework and cross-compile environment used to create Linux distributions for embedded devices. The OpenEmbedded framework is developed by the OpenEmbedded community, which was formally established in 2003. Ope ...

BusyBox BusyBox is a software suite that provides several Unix utilities in a single executable file. It runs in a variety of POSIX environments such as Linux, Android, and FreeBSD, although many of the tools it provides are designed to work with in ...

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 ...

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. O ...

libc 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 ...

buildroot 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 ...

etc.,

References

{{DEFAULTSORT:Embedded Operating System Embedded operating system

History

Early embedded operating systems

Modern embedded systems

See also

References