Zephyr (operating system)
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Developer | Linux Foundation, Wind River Systems |
---|---|
Written in | C |
OS family | Real-time operating systems |
Working state | Current |
Source model | Open source |
Initial release | 26 July 2016[1] |
Latest release | 4.0.0 / 15 November 2024[2][3] |
Repository | |
Marketing target | Internet of things, Embedded Systems |
Available in | English |
Platforms | ARM (Cortex-M, Cortex-R, Cortex-A), ARC, MIPS, Nios II, RISC-V, Xtensa, SPARC, x86, x86-64 |
Kernel type | Microkernel (pre-v1.6)[4][5][6] Monolithic (v1.6+)[5][6] |
License | Apache 2.0 |
Preceded by | Wind River Rocket |
Official website | www |
Zephyr (/ˈzɛf ər/) is a small real-time operating system (RTOS)[7] for connected, resource-constrained and embedded devices (with an emphasis on microcontrollers) supporting multiple architectures and released under the Apache License 2.0. Zephyr includes a kernel, and all components and libraries, device drivers, protocol stacks, file systems, and firmware updates, needed to develop full application software.[8]
It is named after Zephyrus, the ancient Greek god of the west wind.[9]
History
[edit]Zephyr originated from Virtuoso RTOS for digital signal processors (DSPs).[10][11] In 2001, Wind River Systems acquired Belgian software company Eonic Systems, the developer of Virtuoso. In November 2015, Wind River Systems renamed the operating system to Rocket, made it open-source and royalty-free.[11] Compared to Wind River's other RTOS, VxWorks, Rocket had much smaller memory needs, especially suitable for sensors and single-function embedded devices. Rocket could fit into as little as 4 KB of memory, while VxWorks needed 200 KB or more.[11]
In February 2016, Rocket became a hosted collaborative project of the Linux Foundation under the name Zephyr.[10][12][1] Wind River Systems contributed the Rocket kernel to Zephyr, but still provided Rocket to its clients, charging them for the cloud services.[13][11] As a result, Rocket became "essentially the commercial version of Zephyr".[13]
Since then, early members and supporters of Zephyr include Intel, NXP Semiconductors, Synopsys, Linaro,[14] Texas Instruments, DeviceTone, Nordic Semiconductor, Oticon, and Bose.[15]
As of January 2022[update], Zephyr had the largest number of contributors and commits compared to other RTOSes (including Mbed, RT-Thread, NuttX, and RIOT).[16]
Features
[edit]Zephyr intends to provide all components needed to develop resource-constrained and embedded or microcontroller-based applications. This includes, but is not limited to:[8]
- A small kernel
- A flexible configuration and build system for compile-time definition of required resources and modules
- A set of protocol stacks (IPv4 and IPv6, Constrained Application Protocol (CoAP), LwM2M, MQTT, 802.15.4, Thread, Bluetooth Low Energy, CAN)
- A virtual file system interface with several flash file systems for non-volatile storage (FatFs, LittleFS, NVS)
- Management and device firmware update mechanisms
Configuration and build system
[edit]Zephyr uses Kconfig and devicetree as its configuration systems, inherited from the Linux kernel but implemented in the programming language Python for portability to non-Unix operating systems.[17] The RTOS build system is based on CMake, which allows Zephyr applications to be built on Linux, macOS, and Microsoft Windows.[18]
Utility tool "West"
[edit]Zephyr has a general-purpose tool called "west" for managing repositories, downloading programs to hardware, etc.
Kernel
[edit]Early Zephyr kernels used a dual nanokernel plus microkernel design.[4][5][6] In December 2016, with Zephyr 1.6, this changed to a monolithic kernel.[5][6]
The kernel offers several features that distinguish it from other small OSes:[8]
- Single address space
- Multiple scheduling algorithms
- Highly configurable and modular for flexibility, with resources defined at compile-time
- Memory protection unit (MPU) based protection
- Asymmetric multiprocessing (AMP, based on OpenAMP) and symmetric multiprocessing (SMP) support
Security
[edit]A group is dedicated to maintaining and improving the security.[19] Also, being owned and supported by a community means the world's open source developers are vetting the code, which significantly increases security.[12]
See also
[edit]References
[edit]- ^ a b "The Linux Foundation Announces Project to Build Real-Time Operating System for Internet of Things Devices". Zephyr Project. Linux Foundation. 17 February 2016. Archived from the original on 2016-03-10.
- ^ "Zephyr v4.0.0". GitHub.
- ^ "Zephyr 4.0 Is Generally Available: Some Highlights". Zephyr blog.
- ^ a b Wasserman, Shawn (February 22, 2016). "How Linux's IoT Zephyr Operating System Works". Engineering.com.
- ^ a b c d Helm, Maureen (December 15, 2016). "Announcing Zephyr OS v1.6.0". Zephyr Project.
- ^ a b c d Wong, William G. (July 6, 2017). "Zephyr: A Wearable Operating System". Electronic Design.
- ^ "Meet Linux's little brother: Zephyr, a tiny open-source IoT RTOS". LinuxGizmos.com. 2016-02-17. Retrieved 2018-02-23.
- ^ a b c "Zephyr Project documentation: Introduction".
- ^ "West (Zephyr's meta-tool) — Zephyr Project Documentation". docs.zephyrproject.org.
- ^ a b Clarysse, Ivo (November 22, 2019). "Zephyr – An Operating System for IoT". Zephyr Project.
- ^ a b c d Turley, Jim (25 November 2015). "Wind River Sets Rocket RTOS on Free Trajectory". Electronic Engineering Journal. Techfocus Media. Retrieved 2018-02-23.
- ^ a b Guerrini, Federico (2016-02-19). "The Internet of Things Goes Open Source with Linux Foundation's Zephyr Project". Forbes. Retrieved 2017-01-12.
- ^ a b Patel, Niheer (17 February 2016). "Wind River Welcomes Linux Foundation's Zephyr Project". Wind River Systems. Archived from the original on 21 February 2016. Retrieved 18 February 2016.
- ^ Osborne, Charlie (2016-02-19). "The Linux Foundation's Zephyr Project: A custom operating system for IoT devices". ZDNet. CBS Interactive. Retrieved 2017-01-12.
- ^ "Zephyr Project – A proven RTOS ecosystem, by developers, for developers".
- ^ "Zephyr GitHub page". GitHub. January 26, 2022.
- ^ "scripts/ folder". GitHub. 12 May 2020.
- ^ "Application Development: Zephyr Project Documentation". Zephyr Project.
- ^ Wallen, Jack (2016-02-18). "Linux Foundation announces Zephyr Project, an open source IoT operating system". TechRepublic. CBS Interactive. Retrieved 2017-01-12.