RTEMS

RTEMS
Developer	OAR Corporation
Written in	Ada, C
OS family	Real-time operating system
Working state	Current
Source model	Open source
Initial release	1993; 31 years ago
Latest release	5.1 / August 25, 2020; 4 years ago
Repository	git.rtems.org
Marketing target	Embedded systems
Available in	English
Platforms	ARM, Blackfin, ColdFire, TI C3x/C4x, H8/300, x86, 68k, LatticeMico32, MIPS (Mongoose-V), Nios II, OpenRISC, PowerPC, SuperH, SPARC (ERC32, LEON)
Kernel type	Real-time
Default; user interface	Command-line
License	Modified GPL
Official website	www.rtems.org

Real-Time Executive for Multiprocessor Systems (RTEMS), formerly Real-Time Executive for Missile Systems, and then Real-Time Executive for Military Systems, is a real-time operating system (RTOS) designed for embedded systems. It is free and open-source software.

Development began in the late 1980s with early versions available via File Transfer Protocol (ftp) as early as 1993. OAR Corporation is currently managing the RTEMS project in cooperation with a steering committee which includes user representatives.

Design

RTEMS is designed for real-time, embedded systems and to support various open application programming interface (API) standards including Portable Operating System Interface (POSIX) and µITRON. The API now known as the Classic RTEMS API was originally based on the Real-Time Executive Interface Definition (RTEID) specification. RTEMS includes a port of the FreeBSD Internet protocol suite (TCP/IP stack) and support for various file systems including Network File System (NFS) and File Allocation Table (FAT).

RTEMS provides extensive multi-processing and memory-management services, and even a System-database alongside many other facilities. It has extensive documentation.

Architectures

RTEMS has been ported to various target processor architectures:

ARM
Atmel AVR
Blackfin
Freescale, now NXP ColdFire
Texas Instruments – C3x/C4x DSPs
Intel – x86 architecture members 80386, Pentium, and above
LatticeMico32
68k
MIPS
Nios II
OpenRISC
PowerPC
Renesas – H8/300, M32C, M32R, SuperH
RISC-V RV32, RV64 using QEMU
SPARC – ERC32, LEON, V9

Uses

RTEMS is used in many application domains. The Experimental Physics and Industrial Control System (EPICS) community includes multiple people who are active RTEMS submitters. RTEMS is also popular for space uses since it supports multiple microprocessors developed for use in space including SPARC ERC32 and LEON, MIPS Mongoose-V, ColdFire, and PowerPC architectures, which are available in space hardened models. RTEMS is currently orbiting Mars as part of the Electra software radio on NASA's Mars Reconnaissance Orbiter,^[2] and the ESA's Trace Gas Orbiter.^[3]

License

RTEMS is distributed under a modified GNU General Public License (GPL), allowing linking RTEMS objects with other files without needing the full executable to be covered by the GPL. This license is based on the GNAT Modified General Public License with the language modified to not be specific to the programming language Ada.

References

^ "RTEMS 5.1 Released". 2020-08-25. Retrieved 2020-10-02.
^ "Real Time Mars Approach Navigation aided by the Mars Network" (PDF). NASA. Archived from the original (PDF) on 2006-09-30. Retrieved 2008-01-25.
^ "NASA radio on Europe's new Mars Orbiter aces relay test". Retrieved 2016-12-01.

External links

[1] "RTEMS 5.1 Released". 2020-08-25. Retrieved 2020-10-02.

[NASA-2] "Real Time Mars Approach Navigation aided by the Mars Network" (PDF). NASA. Archived from the original (PDF) on 2006-09-30. Retrieved 2008-01-25.

[3] "NASA radio on Europe's new Mars Orbiter aces relay test". Retrieved 2016-12-01.

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