RTEMS

Infobox OS
name = RTEMS



caption =
developer = OAR Corporation
source_model = Open source
kernel_type =
supported_platforms = ARM, Blackfin, ColdFire, TI C3x/C4x, H8/300, x86, 68k, MIPS, Nios II, PowerPC, SuperH, SPARC, ERC32, LEON, Mongoose-V
ui =
family = Real-time operating systems
released =
latest_release_version = 4.9.0
latest_release_date = September 2008
latest_test_version = CVS head
latest_test_date =
marketing_target = Embedded systems
programmed_in =
prog_language =
language =
updatemodel =
package_manager =
working_state = Current
license = Modified GPL
website = [http://www.rtems.com/ www.rtems.com]

RTEMS (Real-Time Executive for Multiprocessor Systems) is a free open source real-time operating system (RTOS) designed for embedded systems.

The acronym RTEMS initially stood for "Real-Time Executive for Missile Systems", then became "Real-Time Executive for Military Systems" before changing to its current meaning. RTEMS development began in the late 1980s with early versions of RTEMS available via ftp as early as 1993. OAR Corporation is currently managing the RTEMS project in cooperation with a Steering Committee which includes user representatives.

RTEMS is designed for real-time, embedded systems and has been ported to various target processor architectures:

* ARM
* Blackfin
* Freescale ColdFire
* Texas Instruments C3x/C4x DSPs
* H8/300
* Intel 80386, Pentium, and above members of the x86 architecture
* 68k
* MIPS
* Nios II
* PowerPC
* SuperH
* SPARC

RTEMS is designed to support various open API standards including POSIX and uITRON. The API now known as the Classic RTEMS API was originally based upon the Real-Time Executive Interface Definition (RTEID) specification. RTEMS includes a port of the FreeBSD TCP/IP stack as well as support for various filesystems including Network file system and the FAT filesystem.

RTEMS does not provide any form of memory management or processes. In POSIX terminology, it implements a single process, multithreaded environment. This is reflected in the fact that RTEMS provides nearly all POSIX services other than those which are related to memory mapping, process forking, or shared memory. RTEMS closely correponds to POSIX Profile 52 which is "single process, threads, filesystem". [ [http://www.linuxdevices.com/news/NS3992179355.html Open Group pilots embedded real-time POSIX conformance testing ] ]

RTEMS is used in many application domains. The EPICS community includes multiple persons 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 (see Mars Reconnaissance Orbiter).cite web |url=http://trs-new.jpl.nasa.gov/dspace/bitstream/2014/39788/1/06-0474.pdf|title=Real Time Mars Approach Navigation aided by the Mars Network |accessdate=2008-01-25 |format=PDF |publisher=NASA]

RTEMS is distributed under a modified GPL licence, allowing linking RTEMS objects with other files without requiring 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 Ada programming language.

References

External links

* [http://www.rtems.com/ Official RTEMS website]
* [http://www.rtems.com/wiki/index.php/Main_Page Official RTEMS Wiki]
* [http://rtemscentre.edisoft.pt RTEMS CENTRE]