This web-site provides the qualification data package for the open source RTEMS real-time operating system with symmetric multi-processing capabilities, for use in space applications and compliant to the ECSS applicable standards for software engineering and software product assurance. It provides a starting point for the European space industry to qualify their application software on bespoke LEON based multi-core processors.
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Space profile definition

The RTEMS API is rich and powerful, but not all of those functions are relevant for typical space applications. In collaboration with the European space community, a so-called space profile was defined, listing the qualified subset of RTEMS.
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BSP support

The qualification has been performed for the LEON3 (GR712RC) and LEON4 (GR740) multi-core space qualified processors, both in classic RTEMS (single core) and SMP (dual and quad-core) configurations.
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Qualification Data Packet (QDP)

A QDP that enables RTEMS SMP for space

Classic & SMP

RTEMS Mainline

Full Open Source

ECSS/Category C

A prequalification toolkit allows end-users to qualify their space applications on bespoke (space-qualified) hardware. The primary focus has been on qualifying the SMP elements of the RTEMS super core. The target application area is payload (instrument) data processing, the exact scope is defined in space profile subset .

The base-line target platforms are the Cobham Gaisler GR712RC (Leon3 dual core); and GR740 (LEON4 quad core) System-On-Chips and associated Gaisler reference boards.

The pre-qualification toolkit uses the GCC-based cross-compiler provided by the RTEMS Source Builder as baseline (RSB -currently at GCC v10.2.1).

Full alignment with the (qualified) mathematical library for critical system (LibmCS) .

The below diagram shows the full toolchain. The blue box depicts the RTEMS provided elements. These elements are:

The orange boxes depicts the elements which should be provided by the end-user. The software application, tests, documentation and the hardware qualification.

ECSS compliance

All verification and validation evidences are included. They are obtained from analysis, testing and proof for the identified target configurations, in the form of documents required by ECSS-E-ST-40C and ECSS-Q-ST-80C Rev 1

Automatic Test suite

Curated test suite and all supporting resources required to automatically execute the test suite and reproduce the test evidence for each identified target configuration.

Open source

The qualification toolkit will become fully open source and free of charge. The intent is to keep this activity as close as possible to the RTEMS main-line evolution.


26/01/22: The QDPs are delivered. The QDPs are delivered “as-is” without warranty of any kind. Note that the contents of the QDPs can change without notice. Also, note that the QDP provides a solid pre-qualification baseline, but still requires activities to be performed by end-users to be considered a fully qualified product! All QDP documentation is provided under the Creative Commons Attribution-ShareAlike 4.0 International Public License. For the RTEMS source code, the applicable license information can be found here .
26/01/22: The ISVV activities are started in december 2021.
27/01/22: Technical Note Space Profile has been deleted from the Download page. Many more functions have been qualified than those listed in the before versions of the space Profile . The current QDP version is 3. You can find the complete list of qualified API in section "4.10 Pre-Qualified Interfaces" of the SCF.
15/06/22: The release 4 is available to download. Main changes are: 1) It contains a warranty release issued for project Qualification of RTEMS Symmetric Multiprocessing (SMP); 2) The RTEMS baseline has been updated and the QDP patches has been partially merged; 3) Most of the validation test have been integrated in RTEMS main line; 4) The previous RTEMS baseline contained a bug which could result in a non-monotonic CLOCK_MONOTONIC; 5) Significant changes in the Software Requirement Specification (SRS) and Software Verification Report (SVR), see the change log of the documents. More details can be found in the SCF.

Pre-qualification what does that mean?

No kernel separation

Partial doc

Bespoke Hardware

Needed tailoring

The RTEMS pre-qualification contains a set of features that is described in the space profile. In case features are needed in your project that are outside of this space profile, then these additional features would need to be qualified in the scope of your project. Typically this applies to drivers (legacy / reuse / heritage)

The RTEMS pre-qualification has been run on two Gaisler reference boards (GR712RC and GR740) under a limited number of configurations (i.e. CPU speeds, memory and cache configuration setting). The tests should be repeated on the hardware applicable in the end user project to gather test evidence for the project's qualification.

RTEMS pre-qualification does not reduce the need on qualification of RTEMS and ASW combined. RTEMS is like any other re-used SW library and needs qualification and ISVV. RTEMS is statically linked (as a library) to the application code using a flat memory model without protection (no user / kernel space distinction); this implies that ASW behavior may influence RTEMS and the other way around.