ARINC-653 based

ARINC-653 specification defines an APplication EXecutive (APEX) for space and time partitioning that may be used wherever multiple applications need to share a single processor and memory, in order to ensure an exclusive access of physical and temporal resources to the applications, while sharing computer resources, and guarantee that one application cannot bring down another in the event of application failure.

In the case of embedded systems, particularly avionics systems, ARINC 653 standard defines a partitioning scheme. Although this standard was not designed to describe how a hypervisor must operate, some parts of the model are quite close to the functionality provided by a hypervisor. The XtratuM API and internal operations resemble the ARINC 653 standard, but XtratuM is not an ARINC 653 compliant system. The hypervisor provides the ARINC-653 partition management, inter-partition communications, health monitor, scheduling policy and other functionalities to accurately been adapted to the ARINC-653 standard.

Depending on the underlying system and the complexity required, XtratuM provides execution environments based on the ARINC-653 standard . To have more detailed information see below.

  • LithOS

    LithOS is para-virtualised guest operating system which uses the services provided by XtratuM to offer the complete ARINC-653 APEX to the applications. LithOS implements the process concept presented in the ARINC-653 standard which is not present in XtratuM . Processes may operate concurrently in order to satisfy the application requirements. LithOS adds the multi-process support, the communication between processes and the process scheduler. LithOS uses the services provided by XtratuM to complete the mechanisms required to develop application based on ARINC-653.

    LithOS provides the following services:

    • Partition management.
    • Process management.
    • Time management.
    • Inter-partition communication.
    • Intra-partition communication.
    • Health monitoring.
  • Industrialization of LithOS (Financed by IVACE and cofinanced by FEDER)

    The qualification or industrialization of Lithos is evolving software, Lithos, from its current status as a prototype to the level of maturity necessary for it to be considered suitable for use in critical systems, according to a B level for space missions of the European Space Agency, as defined by the ECSS standards. This project began in April 2014 and will end in February 2015.

  • µLithOS

    µLithOS is a subset of LithOS that offers a lighter execution by restricting some services as defined in ARINC-653 Part 4. It is defined for systems that do not require the size, complexity and features of the full specification, provididing a simpler guest real-time operating system that can be more easily qualified.

    µLithOS provides the following services:

    • Partition management.
    • Time management.
    • Inter-partition communication.
    • Health monitoring.