XtratuM is a hypervisor specially designed for real-time embedded systems.

Although hypervisor (or virtual machine monitor, VMM) has been widely used in mainframe systems since the 60's, it has not been used in the embedded devices until recently.

It is important to note that an hypervisor is an "enabling" technology, rather than a technology to solve problems. The hypervisor provides a framework to run several operating systems (or real-time executives) in a robust partitioned environment. XtratuM can be used to build a MILS (Multiple Independent Levels of Security) architecture.

PaRTiKle is the RTOS complement for XtratuM to develop real-time applications. It provides a POSIX PSE51 interface. PaRTiKle can be configured to run as: a XtratuM partition, a stand-alone kernel and a regular Linux process. For more information about PaRTiKle in www.e-rtl.org/partikle.

Are XtratuM and PaRTiKle free?

Yes.

Both XtratuM and PaRTiKle are covered by the GPLv2 and applications that use them though standard system calls are not considered derived work. You can develop your own proprietary applications for free.

Current status

XtratuM 2.1.0 for LEON2

XtratuM has been ported to the Sparc V8 arquitecture, and the architecture and API has been adapted to meet the requirements of highly critical systems (spatial requirements). Although ARINC-653 is not directly applicable to hypervisor systems, we used it as reference. The more relevant features of XtratuM are:

• Cyclic scheduling.
• System definition (partitions and allocated resources) defined via a XML configuration file.
• Health monitoring support.
• Inter-partition communication via sampling and queuing ports (ARINC-653 terminology).
• Supervisor and standard partitions.
• Strong temporal isolation.
• Limited spatial isolation (LEON2 does not have MMU).

XtratuM 2.0 for x86

This second version is a complete redesign and a new implementation. It is an hypervisor. Only the name was keept from the first version. It is in Alpha state.

Now, we are working on XtratuM 2.2.0. It will be the second version for the LEON2. We plan to finish this second LEON2 version by April 2009.