XtratuM is a hypervisor based on para-virtualisation that provides one or more virtual execution environments for partitions.
A partition is an execution environment managed by the hypervisor which uses the virtualised services. Each partition consists of one or more concurrent processes (implemented by the operating system of each partition), that share access to processor resources based upon the requirements of the application.
The partition code can be:
- an application compiled to be executed on a bare-machine
- a real-time operating system (or runtime support) and its applications
- a general purpose operating system and its applications
Partitions need to be virtualised to be executed on top of a hypervisor.
Depending on the underlaying hardware, XtratuM provides:
- XAL (XtratuM Abstraction Layer): a mininal layer to execute bare-C partitions
- PartiKle: a real-time operating system with an POSIX PSE52 API
- Lithos: a real-time operating system ARINC-653 compliant
- Linux OS