Adaptive Domain Environment for Operating Systems
Adeos (Adaptive Domain Environment for Operating Systems) is a nanokernel hardware abstraction layer (HAL) or a hypervisor that operates between computer hardware and the operating system that runs on it.[1] It is distinct from other nanokernels, in that it is not just a low level layer for an outer kernel. Instead it is intended to run several kernels together, which makes it similar to virtualization technologies.
Adeos provides a flexible environment for sharing hardware resources among multiple operating systems, or among multiple instances of a single OS, thereby enabling multiple prioritized domains to exist simultaneously on the same hardware.
Adeos has been successfully inserted beneath the Linux kernel, opening a range of possibilities, such as SMP clustering, more efficient virtualization, patchless kernel debugging and real-time systems for Linux.
Unusually among HALs, Adeos can be loaded as a Linux loadable kernel module to allow another OS to run along with it. In fact Adeos was developed in the context of RTAI (Real-Time Application Interface) to modularize it and to separate the HAL from the real-time kernel.
Architecture
Adeos implements a queue of signals. Each time that a peripheral sends a signal, the different operating systems that are running in the machine are awakened, in turn, and must decide if they will accept (handle), ignore, discard, or terminate the signal. Signals not handled (or discarded) by an OS are passed to the next OS in the chain. Signals that are terminated are not propagated to latter stages.
See also
External links
References
- ^ "Adaptive Domain Environment for Operating Systems". whitepapers.zdnet.co.uk. February 15, 2001. Retrieved 2009-09-02. [dead link]