HelenOS
 | |
| OS family | Experimental |
|---|---|
| Working state | Current |
| Source model | Open Source |
| Latest release | 0.4.0 / Feb 14 2009 |
| Repository | |
| Platforms | IA-32, AMD64, SPARC V9, IA-64, PowerPC, ARM, MIPS |
| Kernel type | Microkernel |
| License | BSD |
| Official website | www.helenos.org |
HelenOS is an operating system based on a preemptible microkernel design. The source code of HelenOS is published under free software licences, making the operating system free software.
Technical Overview
HelenOS is based on a preemptible microkernel called SPARTAN. The microkernel handles multitasking, memory management and inter-process communication. It also provides kernel-based threads and supports symmetric multiprocessing.
Each process (called task) can contain several threads (preemptively scheduled by the kernel) which, in turn, can contain several fibrils scheduled cooperatively in user space. Device and file-system drivers, as well as other system services, are implemented in user-space tasks (servers).
Tasks communicate via HelenOS IPC, which is connection-oriented and asynchronous. It can be used to send small fixed-size messages, blocks of bytes or to negotiate sharing of memory. Messages can be forwarded without copying bulk data or mapping memory to the address space of middle-men tasks.
Development
HelenOS is partly hobbyist, partly academic, being developed mainly by staff and former and contemporary students of the Faculty of Mathematics and Physics at Charles University in Prague, with help from other contributors around the world.
The source code of HelenOS is published under the BSD licence, while some third-party components are available under the GNU General Public License, and others are public domain. Both of these licences are free software licences, making HelenOS free software.
Hardware Support
HelenOS runs on several different CPU architectures including ARM, AMD64 (x86-64), IA-32, IA-64 (Itanium), MIPS, PowerPC (32-bit only), and SPARC V9. There are also incomplete ports (in the old 0.2.x releases) to 64-bit PowerPC and the Xen hypervisor on IA-32. Most can be booted on real hardware, except for ARM and MIPS.
Support for peripheral devices is mostly limited to keyboards and display devices.
Research use
HelenOS originated as a school assignment for a team of students at the Faculty of Mathematics and Physics at Charles University, Prague. Since then HelenOS has been used by students as a target for school assignments and master theses.
References
External links
- HelenOS home page
- Porting SPARTAN kernel to SPARC V9 architecture
- Implementace souborového systému v operačním systému HelenOS, XXXII. konference EurOpen, sborník příspěvků, p. 149 - p. 157
- HelenOS IPC and Behavior Protocols
- Component-based General-purpose Operating System
 | This operating-system-related article is a stub. You can help Wikipedia by expanding it. |