- What is Fiasco?
- Fiasco is a new µ-kernel (microkernel) running on x86 PCs
intended to be compatible with the L4 µ-kernel
for x86. It
implements the L4 ABI as defined in the L4/x86 Reference
The Fiasco kernel can be used to construct flexible
systems. We at TU Dresden use it as a base for our DROPS system which supports
running real-time and time-sharing applications concurrently on
one computer. However, Fiasco is not only suitable for big and
complex systems, but also for small, embedded applications.
- What are Fiasco's distinctive features (i.e.,
- Fiasco is a preemptible real-time kernel supporting hard
priorities. It uses non-blocking synchronization for its
kernel objects. This guarantees priority inheritance and makes
sure that runnable high-priority processes never block waiting
for lower-priority processes.
When using L4Linux on
top of Fiasco, hard-real-time applications can share one machine
with time-sharing (Linux) applications.
Fiasco is a real, second-generation µ-kernel protecting
applications in address spaces. Thanks to its efficient task
and context switching mechanism and its performace-oriented
design, the performance penalties induced by address-space
security are neglible - much smaller than in older,
first-generation µ-kernels like Mach.
- The original L4
µ-kernel for x86 has some
shortcomings which we intend to fix with this new
implementation. The Fiasco kernel:
- can be studied and maintained better because it has been
written in a high-level language (C++)
- has better real-time properties than L4/x86 because it can
be preempted at almost any time
- is freely redistributable under the GPL
Please see also the section, ``Why
another kernel?,'' in the Fiasco FAQ.
- Current release
- The current release is version 1.2.
It is release-quality software.
This release is capable of running L4Linux,
DROPS, and many
For details on Fiasco's L4 compatibility, please see the status page.
- Fiasco is freely available under the
Public License from the download
For questions about other licensing variants, please contact
- Developers welcome!
- Fiasco is Open-SourceTM
software; you are welcome to use it or join developing it.
Please consider subscribing to our developer's mailing list
The discussion language for this mailing list is
Before posting to the mailing list, you may want to check out the
list archive and the FAQ.
- Reporting bugs
- To report a bug in the Fiasco µ-kernel, please use the
l4-hackers mailing list. See
the previous point for more information on this list.
Last modified: Thu Mar 29 2007, 10.48:41 CEST