What is DOpE?
DOpE is an acronym for 'Desktop Operating Environment'. It is a
windowing system for the real-time operating system
DROPS, which is
devloped at the OS-Group in Dresden. DROPS is based on the microkernel
Fiasco (an implementation of the L4 API). DOpE provides the real-time
facilities of DROPS at the user interface level. So what does that mean?
Real-time? A real-time operating system assures that the processing
time demands of certain tasks get satisfied.
There are several application areas where such guaranties are needed (or nice
to have), such as burning a CDR, multimedia streaming or control systems.
A basic property of such tasks is their predicability of their behaviour.
They normaly do their tasks periodically by consuming a fixed amount of
processing time to effect a fixed amount of data. When interactivity
comes into play (this is the case for DOpE), things get tricky because
the behaviour of the user is not predicable. Subordinating the user
lower than concurrently running real-time tasks is not sufficient since
a user has its own demands (reponse latency, ergonomy). DOpE tries to
solve this conflict. If you want to know how - I recommend reading my
diploma thesis about this topic. You can find it here:
There is also a technical report that presents the overall architecture
of DOpE and highlights the mechanisms used for its real-time capability.
Is DOpE available for download?
Yes, it is available via the OS Groups's remote Subversion repository
under the terms of the GNU General Public Licence. For more information
about the GNU General Public Licence visit the official GNU website:
You will need the L4 Environment and DICE to build DOpE. These packages are also
available at our repository:
To check out only DOpE from the repository:
$ svn checkout -N http://svn.tudos.org/repos/tudos/trunk/l4/pkg/dope
If you want to build and use DOpE as part of the L4 Environment, you
should check out the required packages from the repository by the following
$ svn checkout -N http://svn.tudos.org/repos/tudos/trunk tudos
$ cd tudos
$ ./repomgr co l4env
$ ./repomgr co dice
$ svn up l4/pkg/dope
The DOpE package will then be located at l4/pkg/dope.
More information about the other needed components are available at the
Norman Feske - email@example.com