JAVA-BASED REAL-TIME PROGRAMMING

• Each piece of software must be written such that it runs on both standard
desktop computers such as Windows and Linux, as well as on existing
and future embedded platforms. A combination of Java and C,
supporting libraries, and multiple models of execution is then needed.
• Apart from device drivers that need to be system specific, software needs
to be written such that it works concurrently correctly and with appropriate
aware timing on the desktop OS, while providing real-time
guarantees when run on a real-time OS.
• Real-time requirements should be expressed, and possible to express, in
the software. Real-time programming is the 'art' of how to do that.
Real-time systems are traditionally built by developing concurrent software,
which is then deployed on a real-time platform. The real-time
demands can then be fulfilled, but only with extra engineering for each
new type of system. That is in many cases not an option, due to market
opportunities or since systems may need to be reconfigured "on the field"
to unforeseen configurations.
• The wide-spread use of programmable devices, or devices including embedded
software that may need frequent customization, calls for “technically
generally useful” software tools 5 and platforms, and free software.
The platform must permit specific applications built on top of it to be
proprietary and closed, to protect business-critical know-how (software
patent do not work).
In parallel with this document, free software tools are being developed and
made available on the Internet, by our group and due to other efforts. Commercial
software can then be developed for specific applications and systems,
and since such software is not “technically generally useful” they may very
well be proprietary. Still, the technology, library and tools presented here
may be used free of charge(even commercially), but additions and changes
must remain free (GNU LGPL).
Note: This document still contains material from other sources without
proper references; this will be taken care of before official release. Details of
the licenses from Sun Microsystems are also under detailed reviewing.
History
To be written (referring to the LTH research in robotics and embedded realtime
systems, and to the developments for the EDA040 course).
This section is subject to special conditions in the GNU license terms.
5 That in turn, as expressed by Richard Stallman (the founder of GNU), implies that
such software (but not the applications using it) must be free.
4 2012-08-29 16:05