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Linux Gains Native RTOS Emulation Layer
nerdyH writes to tell us that the Xenomai/SOLO project is attempting to deliver VxWorks and other RTOS emulation for any Linux kernel. "Some weeks ago, I started laying the groundwork for porting the Xenomai emulators natively over the PREEMPT_RT kernel. Unlike the co-kernel based Xenomai version, SOLO does not require any kernel support from additional modules or patches. It is fully based on the standard POSIX library, and runs as a regular process controlled by a single image Linux kernel. As a first step, a VxWorks emulator has just been rebuilt over this new framework."
FFS don't click that link - it's some sort of browser spawner/malware/virus.
.exe - luckily on my mac that did nothing.. that's the virus payload I guess
I had to power cycle my machine to shut it down as it managed to completely saturate the machine.
As far as I can tell it:
1. Tried to log me onto a gay porn site
2. Tried to open up IRC and do something (failed, luckily, since osx won't let such things happen automatically.. my screen just filled boxes asking if I wanted to start colloquy)
3. Tried to run a
I reckon if you clicked that button on a windows machine you'd be crying right now - and your passwords would be all over IRC too...
The problem with VxWorks is that the scheduling accuracy is its only positive feature. Device drivers are rare and expensive, probably because it doesn't have a sensible hardware abstraction layer like Linux, Windows (NT family), and QNX. If you want to use the MMU on the processor you get charged again, and you get even more incompatibilities. The documentation doesn't go into much depth, and Google isn't very helpful, as hardly anybody talks about it on the Internet.
Have you tried QNX or RTEMS? I don't have any data on their scheduling accuracy, but they claim to support the same real-time features. I've also found the QNX documentation much easier to follow, and I managed to turn out a BSP and a custom device driver within a week of first receiving the software.
RTEMS is a free, open source alternative to VxWorks that provides POSIX threads in addition to an API we call the "Classic API" that was based upon an old dead proposed VITA standard from pSOS+ folks. RTEMS is single process, multi-threaded in the POSIX sense and has almost every POSIX 1003.1b features that is possible without being able to exec a new process. We use GNU tools and maintain an APT/Yum repository so GNU/Linux users have an easy situation with the tools. Check out some of the places it has been used at http://www.rtems.org/flyers.html and in the Wiki Applications page. You can get predictable tasking and algorithmic behavior while still staying in the free software world.
I don't think you should be speaking against RTOS without any actual RTOS experience. It just makes everyone else assume you're an ass.
These things typically run on embedded devices, not a friggin' Dell midtower. They do one job and they do it with exacting accuracy, on minified motherboards and fanless CPUs, hooked up to custom-built controllers and monitoring equipment.
RTOS tasks are typically things we used to do in solid state with simple feedback logic, but the RTOS allows it to be done in software at a lower cost, plus allowing easy updates or adjustments without a complete redesign.
-Billco, Fnarg.com