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Papers On Real-Time And Embedded Linux

Posted by Zonk on from the embedded-where dept.

An anonymous reader writes "LinuxDevices has once again published the proceedings of the annual Real-Time Linux Workshop. This one, the seventh, was held in France earlier this month, at the University for Science and Technology of Lille (USTL). The papers span a range of topics, from fundamental real-time technologies to applications, hardware, and tools. Enjoy!"

8 of 102 comments (clear)

  1. Re:what about a complete embedded linux distributi by Jerry+Coffin · · Score: 5, Informative
    what about a complete embedded linux distribution for x86. Just think how much faster your system would become.

    This has already been modded as a troll, but giving you the benefit of the doubt, do you mean something different from things like Monta Vista or Lynuxworks ?

    Of course, it's also worth mentioning that "real time" doesn't necessarily mean "fast." In fact, rather the opposite is typically true: a real-time system must (by nature) make the worst case predictable -- but often compromises the average performance to do so.

    --
    The universe is a figment of its own imagination.

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    The universe is a figment of its own imagination.
  2. not really key area for linux by Keruo · · Score: 4, Informative

    Embedded devices aren't really focus market for linux. Even with being stripped to bare minimum, the kernel will take over 500kb to operate.
    Embedded systems usually don't have need to carry that much memory. Task specific operating systems like TRON and its variations take only few kilobytes, and are extremely efficient and reliable in what they do.
    What linux provides, is interesting approach, but it also rises the price tag with hardware specs higher than the cheapest alternatives.

    --
    There are no atheists when recovering from tape backup.
    1. Re:not really key area for linux by gnalre · · Score: 2, Informative

      The term embedded covers a large area from small devices to devices with more power than desk top machines.

      However in the latest ESP survey it was found 24% said they were using linux 17% said they were likely to use it soon and 33% said it was likiely they would use it. That shows that Nearly 75% with an interest in linux. Not bad fo a non focussed market.

      ALso the biggest embedded OS provider(vxworks 22%) are pushing linux hard as a complementry solution to there flagship product.

      So I would say linux has a big future in the embedded world

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  3. Real-time java? Talk about your oxymorons by ClosedSource · · Score: 2, Informative

    Real-time software isn't even necessarily processor speed-independent, let alone platform dependent.

    In the worst case, you have to know exactly how many time (accurate to the length of a CPU cycle) it will take for a section of code to be executed or know exactly how long it will take an interrupt to vector to your interrupt handler.

    I'll be Java timing isn't even consistent from one JVM release to the next for the same code running on the same computer.

    1. Re:Real-time java? Talk about your oxymorons by Hast · · Score: 2, Informative

      How about if you try to look into facts before shooting your mouth off?

      While Java and real-time may seem like hard to integrate it is possible and it has been done (successfully). Eg I've seen demonstrations of RT systems runnning on industrial robots which balanced inverted pendulums without a problem.

      Now naturally timing may differ between architectures, that's to be expected. What's important is that if you have a specific architecture you need to know, exactly, what delays occur and that they have upper bounds. The same would be true with a Asm or C RT system.

      The main reason you'd want to run Java RT is because first off, it's faster to write correctly. It also makes it possible to have eg dynamic reprogramming on a factory floor. (To the point where new control data is updated while the welder robot switches between weld spots.)

  4. Re:Amazing Field of Work by Quirk · · Score: 2, Informative

    Not my bailiwick, but isn't ITRON meant to be the best embedded systems OS?

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  5. Re:Good Books on the Subject by Doppler00 · · Score: 2, Informative

    Not only did you not recommend any books you didn't even spell embedded right.

    For the most part I think you'll learn the most just reading through the databooks and application notes that come with the particular embedded platform that you are working on. Stay FAR away from any hobby-type embedded systems books that focus on PIC processors if you are doing anything serious. I've found a lot of the code in those types of books to be poorly written and counter productive. Since most embedded systems are programmed in C you'll want to pick up a book on that.

  6. Re:Wow, I'm Impressed? by Animats · · Score: 2, Informative
    AFAIK, device drivers are in kernel space in QNX

    No, device drivers in QNX are in 100% in user space. I've written one, for FireWire cameras. Manual page here.

    QNX device drivers can have the privilege of mapping device memory into their address space, but they're still user-level programs. I've developed hardware drivers on a running QNX system without rebooting.