paul_c at tuxcnc.org
Sun Feb 24 17:52:48 EST 2013
On Sunday 24 February 2013, Federico wrote:
> If you have such a strict timing for an userspace code you should try
> some real-time O.S. Unfortunately the RT_PREEMPT patchset isn't yet
> applicable to current rpi kernel (unless something changed
> The good news it that xenomai seems to be working
> (http://sourceforge.net/p/rtraspberrylinu/blog/) and its even harder
> real-time. In short you run in xenomai the code driving the LEDs and
> in linux the rest of your application. This doesn't come at zero cost
> in terms of time but it should fit your needs.
Raspberry Pi support is now included in Xenomai as a post-patch for
3.5.7 kernels (only available in the git repository at present)-
As long as you use the Posix skin, any code you write now will be
portable across standard Linux, RT_PREEMPT, and Xenomai. The cost is
time in downloading, patching, and compiling a new kernel & libraries,
but this doesn't take long when cross-compiling. The upside (with
Xenomai) is a 30-60uS jitter in scheduling any RT threads.
If you want to go with Xenomai and need any help, drop me a note.
 git clone git://git.xenomai.org/xenomai-head.git xenomai-head
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