> > *That makes sense, but is _way_ beyond the scope of a simple email,* > * particularly since I don't know how much you do or don't know about* > * coding for real-time.* > > *...* > > *Note that Machinekit is a project to control motors and other physical* > * things (ie: machines) that runs under several possible real-time* > * environments (currently Xenomai, PREEMPT_RT, RTAI, and even plain* > * Posix w/o real-time guarantees). The Machinekit images for the BBB* > * are simply a ready-to-run version of the RCN's BBB Debian builds with* > * the Xenomai kernel and Machinekit packages pre-installed for > ease-of-use.*
Thanks Charles. Your answer pretty much answered all my questions. I guess I could have been more succinct in saying that I just wished to know if looking into Xenomai, or machinekit was a waste of time for my own purposes. Which now it does seem that way. For now. Pretty much all I wanted was some form of Linux, that ran on a "tighter schedule". PREEMPT_RT sounds like where I may want to be. I do know a bit about real-time coding, but would definitely not consider myself an expert. In the context of Linux . . . all I know is by reading. No hands on. On Tue, Jun 16, 2015 at 9:19 AM, Charles Steinkuehler < [email protected]> wrote: > On 6/15/2015 4:20 PM, William Hermans wrote: > >> > >> *If you're looking for details on the BBB/Xenomai install, that's not* > >> * really within the realm of the Machinekit docs repo. The best place* > >> * to look for the details and "secret sauce" of building a working > image* > >> * is to actually grab the build scripts from github. Robert Nelson is* > >> * now building the Machinekit images as part of his "universal SoC > build* > >> * farm", so the Machinekit build scripts are right next to (and* > >> * virtually identical to) the scripts used to craft the other > BeagleBone* > >> * images:* > >> > >> * https://github.com/RobertCNelson/omap-image-builder > >> <https://github.com/RobertCNelson/omap-image-builder>* > >> > >> * To make a Machinekit image, just:* > >> > >> * ./RootStock-NG.sh -c machinekit-debian-wheezy* > >> > >> * ...like it says at the bottom of the readme.md <http://readme.md> > file.* > > > > Thanks for your answer Charles. However what I would like to find out is > > how is machinekit different from say Debian. Not so much in difference > > between distro's( because I'm thinking it's "just" a kernel with *some* > > tools ), or determinism, but how does one use it to their full advantage. > > The Machinekit BBB image *IS* Debian, just with a Xenomai capable > kernel and some packages to make use of it pre-installed. > > > So for all I know, one would use it like you'd use Linux in general. My > > guess would be this is not the case however. Also, knowing some > guidelines > > while developing deterministic code would be very handy too. > > > > So basically, stuff that an experienced developer should know when using > > machinekit, but doesn't from lack of experience *with* machinekit. Which > > libc is expected . . . etc. > > > > Does that make any sense ? Maybe I'm looking in the wrong place so far ? > > That makes sense, but is _way_ beyond the scope of a simple email, > particularly since I don't know how much you do or don't know about > coding for real-time. > > If you're wanting to easily write deterministic code, you might want > to use PREEMPT_RT, which works really well on the x86 architecture and > is coming along on the ARM architecture. This allows you to write > "normal" C code, including making kernel syscalls (directly or via > libraries like libc) without loosing real-time performance. > > Xenomai runs in it's own domain, and while you can call routines in > the Linux kernel, doing so breaks any guarantee of hard real-time > performance. So you have to write Xenomai drivers or directly talk to > any hardware you're expecting to have real-time performance. > > Note that Machinekit is a project to control motors and other physical > things (ie: machines) that runs under several possible real-time > environments (currently Xenomai, PREEMPT_RT, RTAI, and even plain > Posix w/o real-time guarantees). The Machinekit images for the BBB > are simply a ready-to-run version of the RCN's BBB Debian builds with > the Xenomai kernel and Machinekit packages pre-installed for ease-of-use. > > -- > Charles Steinkuehler > [email protected] > > -- > For more options, visit http://beagleboard.org/discuss > --- > You received this message because you are subscribed to the Google Groups > "BeagleBoard" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > For more options, visit https://groups.google.com/d/optout. > -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
