[warning - esoteric] I had mentioned the confusing situation about kernel versions for the Beaglebone; these are:
1. the TI Arago project (looks sort of official) http://arago-project.org/git/projects/linux-am33x.git 2. the Koen Koi repo on github, 22 branches and 262 tags, zero documentation beyond commit messages 3. the Robert Nelson repo on github, 10 branches 4. The Angström distribution, which holds the kernel with which is distributed with the BB, and of unclear relation to any of the above 5. the vanilla kernel v3.8 merge candidate, which has PRU support included (found on 3) The one we're currently using is based on 1), and on work by Henri Roosen, see the xenomai archives for details. It has support for the Beagleboard, not specifically for the beaglebone though, which was Bas' point. Also I keep looking for alternatives in case something better floats by. It seems I'm not the only one being confused about base versions: A while - a while ago somebody came up with a Beaglebone Xenomai kernel based on 4) : https://github.com/shengchao/beaglebone-angstrom-xenomai/commits/master - today somebody came up with Beaglebone Xenomai kernel based on 2) : http://www.xenomai.org/pipermail/xenomai/2013-January/027568.html I tried to clue up a bit on this mess on the #beagle channel; excerpt below. The takeaway is: - keep fingers off 2) - realistic options for kernel base versions are: 1) (no specific Beaglebone support, based on 3.2, as we have it right now) or 3) the https://github.com/beagleboard/kernel/tree/beaglebone-3.2 as a base for the ipipe 3.2.21 patch NB: it seems nobody has tried this rather obvious option yet - maybe all other options need to be exhausted first. - more theoretic options: 3) https://github.com/beagleboard/kernel/tree/beaglebone-3.6 as a base, and try to forward-port the ipipe 3.5.7 patch - I have no estimate for the effort 3) https://github.com/beagleboard/kernel/tree/3.8 - the merge candidate for mainline linux - again forward-port the ipipe 3.5.7 patch; unknown effort too. In summary: getting Xenomai (or RTAI for that matter, if that happens) to run with the latest and greatest in Beaglebbone peripheral support is hard, and positively outside my range, both of time and clue. I think generally it's advisable not to use hardware-specific features to the greatest extent on these platforms. As far as I'm concerned the PRU support in the current build is fine; maybe the occasional needed feature can be done through a out-of-tree driver. There is a minor improvement conceivable in hardware support with the beaglebone-3.2 base and ipipe 3.2.21 patch applied to it, which might be worth a try. - Michael [5:59pm]mhaberler:hi koen! is there some overview about status of the branches in your repo https://github.com/koenkooi/linux.git ? [6:05pm]koen:mhaberler: yes, all are: don't use [6:06pm]koen:mhaberler: pick a branch from https://github.com/beagleboard/kernel/branches, that is the latest and greatest [6:06pm]mhaberler:I need a 3.2.21 or 3.5.7 base for a xenomai patch [6:16pm]mhaberler:I'm not keen on the kernel branch bingo - so I'd rather ask [6:17pm]mdp:mhaberler: are you wanting to use xenomai on beaglebone? wasn't clear on your platform [6:17pm]mhaberler:yes, actually I have one, although on an arago-3.2 base [6:19pm]mdp:mhaberler: I understand how xenomai's hugely invasive patches land on some magic kernel versions..soo... [6:20pm]mhaberler:mdp: meaning what? [6:20pm]mdp:you have one good choice. you choose the 3.2-ish arago vendor kernel to go with their 3.2 patch [6:21pm]mhaberler:well this is in fact what I did - it lacks on some cape suppport though: http://git.mah.priv.at/gitweb/linuxcnc-kernel.git/shortlog/refs/heads/beaglebone-3.2.21-xenomai-2.6.2 [6:22pm]mdp:mhaberler: your option for proper cape support is to port xenomai 3.5.7 to the 3.8 branch. I can assure you that will suck [6:23pm]mdp:but if you need it, you need it [6:23pm]mdp:that's the price of out-of-tree things like xenomai though [6:23pm]mhaberler:mdp: what about using the https://github.com/beagleboard/kernel/tree/beagleboard-3.5 branch? as a base? makes sense? [6:24pm]mdp:that's beagleboard only [6:24pm]mdp:until you get to the 3.7 branch...all previous versions only work on the named board [6:25pm]mdp:beaglebone-3.6 is the first one for bone [6:25pm]mhaberler:ah [6:25pm]mdp:since 3.2, that is [6:27pm]mhaberler:so it's either beagleboard/beaglebone-3.2 + 3.2.21, or massage xenomai into beagleboard/3.8 ? [6:28pm]mdp:yes [6:28pm]mhaberler:ok, makes sense - thanks a lot [6:28pm]mhaberler:do the koen branches have any bearing on this? [6:29pm]mdp:make sure you check closely in the xenomai community, you may find somebody porting it to the current kernel..I dunno how they pick versions..haven't followed that in some time [6:30pm]mhaberler:I do - today somebody came up with a 3.2.21 Xenomai patched kernel based on some koen linux-ti33x-psp-3.2.21-r13g+gitr720e07b4c1f687b61b147b31c698cb6816d72f01 branch, and I wasnt sure this is a good idea [6:32pm]mhaberler:given that some of that stuff in the base branch doesnt even compile - copy & paste errors - I have some doubts [6:32pm]mdp:it's suboptimal if you need features from 3.8, definitely [6:49pm]mhaberler:mdp: are there any code base differences between the beagleboard/* branches and the Angström distro? sorry if this sounds confused - I am [6:49pm]mdp:mhaberler: nfc how those map [6:49pm]mhaberler:ah. [6:49pm]mhaberler:I feel less alone ------------------------------------------------------------------------------ Everyone hates slow websites. So do we. 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