#linuxcnc-devel | Logs for 2015-03-15

[01:20:41] <memfrob> One of the new features of RTAI (that I haven't gotten working yet) is an at-compile-time x86 latency calibration tool, and it adjusts RTAI to fit that system's timer, I don't know the full details but I believe it's supposed to lower latency dramatically on systems tuned for it.
[01:21:37] <memfrob> I sent a few emails out to the RTAI mailing list and I'm waiting on a potentional fix or at least some more info on why it's not working.
[04:50:37] <mariusl> G'day All. Has anyone here configured the 7i80 on debian and mafe it work. I am looking for a sample config
[07:40:37] <ketul> I am interested for New realtime kernels in LinuxCNC
[07:40:46] <ketul> can anyone help for getting started
[07:48:37] <archivist> your project, you need to decide
[07:50:58] <archivist> have you looked at any linuxcnc documentation yet etc
[08:09:47] <ketul> yep archivist
[08:09:54] <ketul> I have seen it
[08:10:18] <ketul> and I cross compiled vanilla kernel for BBB also
[08:11:52] <ketul> So tell me any requirements from your side ?
[08:12:26] <ketul> Or I have to directly apply through melange?
[08:13:05] <archivist> no idea I am not a mentor
[08:13:29] <ketul> ok thats why I was asking about mentor on #brlcad
[08:14:12] <archivist> you needed the real question which you have only just alluded to
[08:14:20] <ketul> also mailed to Sebastian Kuzminsky. But no response
[08:14:55] <archivist> everyone are volunteers, you need to wait for answers
[08:15:04] <ketul> ok
[08:48:13] <CaptHindsight> ketul: new RTAI, preempr_rt or?
[09:35:57] <ketul> CaptHindsight: yes
[09:36:49] <archivist> yes what
[09:38:02] <archivist> ketul, this line was in Sean's message to gsoc students on the brlcad mailing list "If this were a college homework assignment, think of your ability to communicate well as being worth half your grade! The other half is how productive you can be without unnecessarily consuming the time of others."
[09:39:43] <ketul> LinuxCNC supports two realtime kernels: RTAI and Preempt-RT. I didn't get "or"
[09:40:22] <archivist> there are other kernels you could be writing another
[09:41:29] <ketul> LinuxCNC supports two realtime kernels: RTAI and Preempt-RT. We target a variety of Debian-based distributions, and we provide debian packages of the realtime kernels we need. The goal of this project is to expand existing packaging infrastructure to build newer versions of RTAI and Preempt-RT, for Debian Jessie and Ubuntu Trusty.
[09:41:38] <ketul> this is the project idea right.
[09:42:37] <ketul> so here the idea is not about other kernels
[09:43:03] <pcw_home> Yeah
[09:47:15] <ketul> archivist: Now tell me what I am supposed to do?
[09:49:37] <archivist> I think some self driving is required, I would have to google to tell you
[09:52:20] <pcw_home> Have you built real time kernels before?
[09:52:22] <pcw_home> (RTAI is more trouble than Preemt-RT but typically has better performance)
[10:05:51] <ketul> pcw_yes
[10:06:01] <ketul> I have build rtems too.
[10:06:05] <ketul> nd vanilla
[10:06:23] <ketul> pcw_home *
[10:13:30] <seb_kuzminsky> ketul: hi
[10:14:16] <seb_kuzminsky> you're right, the project as i wrote it down is: update our kernel packaging for rtai and rt-preempt
[10:15:58] <ketul> seb_kuzminsky: hi
[10:16:07] <seb_kuzminsky> for getting started, you've done the first step, which is to come talk to us
[10:16:16] <ketul> I mailed you .
[10:16:45] <seb_kuzminsky> the next step will be to check out the existing kernel packaging infrastructure, it's not super simple
[10:16:45] <ketul> ok then what am I supposed to be?
[10:17:02] <seb_kuzminsky> i saw your email, sorry i didnt reply sooner
[10:17:12] <ketul> np.
[10:18:01] <seb_kuzminsky> where are you from? what is your interest in linuxcnc and/or realtime kernels?
[10:18:24] <ketul> you mean stream?
[10:18:40] <ketul> Electronics and Communication
[10:20:24] <ketul> My interest is in embedded systems and know the basics about that
[10:20:57] <ketul> I do have worked with 3d printer
[10:21:03] <seb_kuzminsky> cool
[10:21:16] <seb_kuzminsky> have you used debian long?
[10:21:27] <ketul> yep
[10:21:36] <seb_kuzminsky> have you build debian packages before?
[10:21:36] <ketul> in beagle also
[10:22:27] <seb_kuzminsky> cool, we dont support on the beaglebone currently, but one possible outcome of this gsoc project would be a usable rt-preempt kernel for the bbb, and then linuxcnc could run on it
[10:23:57] <ketul> In that mail I wrote my github link about rt kernel build
[10:24:07] <ketul> :)
[10:24:28] <seb_kuzminsky> aha, i should read it
[10:24:31] * seb_kuzminsky reads
[10:24:38] <ketul> (y)
[10:25:20] <seb_kuzminsky> oh yeah, you sent it yesterday morning, it's not unusual for me to take a couple of days to respond to email unforunately
[10:25:40] <ketul> cool, ya its ok
[10:27:40] <ketul> actually currently working on UAV having Nuttx RTOS
[10:28:12] <seb_kuzminsky> ok cool, so you forked vmayoral's bbb build system and figured out how to run it, and documented the process
[10:28:17] <seb_kuzminsky> that's a great start
[10:28:48] <seb_kuzminsky> the build system we use is quite different, it's based on the debian.org packaging of the linux kernel
[10:29:01] <seb_kuzminsky> with a custom pbuilder-based build system wrapped around it
[10:29:19] <ketul> ok
[10:29:58] <ketul> so which kind of documents should I read for that
[10:30:01] <seb_kuzminsky> the next step is probably to clone the linux-rtai-build repo locally and try to build it
[10:30:15] <ketul> ok
[10:30:15] <pcw_home> also a bit different than embedded systems because 1 kernel needs to support a wide variety of hardware
[10:30:17] <seb_kuzminsky> the top-level README in that repo has all the docs we have about kernel building
[10:30:17] <pcw_home> (and how wide is an interesting choice)
[10:30:42] <seb_kuzminsky> pcw_home: yeah, good point
[10:30:57] <seb_kuzminsky> we get a lot of that by piggybacking on debian.org's kernel configs
[10:31:35] <ketul> ok
[10:31:45] <seb_kuzminsky> they have three x86 kernel configs, we build & ship two of them: 686-pae (32-bit) and amd64 (64-bit)
[10:32:14] <ketul> yep
[10:32:31] <seb_kuzminsky> we do not currently deal with their non-pae i486 flavor for ancient computers
[10:32:52] <seb_kuzminsky> it could be added, but i dont think it adds much value
[10:33:44] <seb_kuzminsky> the main thing we change is add what debian calls a patchset, containing one of memfrob's rtai patches
[10:35:04] <seb_kuzminsky> in addition to the rtai kernel that linuxcnc.org publishes, linuxcnc supports (can run under) the rt-preempt kernel that debian.org ships for wheezy (debian 7)
[10:35:49] <seb_kuzminsky> they ship that kernel for i686-pae and amd64 (and notably not for arm)
[10:36:07] <seb_kuzminsky> so, i have three goals for this gsoc project:
[10:36:27] <seb_kuzminsky> 1. update our rtai kernel (for 686-pae and amd64) to a newer version of linux & rtai
[10:36:59] <seb_kuzminsky> 2. debian.org dropped their preempt-rt kernel for jessie, we should pick it up (update to a newer version of linux & preempt-rt)
[10:37:08] <ketul> ok
[10:37:31] <seb_kuzminsky> 3. (stretch goal) build a preempt-rt kernel for some set of arm boards (bbb & u3 maybe?)
[10:37:57] <pcw_home> Jetson?
[10:38:30] <seb_kuzminsky> yeah, that's a good one
[10:38:55] <seb_kuzminsky> might work well with hm2 spi or eth
[10:39:21] <seb_kuzminsky> ketul: there's another student named shivam, who's also expressed interest in working on this project
[10:39:35] <seb_kuzminsky> we'll have to figure out how that works (this is my first year as a gsoc mentor)
[10:39:37] <ketul> ok cool
[10:40:26] <seb_kuzminsky> so for now i suggest you try to reproduce the linux-rtai-build build, and ask here or mail the emc-developers list with any questions
[10:41:59] <ketul> just want to tell you that as far as your repo linux-rtai-build is concerned I am the first 1 for fork. means 1 forks yet.
[10:43:13] <ketul> cool
[10:46:31] <pcw_home> seb_kuzminsky: isn't probe-parport is gone as of 2.7?
[10:46:46] <seb_kuzminsky> yes
[10:47:03] <pcw_home> (forum question)
[10:47:24] <seb_kuzminsky> http://linuxcnc.org/docs/2.7/html/getting-started/index.html#_updating_your_config
[11:46:50] <memfrob> ketul: Didn't read all of the scrollback but if you want new RTAI code I'm actually in the midst of re-writing RTAI 4.1 with kernel 3.16.7 support and removing all the in-kernel legacy RT code (legacy interface to IPIPE)
[11:47:39] <memfrob> as of right now though in terms of stable, there is the master branch of my RTAI tree hosted at github.com/NTULINUX/RTAI
[11:48:22] <memfrob> dev tree has the latest 4.1 and additional odds and ends but does not work yet and does not have updated kernel patches
[11:48:25] <ketul> ok let me check
[11:49:04] <memfrob> master branch is rock solid and specifically tuned for linuxcnc, tested on 32 and 64-bit systems, latest kernel supported is 3.16.7
[11:50:43] <memfrob> speaking of dev tree, I got the rtai_sched module loaded before rtai_fifos but I'm running into a really serious problem which I think has to do with the re-write self. waiting for lat to become ready... (hangs here forever) mouse locks up, and kernel eventually freezes
[11:54:32] <memfrob> Also when I run halrun -U for some reason it says cannot access shared memory errno=19
[11:54:57] <memfrob> /etc/security/limits.conf has the memlock stuff in there but it still has issues
[11:57:32] <ketul> memfrob: sorry missed last lines can you please copy paste?
[11:57:53] <memfrob> the lines after let me check?
[11:58:36] <memfrob> master branch is rock solid and specifically tuned for linuxcnc, tested on 32 and 64-bit systems, latest kernel supported is 3.16.7
[11:58:47] <ketul> ok got
[11:58:59] <ketul> seb_kuzminsky: done built
[11:59:05] <memfrob> the rest of what i said was just about the problems I'm having with dev branch
[11:59:23] <memfrob> Hmm.. where is jepler?
[12:00:34] <memfrob> A few months back he proposed the idea of an RTAPI that has a direct interface to IPIPE, now that I'm re-writing RTAI a third time and the problems I'm having, I really wish I supported his idea.
[12:01:17] <memfrob> a RTAPI -> IPIPE without xenomai / rtai would really make things easy.
[12:03:09] <CaptHindsight> a concern the devs here might have is long term support for this vs rolling the dice with RTAI.org
[12:50:59] <ketul> seb_kuzminsky: reproduced successfully.
[12:51:33] <ketul> :)
[13:25:58] <seb_kuzminsky> ketul: great! did you build both linux-image-rtai and rtai-modules? link to your deb archive pls
[13:31:35] <ketul> its same as your repo
[13:32:12] <ketul> rtai modules remaining I think
[13:32:40] <memfrob> my repo?
[13:33:06] <ketul> last line "touch stamps/precise/i386/kernel-wedge.deb"
[13:33:20] <memfrob> ah, not my repo.
[13:33:57] <ketul> yep memfrob. actually +seb_kuzminsky told me to do so.
[13:34:57] <ketul> :)
[13:35:20] <memfrob> my repo has nothing to do with seb's work just FYI
[13:39:40] <memfrob> wait, seb_kuzminsky, which one of my patches did you include?
[13:39:52] <ketul> cool
[13:40:02] <memfrob> i'm so confused!
[13:40:22] <ketul> me too .
[13:41:07] <memfrob> heh.
[13:42:21] <ketul> actually I am interested for project called New realtime kernels (mentor is seb_kuzminsky)
[13:43:51] <memfrob> IPIPE (the RT kernel code used by xenomai and RTAI) only goes up to 3.16 but i was able to bump it to 3.16.7, 3.18 is in development though
[13:44:33] <memfrob> http://git.xenomai.org/ipipe.git/
[13:44:54] <memfrob> When 3.18 is stable I'll throw it into RTAI
[13:51:44] <memfrob> probably master branch as the dev branch might be broken for quite some time
[14:25:21] <seb_kuzminsky> memfrob: ketul is reproducing the steps that i took to build our kernel & rtai debs, as an introduction to the build system, so that he can update it to a new kernel & rtai version in the future
[14:26:36] <seb_kuzminsky> it's using your hal-linux-3.4.55-x86-1.patch
[14:26:58] <seb_kuzminsky> from commit a0dc5355 of the Shabby RTAI repo
[14:27:50] <seb_kuzminsky> ketul: when i asked for a link to the deb archive, i meant the debian packages that you built using that build system.
[14:28:21] <seb_kuzminsky> they show up in "dists/", in the top-level directory of the linux-rtai-build checkout
[14:41:21] <ketul> seb_kuzminsky: I built debian package for amd64 and i386 right.
[14:43:07] <ketul> I got that in /dists/precise/main
[14:46:40] <ketul> sorry let me do some changes
[16:15:28] <KimK_laptop> skunkworks: Hi Sam. I recall your interest in engines. Have you seen this piston & connecting rod animation done with FreeCAD? http://giant.gfycat.com/EntireUnimportantIndianpangolin.gif Details here: http://freecad-tutorial.blogspot.com/2014/06/piston-conrod-animation.html
[19:09:21] <memfrob> seb_kuzminsky: oh that commit, i thought it was a commit from my master NTULINUX branch