#linuxcnc-devel Logs

Oct 21 2019

01:32 AM memfrob: I spent the last few days separating the musl C library from the RTAI math kernel module and found this was the best solution: https://github.com/NTULINUX/RTAI/commit/74545c65862bee35b21cf89b3de1cdf885b9ddcc
01:36 AM memfrob: I've been trying everything but bringing back the old math code seems the best way to do this without polluting the terminal with harmless warnings about undefined symbols like sin and cos
01:36 AM memfrob: It's not an exact copy of what was done before (RTAI 3 and 4 days) it's been stripped down to just what LinuxCNC needs for math.
01:39 AM memfrob: Whatever you guys think is best to provide LinuxCNC the "sincos" function is fine by me, I now have both approaches ready to go. (modified musl or previous math)
01:41 AM memfrob: Currently, RTAI mainline's approach is sticking the C library in kernel space, while removing certain dangerous functions from it (like memset etc) and exporting the symbols for all the math functions (floor scalbn sin cos sqrt etc) to be used by applications.
01:44 AM memfrob: One more thing, when you build RTAI mainline, you still get 500 warnings about undefined symbols as the linking only occurs after the module is built. You can easily trim these warnings down to about 5 by deleting pretty much everything in export_musl.h except the functions LinuxCNC uses
01:45 AM memfrob: https://github.com/NTULINUX/RTAI/blob/master/src/math/export_musl.h
01:51 AM memfrob: Updated commit: https://github.com/NTULINUX/RTAI/commit/f740779ffec504cadf884d783b74d38d24c6eeb3
01:53 AM memfrob: This RTAI patch would work best with the following change: http://dpaste.com/0T41CQJ
01:59 AM memfrob: Nothing is merged into my master branch on RTAI, this is just a testing playground btw (tiny-math branch) LinuxCNC builds with no undefined symbols in any modules.
02:00 AM memfrob: Night everyone, I'm not on IRC too often so I'll post this info on the mailing list when I get a chance.
06:17 PM andypugh: mozmck: Awake? Where are we with 2.8? Maybe it is time to make a list of things that need doing to make the release happen?
06:21 PM mozmck: hi andypugh, I'm awake. I agree - we should make a list and get the release going. I've been extremely busy again so I haven't had time to look at things much.
06:34 PM andypugh: I have just sent an email to the dev list trying to stimulate some action.
06:35 PM andypugh: Maybe we should decide on a distribution (Debian Buster is probably logical) and try to make preempt-rt and rtai test ISOs?
06:38 PM Tom_L: is buster 10?
06:39 PM andypugh: A friend of mine who is a bit of a Linux expert is messing about with LinuxCNC and Yocto cross compiling. I am not sure if that will ever be relevant, but it would be fun to have him on board. When I say “a bit of a Linux expert” mean that he is a Linux Foundation Fellow.
06:41 PM Tom_L: kind of friends to have
06:48 PM pcw_mesa: Buster seem fine (I'm using Mint19.2 and it based on Buster)
07:06 PM mozmck_lp: pcw_mesa: is that LMDE then? I thought they were discontinuing that.
07:09 PM pcw_mesa: Not sure what LMDE is I, just know Mint 19.2 is based on Ubuntu 18.04 which is based on Buster
07:13 PM mozmck_lp: Ah, I see. I thought it was based on ubuntu 18.04. I didn't know Ubuntu tracked any particular debian release.
07:13 PM mozmck_lp: Linux Mint used to have a version based on debian as well as the normal ones based on Ubuntu, and that one was called LMDE
07:35 PM pcw_mesa: I think a given Ubuntu release may have different debian versions but the one I had been using was based on Buster