A little help to finish my hexapod

Hi andypugh
As you have suggested I have looked the source code
github.com/LinuxCNC/linuxcnc/blob/master...ematics/genhexkins.c
and i think a little change of the code can resolve my problem.
So I have installed linuxcnc following this guide: linuxcnc.org/docs/html/getting-started/getting-linuxcnc.html -->7.2. Installing on Ubuntu Precise.

If I compile with
halcompile --install genhexkins.c
I have this error:
/tmp/tmpOdWCxO/genhexkins.c: In function kinematicsForward
/tmp/tmpOdWCxO/genhexkins.c:468:7: error: implicit declaration of function rtapi_fabs [-Werror=implicit-function-declaration]
-- followed by other similar errors --

I think some libraries are not linked correctly. Why?

*************************************************
something else
I also noticed that in the installation procedure it refers to the link
releases.ubuntu.com/precise/
leading to
Ubuntu 12.04.5 LTS (Precise Pangolin)
This installation does not work (i think for a wrong kernel version), it is necessary to use the Ubuntu 12.04 LTS (Precise Pangolin) (version hard to find)

Thanks.

I have reinstalled ubuntu (great fsarchiver), reinstalled LinuxCNC and then copied this 2 files
github.com/LinuxCNC/linuxcnc/blob/master...ematics/genhexkins.c
github.com/LinuxCNC/linuxcnc/blob/master...ematics/genhexkins.h

i have copied genhexkins.h on the /usr/include/linuxcnc/ folder, and now i can compile.

halcompile --install genhexkins.c
make KBUILD_EXTRA_SYMBOLS=/usr/realtime-3.4-9-rtai-686-pae/modules/linuxcnc/Module.symvers -C /usr/src/linux-headers-3.4-9-rtai-686-pae SUBDIRS=`pwd` CC=gcc V=0 modules
make[1]: ingresso nella directory "/usr/src/linux-headers-3.4-9-rtai-686-pae"
CC [M] /tmp/tmpW0KzgX/genhexkins.o
Building modules, stage 2.
MODPOST 1 modules
WARNING: "pmRpyMatConvert" [/tmp/tmpW0KzgX/genhexkins.ko] undefined!
WARNING: "pmCartCartCross" [/tmp/tmpW0KzgX/genhexkins.ko] undefined!
WARNING: "pmCartUnit" [/tmp/tmpW0KzgX/genhexkins.ko] undefined!
WARNING: "pmMatCartMult" [/tmp/tmpW0KzgX/genhexkins.ko] undefined!
WARNING: "pmCartCartAdd" [/tmp/tmpW0KzgX/genhexkins.ko] undefined!
WARNING: "pmCartUnitEq" [/tmp/tmpW0KzgX/genhexkins.ko] undefined!
WARNING: "pmCartCartDot" [/tmp/tmpW0KzgX/genhexkins.ko] undefined!
WARNING: "pmCartMag" [/tmp/tmpW0KzgX/genhexkins.ko] undefined!
WARNING: "pmCartCartSub" [/tmp/tmpW0KzgX/genhexkins.ko] undefined!
CC /tmp/tmpW0KzgX/genhexkins.mod.o
LD [M] /tmp/tmpW0KzgX/genhexkins.ko
make[1]: uscita dalla directory "/usr/src/linux-headers-3.4-9-rtai-686-pae"
cp genhexkins.ko /usr/realtime-3.4-9-rtai-686-pae/modules/linuxcnc/

Now, if i run linuxcnc and select Hexapod this happen
LINUXCNC - 2.7.14
Machine configuration directory is '/usr/share/doc/linuxcnc/examples/sample-configs/sim/axis/vismach/hexapod-sim'
Machine configuration file is 'hexapod.ini'
Starting LinuxCNC...
Found file(REL): ./core_sim_6.hal
insmod: error inserting '/usr/realtime-3.4-9-rtai-686-pae/modules/linuxcnc/genhexkins.ko': -1 Unknown symbol in module
./core_sim_6.hal:4: exit value: 1
./core_sim_6.hal:4: insmod for genhexkins failed, returned -1
See the output of 'dmesg' for more information.
Shutting down and cleaning up LinuxCNC...
LinuxCNC terminated with an error. You can find more information in the log: /home/cnc/linuxcnc_debug.txt
and /home/cnc/linuxcnc_print.txt as well as in the output of the shell command 'dmesg' and in the terminal


this the dmesg report
[ 6503.438802] RTAI[math]: loaded.
[ 6503.471489] genhexkins: Unknown symbol pmCartCartSub (err 0)
[ 6503.471509] genhexkins: Unknown symbol pmCartMag (err 0)
[ 6503.471523] genhexkins: Unknown symbol pmCartCartDot (err 0)
[ 6503.471534] genhexkins: Unknown symbol pmCartUnitEq (err 0)
[ 6503.471545] genhexkins: Unknown symbol pmCartCartAdd (err 0)
[ 6503.471556] genhexkins: Unknown symbol pmMatCartMult (err 0)
[ 6503.471566] genhexkins: Unknown symbol pmCartUnit (err 0)
[ 6503.471577] genhexkins: Unknown symbol pmCartCartCross (err 0)
[ 6503.471586] genhexkins: Unknown symbol pmRpyMatConvert (err 0)
[ 6503.634707] RTAI[math]: unloaded.

I suppose halcompile don't work, WARNING: "pmRpyMatConvert" [/tmp/tmpW0KzgX/genhexkins.ko] undefined! is an error. Is this correct?

Thanks

posemath.h is present and it is on the same folder of genhexkins.h.
I think it is possible to compile genhexkins with halcompile. I have found this post:

forum.linuxcnc.org/forum/10-advanced-con...g-genhexkins?limit=6
I have open posemath.h with gedit and saved it using Unix/Linux line endings, as suggest on the post but I have the same problem.
It seems it is necessary install some packages, but I don't understand which.

linuxcnc-dev is already installed.

sudo apt-get install linuxcnc-dev
[sudo] password for cnc:
Lettura elenco dei pacchetti... Fatto (Read list of packages... Done)
Generazione albero delle dipendenze (Dependency tree generation)
Lettura informazioni sullo stato... Fatto (Reading status information... Done)
linuxcnc-dev è già alla versione più recente (linuxcnc-dev is already at the latest version).

I can't understand...