External interfacing/freqmod.o problems

[John Murphy <john-at-wyosip.com>]

I'm using the latest CVS version of EMC on redhad 6.0.  It built
normally and starts up in the non-sim mode, but now I'm trying to
interface it to custom hardware...

I have defined a dispatcher, and given it functions that work
on my own hardware.  I modifed the emcmot Makefile such that
the freqmod module now includes my dispatcher instead of the
parallel port (I'm using a digital I/O card and a custom encoder
feedback card).  

I'm able to get the new "freqmod" to compile, and modify the ini file to
use the new module.  

When I start up emc, I get the following undefined symbols:

 
Current platform is linux_2_2_14
Current real-time platform is rtlinux_2_2
inivar = plat/linux_2_2_14/bin/inivar
INIFILE = grizzly.ini
starting emc...
starting EMC MOTION PROGRAM --
freqmod.o...plat/rtlinux_2_2/lib/freqmod.o: unresolved symbol
get_pte_kernel_slow
plat/rtlinux_2_2/lib/freqmod.o: unresolved symbol get_pte_slow
plat/rtlinux_2_2/lib/freqmod.o: unresolved symbol __bad_pte
plat/rtlinux_2_2/lib/freqmod.o: unresolved symbol __bad_pte_kernel
plat/rtlinux_2_2/lib/freqmod.o: unresolved symbol
__this_fixmap_does_not_exist
can't install it
                 

I'm using red hat 6.0 with RTLinux 2.2.  Things seem to be working for
the
most part, but broke when I started adding my hardware.

Some questions about adding hardware:

1) What controls which digital IO pins are used for stepper signals? 
Will the
stepper system use my extDioWrite to control steppers on digital
i/o pins matching indices 0..5  ??


2)Is there an easy way to enable/disable encoder feedback?  I'd like to
initially
just run "open loop stepper" and watch the encoder counts, without EMC
complaining about the encoder not following, since initially the
mechanical
system does not have the two coupled.  Turning the encoders off would be
OK.

3) Exactly how should the encoder functions be reporting position?  My
encoder counter hardware counts 800 counts/rev, but will wrap at 16
bits.
Do I need to implement software to catch and hide this wrap assuming
periodic execution at high enough rate to see the wrap, or does EMC have
some way of handling this.

Thanks,
John Murphy