MESA 5i25 with non-standard config and modified firmware

I am a novice at LinuxCNC setup trying to build an unusual 4+1 axis machine.
My required configuration is:
4 stepgen axes - X B C W and one stepgen used like a spindle (not in kinematics)

Currently I have:
1. A Mesa 6i25 running modified 5i25 firmware with 7 stepgens
mesaflash --device 5i25 --readhmid - finds card and shows correct stepgens configured
There are no attached breakout boards in this machine.

2. LINUXCNC - 2.9.0~pre
Linux 5.0.21-rt16 #1 SMP PREEMPT RT

3. RIP in ~/linuxcnc-dev
System runs examples like 'configs/sim/axis_9axis.ini' without any problems

4. I used pncconf to create a basic HAL/INI file set for XYZA and a mesa 5i25+7i76x2 -With One 7i76 as a starting point.
After editing the HAL/INI files to have my XBCW axes I selected them in Linuxcnc and get an error:
"Ini variable '[HMOT]CARD0.watchdog.timeout_ns' not found."
CARD0 is set to hm2_5i25.0 in the .ini file.

Looking into src/hal/drivers/mesa-hostmot2 I don't see any driver for 5i25. Do I have to build one? What is the easiest way to get the HAL file to work with this configuration? Can anyone tell me where to go from here?

Omit that line in the ini file and add this line to hal file, after loadrt hm2_pci something or another:
setp hm2_5i25.0.watchdog.timeout_ns 5000000

Thanks, that worked. I don't understand why the variable substitution didn't work.
Now I get a new error at the second ( axis:
pin 'hm2_5i25.0.stepgen.04.dirsetup' not found
This seems to be due to associating B with joint_4. Changing .04.to .01. gets me past this error.
I thought I read in the manual that the joint numbering was fixed as XYXAB... = 01234...

Upload your hal and ini file so we can have a look.
Most probably you missed it while editing.

Here are the files. HAL has Joint_4 changed to joint_1 which fixed the previous error. The settings are just as they came out of PNCconf - I'll worry about that later.

vedatech wrote: Thanks, that worked. I don't understand why the variable substitution didn't work.
Now I get a new error at the second ( B ) axis:
pin 'hm2_5i25.0.stepgen.04.dirsetup' not found
This seems to be due to associating B with joint_4. Changing .04.to .01. gets me past this error.
I thought I read in the manual that the joint numbering was fixed as XYXAB... = 01234...

The error: pin 'hm2_5i25.0.stepgen.04.dirsetup' not found
is expected because:
loadrt hm2_pci config=" num_encoders=0 num_pwmgens=1 num_stepgens=4"
only enables 4 stepgens (0..3)

That helps. Increasing stepgens to 7 fixed the error. Then I increase num_joints=9 which gets rid of errors on all axes except the last one, W, which gives:

hm2_5i25.0.stepgen.08.dirsetup - not found

Any ideas?

Yes, if you set num_stepgens to 7, you will have have 7 stepgens, 0..6

Yes, I so have stepgens 0..6 in the 5i25 card, although only 4 are being used so far.

Right, so any access to a stepgen outside of the range
of 0..6 (like stepgen.08) is an error.

Note that there is no required correspondence at all
between joint #s and stepgen #s, that mapping is up to you...