Re: Question: module_types.h

[hill@luke.atdiv.lanl.gov (Jeff Hill)]

> 
> 	I'm in the process of trying to add a VME driver to module_types.h
> and seem to be running into problems. Can anyone tell me where to look for the
> definitions of MT_DEF_PARM and MODULE_TYPES_INIT?  

The C macro MODULE_TYPES_DEF facilitates the inclusion of module_types.h
into many source modules without allocating storage for the variables
declared within in all of these modules. The parameter MODULE_TYPES_INIT
is defined in the single source module that allocates storage for the
parameters. 

MT_DEF_PARM is a parameter to the macro MODULE_TYPES_DEF(MT_DEF_PARM)
which is defined in module_types.h.

For example the definition:

#define MODULE_TYPES_DEF(MT_DEF_PARM) extern MT_DEF_PARM;
MODULE_TYPES_DEF(short ai_num_cards[MAX_AI_TYPES+1])

results in:

extern short ai_num_cards[MAX_AI_TYPES+1];

> I'm having problems adding a
> 13th module. I add the appropriate information to the ai lists (address, number
> of cards, etc...), but it seems to ignore it and instead set the value to the
> first entry in the successive list.  (and yes, MAX_AI_TYPES is set correctly
> 

Most likely your problem results from share/src/db/iocInit.c
needing to be recompiled. This is the one module
that defines MODULE_TYPES_INIT.

It is also possible to modify __existing__ parameters by making 
changes to a private copy of share/src/drv/module_types.c.
Recompile this module and reload it after you load iocCore. Next, call
the module_types() entry point from the vxWorks shell just prior to calling 
iocInit from the shell (module_types() isnt called by iocInit).

I will add a short section on this source of confusion to the 
"writing a device driver" notes that I am preparing.

Jeff


______________________________________________________________________
Jeffrey O. Hill			Internet	johill@lanl.gov
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