Advice on high mem ioports needed

[Gene Heskett]

Greetings;

I'm trying to cobble up a kernel driver for a card with 3 each
8255's on it, to be used as machine control.

I have supposedly modified it for the 4 byte jumps this card uses
between port addresses, and the compile and insmod both seem
to work w/o errors when the insmod is given the argument of
io=0xf100 (where the cards address is set to via dipswitches) as
long as I don't try to register more than the first of 3 chips on
this board.

But, running a demo program using port_a  of chip 0 thats supposed
to cause a motor to step once per second has no effect on the 8255 in
question, while a reboot to dos, and a dos based exersize program
works just fine.

I think the code I'm fooling with (google for PIO-tar.gz) assumes
its working below the 0x3FF barrier, but this card responds to
accesses in the 0xF100-0xF12F range.  I *think* this might be my
problem..

I've looked up the iopl call, but so far no "blinding flash of
knowledge" has come my way.  Is there a resource available that can
enlighten me on this subject?  Something that starts at square one
as I'm a total dummy vis-a-vis pci bus management functions.

The kernel running is the one from emc's Brain Dead Install, 
version rc46, kernel=2.4.25-adeos, so the advice should be valid
for later 2.4 kernels as I've been told that the 2.6 stuff has a whole 
new api.

Thanks for any pointers that can be thrown my way.

-- 
Cheers, Gene
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
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Yahoo.com attorneys please note, additions to this message
by Gene Heskett are:
Copyright 2004 by Maurice Eugene Heskett, all rights reserved.

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