Experimental Physics and
Industrial Control System

John Quintana <[email protected]> · Tue, 26 Jun 2001 23:29:10 -0500 (CDT)

On Tue, 26 Jun 2001, Eric Norum wrote:

> Bill Lavender wrote:
> .
> .
> .
> > Can you send me a copy of the changes that you had to make to talk to the
> > Cyberresearch boards?  It would be useful to see some examples of what is
> > required to talk to real devices under Linux via ioccore.
>
> For simple I/O (no interrupts, no DMA) I've found it easiest to just use
> inb, outb, etc. right from the user level.  No kernel modules and no
> linux drivers required.  I start such applications from a setuid-root
> wrapper which allocates the appropriate I/O ports then setuid's back to
> the real uid and exec's the application.  In this way any user can
> safely play with the device without needing root priviliges.
>
>

Yep, that is what I am doing now.  Very simple using inb and outb.
The only real "issue" is the compile time -ansi -pedantic which
breaks the macros in /usr/include/asm/io.h, but I was lazy and just
wrote a simple wrapper library. for this.  Its cleaner in ioccore
since that app can run as root so an iopl(3) does it all.

- John

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John Quintana                       Phone:630-252-0221
Northwestern University             FAX: 630-252-0226
DND-CAT                             email: [email protected]
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Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System