IO Ports under Unix 386 (ISC, ESIX, SCO & SVR4)

Thomas Roell roell at informatik.tu-muenchen.de
Fri Mar 8 02:36:40 AEST 1991


I have following *little* problem: I want to map some I/O ports into a
application so I don't have to write an extra hardware driver. This is 
primary for performance reasons. "This is simple!",everbody cheers. Just use:

	ioctl("/dev/console", KDENABIO, 1);  /* just symbolically written */

This is true for the ports withing 0x000 - 0x3FF. But the device I have to
deal with is one that also uses other ports (0x9ee8 for ex.). "No problem!", I
hear from some guys with a little more expierence. Just use the following
beast:

	sysi86(SI86V86, V86SC_IOPL, PS_IOPL)

(this allows indeed general io access)

But the IOPL is adjusted every time a signal is recieved by a process. And this
might be in the middle of a io-sequence. Thus this solution is inusable, too.

Now is there a way to get such IOPL with those problems ? 

- Thomas
--
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