Privileged instructions with Fusion

Philippe Gerum rpm at
Mon Oct 18 11:44:22 CEST 2004

On Mon, 2004-10-18 at 10:47, Hans-Jürgen Ude wrote:
> I've just started to try RTAI/Fusion. I've got it installed and running. The 
> testsuite samples work too. Then I've just put an outb() function into one 
> thread to watch the timing with an oscilloscope on LPT. As expected this 
> doesn't work. Inline assebmly doesn't work either. It prompts "Killed" and 
> terminates. So my question is how can I get this to work without using 
> ioperm() or iopl(). Later on I'll need some direct memory access too. 
> Otherwise i'd  have to write a complete PCI driver for proprietary hardware, 
> but i've never done that before.

Fusion sets CAP_SYS_RAWIO for the real-time threads, allowing further
use of ioperm()/iopl(). Is there any reason for not calling them in your

> TIA,
> Hans
> _______________________________________________
> RTAI mailing list
> RTAI at


More information about the Rtai mailing list