Folks,
I have an EPICS application that directly accesses the parallel port
(EPP) registers from user space on Linux. This is to communicate with
an XIA Saturn spectroscopy module.
In order versions of Linux this worked fine if I ran the application as
root, or by calling iopl(3) as root before exec-ing the EPICS application.
I am now trying to run this under a recent Linux (Redhat Fedora) version
baja:~>more /proc/version
Linux version 2.6.26.8-57.fc8 ([email protected])
(gcc version 4.1.2 20070925 (Red Hat 4.1.2-33))
#1 SMP Thu Dec 18 18:59:49 EST 2008
The EPICS IOC now crashes with a segmentation fault when trying to
access the EPP port, even when running as root, and the following entry
appears in /var/log/messages
Jul 9 11:43:44 baja kernel: dxpApp[27837] general protection ip:80a90a6
sp:ff8ea8ac error:0 in dxpApp[8048000+1f7000]
Does anyone know what one needs to do in recent Linux versions to get
access to the IO registers from user-space?
Thanks,
Mark
