|XF86(4)||Device Drivers Manual||XF86(4)|
xf86 — X Window
System aperture driver
On the alpha, amd64, i386, macppc, and sparc64 architectures, the /dev/xf86 driver provides access to the memory and I/O ports of a VGA board and to the PCI configuration registers for use by the X servers when running with a kernel security level greater than 0.
Access to the /dev/xf86 device is allowed when the sysctl(8) variable machdep.allowaperture is greater than or equal to 1. This variable (which has a default value of 0) can only be raised when the security level is less than or equal to 0, so it should be set in /etc/sysctl.conf. The possible values for machdep.allowaperture are:
/dev/xf86 was integrated as an in-kernel device on OpenBSD 2.3. It is required in order to allow access to I/O ports for all X servers since OpenBSD 2.4.
The aperture driver was written by Matthieu Herrb.
This driver allows access to all addresses above physmem. It should be restricted to the actual address range of the video memory.
|May 28, 2015||OpenBSD-5.9|