1.\" Copyright (c) 1983, 1991, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 3. All advertising materials mentioning features or use of this software 13.\" must display the following acknowledgement: 14.\" This product includes software developed by the University of 15.\" California, Berkeley and its contributors. 16.\" 4. Neither the name of the University nor the names of its contributors 17.\" may be used to endorse or promote products derived from this software 18.\" without specific prior written permission. 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.\" @(#)ik.4 8.1 (Berkeley) 6/5/93 33.\" 34.Dd June 5, 1993 35.Dt IK 4 vax 36.Os BSD 4.2 37.Sh NAME 38.Nm ik 39.Nd "Ikonas frame buffer, graphics device interface" 40.Sh SYNOPSIS 41.Cd "device ik0 at uba? csr 0172460 vector ikintr" 42.Sh DESCRIPTION 43The 44.Nm ik 45driver 46provides an interface to an Ikonas frame buffer graphics device. 47Each minor device is a different frame buffer interface board. 48When the device is opened, its interface registers are mapped, 49via virtual memory, into the user processes address space. 50This allows the user process very high bandwidth to the frame buffer 51with no system call overhead. 52.Pp 53Bytes written or read from the device are 54.Tn DMA Ns 'ed 55from or to the interface. 56The frame buffer 57.Tn XY 58address, its addressing mode, etc. must be set up by the 59user process before calling write or read. 60.Pp 61Other communication with the driver is via ioctls. 62The 63.Dv IK_GETADDR 64.Xr ioctl 2 65returns the virtual address where the user process can 66find the interface registers. 67The 68.Dv IK_WAITINT 69.Xr ioctl 70suspends the user process until the ikonas device 71has interrupted (for whatever reason \(em the user process has to set 72the interrupt enables). 73.Sh FILES 74.Bl -tag -width /dev/ikxx -compact 75.It Pa /dev/ik 76.El 77.Sh DIAGNOSTICS 78None. 79.Sh HISTORY 80The 81.Nm 82driver appeared in 83.Bx 4.2 . 84.Sh BUGS 85An invalid access (e.g., longword) to a mapped interface register 86can cause the system to crash with a machine check. 87A user process could possibly cause infinite interrupts hence 88bringing things to a crawl. 89