1.\" $NetBSD: ik.4,v 1.8 2001/08/18 14:37:47 wiz Exp $ 2.\" 3.\" Copyright (c) 1983, 1991, 1993 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. All advertising materials mentioning features or use of this software 15.\" must display the following acknowledgement: 16.\" This product includes software developed by the University of 17.\" California, Berkeley and its contributors. 18.\" 4. Neither the name of the University nor the names of its contributors 19.\" may be used to endorse or promote products derived from this software 20.\" without specific prior written permission. 21.\" 22.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32.\" SUCH DAMAGE. 33.\" 34.\" from: @(#)ik.4 8.1 (Berkeley) 6/5/93 35.\" 36.Dd June 5, 1993 37.Dt IK 4 vax 38.Os 39.Sh NAME 40.Nm ik 41.Nd Ikonas frame buffer, graphics device interface 42.Sh SYNOPSIS 43.Cd "ik0 at uba? csr 0172460 vector ikintr" 44.Sh DESCRIPTION 45NOTE: This driver has not been ported from 46.Bx 4.4 47yet. 48.Pp 49The 50.Nm ik 51driver 52provides an interface to an Ikonas frame buffer graphics device. 53Each minor device is a different frame buffer interface board. 54When the device is opened, its interface registers are mapped, 55via virtual memory, into the user processes address space. 56This allows the user process very high bandwidth to the frame buffer 57with no system call overhead. 58.Pp 59Bytes written or read from the device are 60.Tn DMA Ns 'ed 61from or to the interface. 62The frame buffer 63.Tn XY 64address, its addressing mode, etc. must be set up by the 65user process before calling write or read. 66.Pp 67Other communication with the driver is via ioctls. 68The 69.Dv IK_GETADDR 70.Xr ioctl 2 71returns the virtual address where the user process can 72find the interface registers. 73The 74.Dv IK_WAITINT 75.Xr ioctl 2 76suspends the user process until the ikonas device 77has interrupted (for whatever reason \(em the user process has to set 78the interrupt enables). 79.Sh FILES 80.Bl -tag -width /dev/ikxx -compact 81.It Pa /dev/ik 82.El 83.Sh DIAGNOSTICS 84None. 85.Sh HISTORY 86The 87.Nm 88driver appeared in 89.Bx 4.2 . 90.Sh BUGS 91An invalid access (e.g., longword) to a mapped interface register 92can cause the system to crash with a machine check. 93A user process could possibly cause infinite interrupts hence 94bringing things to a crawl. 95