1.\" $NetBSD: vchiq.4,v 1.3 2021/12/11 20:42:48 wiz Exp $ 2.\" 3.\" Copyright (c) 2021 The NetBSD Foundation, Inc. 4.\" 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.\" 15.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 16.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 17.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 18.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 19.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 20.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 21.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 22.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 23.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 24.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 25.\" POSSIBILITY OF SUCH DAMAGE. 26.\" 27.Dd December 11, 2021 28.Dt VCHIQ 4 29.Os 30.Sh NAME 31.Nm vchiq 32.Nd Broadcom VideoCore Host Interface device driver 33.Sh SYNOPSIS 34.Cd "vchiq* at simplebus?" 35.Cd "vchiq* at acpi?" 36.Sh DESCRIPTION 37The 38.Nm 39driver provides support for the VideoCore 4 GPU messaging interface in 40Broadcom SoCs found in boards such as the Raspberry Pi. 41.Pp 42Libraries in pkgsrc provide OpenGL ES support and video decoding acceleration 43for the VideoCore 4 using the 44.Pa /dev/vchiq 45interface exposed to userland. 46.Pp 47Audio output support is provided by the kernel through 48.Xr vcaudio 4 , 49which uses this messaging interface to the GPU internally. 50.Pp 51Debugging information may be obtained reading the device with 52.Xr cat 1 . 53eg: 54.Dl cat /dev/vchiq 55.Pp 56Information such as slots and usage by particular functions of the VideoCore 4 57device are displayed. 58.Sh SEE ALSO 59.Xr cat 1 , 60.Xr acpi 4 , 61.Xr bcmgpio 4 , 62.Xr vcaudio 4 , 63.Pa pkgsrc/misc/raspberrypi-userland , 64.Pa pkgsrc/multimedia/omxplayer 65.Sh HISTORY 66The 67.Nm 68device driver appeared in 69.Nx 7.0 . 70.Sh BUGS 71.Pa /dev/vchiq 72does not follow the standard model for graphical acceleration on Unix-like 73systems, so applications have to be specially built to take advantage of it. 74The interface to userland also cannot be exposed by 64-bit or big endian 75kernels due to problems in the upstream Broadcom code. 76