1.\" $OpenBSD: mainbus.4,v 1.2 2007/05/31 19:19:50 jmc Exp $ 2.\" 3.\" Copyright (c) 2006 Jason McIntyre <jmc@openbsd.org> 4.\" 5.\" Permission to use, copy, modify, and distribute this software for any 6.\" purpose with or without fee is hereby granted, provided that the above 7.\" copyright notice and this permission notice appear in all copies. 8.\" 9.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 10.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 11.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 12.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 13.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 14.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 15.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 16.\" 17.Dd $Mdocdate: May 31 2007 $ 18.Dt MAINBUS 4 19.Os 20.Sh NAME 21.Nm mainbus 22.Nd device tree root 23.Sh SYNOPSIS 24.Cd "mainbus0 at root" 25.Sh DESCRIPTION 26.Nm 27provides an abstraction for all system buses to attach to. 28It is the start of the device tree and always attached. 29It is not a physical device as such, 30but an abstraction to which other devices may attach. 31.Pp 32The actual buses which attach are largely machine-dependent; 33refer to the individual man pages for more information. 34.Sh SEE ALSO 35.Xr autoconf 4 , 36.Xr intro 4 37