Document the SGI mainbus device. With feedback from jmc@.

ok miod@

2 files changed, 46 insertions, 2 deletions

diff --git a/share/man/man4/man4.sgi/Makefile b/share/man/man4/man4.sgi/Makefile
index 05c0c6daad9..8980c87983b 100644
--- a/share/man/man4/man4.sgi/Makefile
+++ b/share/man/man4/man4.sgi/Makefile
@@ -1,6 +1,6 @@
-#	$OpenBSD: Makefile,v 1.7 2007/11/28 14:07:41 jsing Exp $
+#	$OpenBSD: Makefile,v 1.8 2007/11/28 16:27:29 jsing Exp $
 
-MAN=	gbe.4 intro.4 macebus.4 mavb.4 mec.4 mkbc.4
+MAN=	gbe.4 intro.4 macebus.4 mainbus.4 mavb.4 mec.4 mkbc.4
 MLINKS=	macebus.4 macepcibr.4
 MANSUBDIR=sgi
 
diff --git a/share/man/man4/man4.sgi/mainbus.4 b/share/man/man4/man4.sgi/mainbus.4
new file mode 100644
index 00000000000..dc5422d6313
--- /dev/null
+++ b/share/man/man4/man4.sgi/mainbus.4
@@ -0,0 +1,44 @@
+.\"	$OpenBSD: mainbus.4,v 1.1 2007/11/28 16:27:29 jsing Exp $
+.\"
+.\" Copyright (c) 2007 Joel Sing <jsing@openbsd.org>
+.\"
+.\" Permission to use, copy, modify, and distribute this software for any
+.\" purpose with or without fee is hereby granted, provided that the above
+.\" copyright notice and this permission notice appear in all copies.
+.\"
+.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+.\"
+.Dd $Mdocdate: November 28 2007 $
+.Dt MAINBUS 4 sgi
+.Os
+.Sh NAME
+.Nm mainbus
+.Nd SGI main processor bus device
+.Sh SYNOPSIS
+.Cd "mainbus0 at root"
+.Cd "cpu* at mainbus0"
+.Cd "macebus0 at mainbus0"
+.Cd "gbe0 at mainbus0"
+.Sh DESCRIPTION
+The
+.Nm
+interface serves as an abstraction used by the autoconfiguration system to help
+find and attach buses or devices connected to the main processor bus.
+.Pp
+In SGI O2 machines,
+.Nm
+corresponds to the CRIME (CPU, Rendering, Interconnect and Memory Engine) bus
+which acts as a bridge between the CPU, main memory, MACE (Multimedia,
+Audio and Communications Engine) bus, Video Image Compression Engine (VICE)
+and Graphics Back End (GBE).
+.Sh SEE ALSO
+.Xr autoconf 4 ,
+.Xr gbe 4 ,
+.Xr intro 4 ,
+.Xr macebus 4