.\"	$NetBSD: ibus.4,v 1.7 2017/07/25 08:30:45 wiz Exp $
.\"
.\" Copyright (c) 1998 MINOURA Makoto
.\" Copyright (c) 1998 NetBSD Foundation, Inc.
.\" All rights reserved.
.\"
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.\" modification, are permitted provided that the following conditions
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.\" 2. Redistributions in binary form must reproduce the above copyright
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.\" 3. All advertising materials mentioning features or use of this software
.\"    must display the following acknowledgement:
.\"    This product includes software developed by Minoura Makoto.
.\" 4. The name of the author may not be used to endorse or promote products
.\"    derived from this software without specific prior written permission
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.Dd February 17, 2017
.Dt IBUS 4 pmax
.Os
.Sh NAME
.Nm ibus
.Nd pmax internal I/O space driver
.Sh SYNOPSIS
.Cd "ibus0 at mainbus0"
.Cd "ibus0 at tc? slot ? offset ?"
.Sh DESCRIPTION
.Nm
is a virtual device corresponding to the pmax internal I/O space found
on DEC 2100, 3100, 5100 and 5000/200 systems.
.Pp
Internal I/O space spans the pmax physical address space, and is
mapped permanently in the kernel virtual space at the very early time
of the kernel startup procedure.
.Pp
.Nm
driver manages the internal I/O space of pmax.
.Bl -bullet -offset indent
.It
Address range management to avoid confliction of address space of
which devices probe by touching hardware port is difficult.
.It
Interrupt vector management.
.It
.Xr bus_space 9
and
.Xr bus_dma 9
implementation.
.It
Other utility functions.
.El
.Pp
.Nm
is always required to run the
.Nx
kernel.
.Sh SEE ALSO
.Xr pmax/intro 4 ,
.Xr bus_dma 9 ,
.Xr bus_space 9