.\"	$OpenBSD: wd.4,v 1.13 2007/05/31 19:19:53 jmc Exp $
.\"	$NetBSD: wd.4,v 1.4 1999/04/25 00:00:05 mjl Exp $
.\"
.\" Copyright (c) 1994 James A. Jegers
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. The name of the author may not be used to endorse or promote products
.\"    derived from this software without specific prior written permission
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
.\"
.Dd $Mdocdate: May 31 2007 $
.Dt WD 4
.Os
.Sh NAME
.Nm wd
.Nd WD100x compatible hard disk driver
.Sh SYNOPSIS
.Cd "wd* at wdc? flags 0x0000"
.Cd "wd* at pciide? flags 0x0000"
.Sh DESCRIPTION
The
.Nm
driver supports hard disks which emulate the Western Digital WD100x.
This includes standard MFM, RLL, ESDI, IDE, and EIDE drives, as well as
Serial ATA drives, and PCMCIA/CF storage media.
.Pp
The
.Cm flags
are used only with controllers that support DMA operations and
mode settings (like some
.Xr pciide 4
controllers).
The lowest order (rightmost) nibble of the
.Cm flags
define the PIO mode to use.
The next four bits indicate the DMA mode and the third nibble the UltraDMA
mode.
.Pp
For each set of four bits, the 3 lower bits define the mode to use
and the last bit must be set to 1 for this setting to be used.
For DMA and UltraDMA, 0xf (1111) means
.Dq disable .
For example, a
.Cm flags
value of 0x0fac (1111 1010 1100)
means
.Do
use PIO mode 4, DMA mode 2, disable UltraDMA
.Dc .
The special setting 0x0000 means
.Dq use whatever the drive claims to support .
.Sh SEE ALSO
.Xr intro 4 ,
.Xr pciide 4 ,
.Xr scsi 4 ,
.Xr wdc 4 ,
.Xr disklabel 5 ,
.Xr atactl 8 ,
.Xr disklabel 8 ,
.Xr fdisk 8