wd(HW)


wd -- EIDE disk and ATAPI host adapter driver

Description

wd is the driver for EIDE hard drives and ATAPI peripherals. It provides support for MP and MicroChannel systems, and for ATAPI CD-ROM and Seagate ATAPI TAPE devices.

To determine the support status of your host adapter, contact your system supplier or refer to the SCO Certified and Compatible Hardware web page.

Configuring the wd driver

You can configure the wd driver using entries in /etc/conf/cf.d/mdevice and /etc/conf/sdevice.d/wd. See mdevice(F) and sdevice(F). Changes to these files will only take effect if the kernel is relinked using link_unix(ADM) and the machine rebooted.

Configure wd driver-specific characteristics by editing the /etc/conf/pack.d/wd/space.c file.

Boot-time configuration of ATAPI and IDE peripherals

ATAPI peripherals are similar to SCSI devices. The system treats ATAPI peripherals as SCSI devices on a host adapter named ``wd''. Regular IDE hard disks are not ATAPI devices and are not treated as SCSI devices.

Typically the system automatically recognizes ATAPI peripherals. However, there may be times during initial system load when it might be helpful to use the Sdsk, Sflp, Srom, and Stp bootstring(HW) parameters to tell the kernel about the ATAPI devices on your system.

Specify the primary IDE controller as wd host adapter number ``0'' and the secondary controller (if present) as adapter ``1''. For example:

   Boot
   : defbootstr Stp=wd(1,0,0) Srom=wd(1,1,0)

This sequence of bootstrings specifies to use the default bootstring and indicates to the kernel that an ATAPI tape drive is on the secondary IDE controller in the master position and that an ATAPI CD-ROM drive is on the secondary IDE controller in the slave position.

The following list shows the types of devices that have been tested with the ATAPI interface.


Sdsk peripheral driver and:
Jaz drives

Sflp peripheral driver and:
LS120 and LS140 super floppy drives
Zip drives

Srom peripheral driver and:
CD-ROM drives
CD-ROM writers and rewriters (using Open Source cdrecord)
DVD-ROM drives
a variety of DVD-ROM writers (using commercial backup software)

Stp peripheral driver and:
Seagate Travan tape drives

The wd driver supports the wd.noscan bootstring(HW), which disables hardware checking by the driver. This prevents conflicts on systems that have both SCSI and ATAPI hardware enabled. This bootstring is only required during installation. Systems that include single types of mass storage devices (that is, EIDE/ATAPI or SCSI only) do not need this bootstring.

The wd.geom bootstring specifies the type of disk geometry to use:

physical example: 16 Hds 63 Sectors n Cyl
logical example: 255 Hds 63 Sectors n Cyl
translate use either (may be limited to 8 GB)

 physical    example: 16  Hds 63 Sectors n Cyl
 logical     example: 255 Hds 63 Sectors n Cyl
 translate   use either (may be limited to 8 GB)


NOTE: The wd.geom bootstring will not override disk parameters that have been written to the disk during a previous installation or the use of dparam(ADM). To forcefully remove disk parameters from a given drive, use this command:

dd if=/dev/zero of=/dev/rhddisknum bs=1 count=17 seek=376


Boot-time configuration of Ultra DMA (UDMA)

There are two bootstrings that can be used to change the default detection and setting of transfer modes for motherboards/controllers not recognized by the driver. The wd.udma bootstring has the following settings:

off disables UDMA (forces PIO mode)
auto if settings do not match motherboard, tries to sense and reprogram disk
0 or 16 udma 16 MB/sec
1 or 25 udma 25 MB/sec
2 or 33 udma 33 MB/sec
3 or 44 udma 44 MB/sec
4 or 66 udma 66 MB/sec
5 or 100 udma 100 MB/sec
6 or 133 udma 133 MB/sec

 off        disables UDMA (forces PIO mode)
 auto       if settings do not match
            motherboard, tries to sense and
            reprogram disk
 0 or 16    udma 16 MB/sec
 1 or 25    udma 25 MB/sec
 2 or 33    udma 33 MB/sec
 3 or 44    udma 44 MB/sec
 4 or 66    udma 66 MB/sec
 5 or 100   udma 100 MB/sec
 6 or 133   udma 133 MB/sec
The wd.debug=udma bootstring displays the current UDMA setting and values for motherboard and drives.

ioctl commands

The wd driver supports all standard SCSI ioctls that are defined in the <sys/scsicmd.h> header file and documented on the scsi(HW) manual page.

Diagnostics

See messages(M) for general information about kernel error messages, including a list of generic device driver errors.

Files


/usr/include/sys/scsicmd.h

SCSI interface header files

See also

boot(HW), link_unix(ADM), mdevice(F), mkdev(ADM), sconf(ADM), scsi(HW), sdevice(F)

``Adding SCSI host adapters and peripherals'' in the SCO OpenServer Handbook
SCO OpenServer System Administration Guide


© 2003 Caldera International, Inc. All rights reserved.
SCO OpenServer Release 5.0.7 -- 25 August 2003