NAME    [Toc]    [Back]

     wd - WD100x compatible hard disk driver

SYNOPSIS    [Toc]    [Back]

     wd* at wdc? channel ? drive ? flags 0x0000
     wd* at pciide? channel ? drive ? flags 0x0000

DESCRIPTION    [Toc]    [Back]

     The wd 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.

     The flags are used only with controllers  that  support  DMA
operations and
     mode settings (like some pciide(4) controllers).  The lowest
order
     (rightmost) nibble of the flags define the PIO mode to  use.
The next
     four bits indicate the DMA mode and the third nibble the UltraDMA mode.

     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  ``disable''.   For  example,  a
flags value of
     0x0fac  (1111 1010 1100) means ``use PIO mode 4, DMA mode 2,
disable
     UltraDMA''.  The special setting 0x0000 means ``use whatever
the drive
     claims to support''.

SEE ALSO    [Toc]    [Back]

     intro(4),  pciide(4),  scsi(4),  wdc(4),  disklabel(5),  atactl(8),
     disklabel(8), fdisk(8)

OpenBSD     3.6                        October      15,      1998