NAME
wd —
WD100x compatible hard disk
driver
SYNOPSIS
wd* at wdc? flags 0x0000
wd* at pciide? flags 0x0000
DESCRIPTION
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, and PCMCIA/CF storage
media.
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
intro(4), pciide(4), scsi(4), wdc(4), disklabel(5), atactl(8), disklabel(8), fdisk(8)