WD1007-derived controllers. In this example, wdc0 is a WD1007-clone,
and wdc1 is a WD1003-clone. WD1007 controllers are generally ESDI
and IDE controllers.
wdc0 at 0x1f0-0x1f7 irq 14 on isa
wd0 at wdc0 targ 0: 322MB 1224 cyl, 15 head, 36 sec <disktype>
wdc1 at 0x170-0x17f irq 7 on isa
wd2 at wdc1 targ 0: (unknown size) <disktype>
devices hanging off controllers, any kind of controller.
A device on isa0 is called at probe(self), then attach(self)
A controller on isa0 is called at probe(self), then all it's children with
defined unit numbers are initialized by calling attach(subdev); next all
subdevices with unit ? are initialized by calling attach(sundev).
Almost all device entry points is now like the vax/sun model (intr being
the weird one)
controllers. New behaviour is that if the standard method fails, try
to recalibrate the drive. Success means the drive exists. patch by
hpeyerl@novatel.cuc.ab.ca (who owns several of these historical
artifacts)
