[net.unix-wizards] uba_hd->lastiv

eric@aplvax.UUCP (10/19/83)

	I have seen a couple of uba device drivers which reference
uba_hd->lastiv. Now, we are currently running an early distribution
of 4.1, and our definition of uba_hd does not have a lastiv field.
Can someone tell me what I need to do to add it, so that I can use
these new drivers (such as for the dmf32)? I would appreciate any
pointers that you can give me.

-- 
					eric
					...!seismo!umcp-cs!aplvax!eric

aps@decvax.UUCP (Armando P. Stettner) (10/22/83)

The object uba_hd->lastiv was added to late 4.1 systems to support
those UNIBUS devices that did not have hardwired interrupt vectors.
During autoconfig, this value is decremented and the value used
as an interrupt vector to be loaded into a device (currently
used by the DMF and UDA drivers).  Lastiv is last interrupt
vector.
	aps.

ron%brl-vgr@sri-unix.UUCP (11/01/83)

From:      Ron Natalie <ron@brl-vgr>

uba_hd->lastiv is the last allocated unibus interrupt vector.
It is used for "smart" peripherals that you tell them where to
interrupt to under program control.  The way to use it is to
decrement it by 4 (2 bytes for the PC, 2 bytes for the PS) and
use the resulting number as the vector for that peripheral.

It is just set in autoconf right before the ubaaccess call to
some reasonable number (0x200 by default).

-Ron