1) use interrupt vectors for specific zs chips rather than polling
all of them.
2) use softintr_schedule() and schedule it for a particular device
rather than poll all devices.
Unlike the other Sun machines, UltraSPARCs can have consoles run on different
chips than zs, so we need to support them. So, here we go:
Add a new PROM console driver with a major number and everything.
This is the default driver if nothing else attaches. It does not
use the keyboard driver since the PROM translates keystrokes itself.
(Unfortunately it also swallows L1-A).
Have the keyboard driver take over the console when it attaches on a
serial port. When a serial port detects a keyboard and attaches the
keyboard driver, it needs to provide a set of consdev vectors. They
keyboard driver will use those to send I/O to the keyboard and mouse.
Fix a bug causing interrmittent panics in interrupt dispatch.
Use interrupt vectors for softints.
Add a new send_softint interface.
Improved D$ flushing.
Improve traptrace and other debugging enhancements.
Make the initializer for BAUDLO depend on PCLK directly; it was incorrect on
some ports where PCLK is not 4.9152MHz.
XXX Is the default value actually used?