second argument. The NuBus autoconfig code had to be reorganized as a
result of this, and looks much more like a directly-attached bus now.
These changes eliminate __BROKEN_INDIRECT_CONFIG.
occupy a slot. This is necessary so that GRFIOCMAP can find the correct
physical address of the framebuffer. Fixes P550, some LC models, and
perhaps the PB520.
Also change the device probing scheme to use something a bit more rational.
A current side-effect is that nubus cards are double-mapped. I expect
to fix that shortly.
Also change splclock() to block everything but serial hardware interrupts.