sun3 port different then many others

Why is the sun3 port so different for so many of the other ports.

anything around bus, mmaping the bus, the structures, the abstraction
around it and all is there in many other ports (sun2, sparc, etc),
but not in the sun3 port.

It is just about getting impossible for me at my level of Unix kernel
experience to port the cgeight driver from the sparc port (where it
supports the P4 CG8) to the sun3 port.... the bus stuff just isn't there
(or I am completely able to find out it's equivalent).

At this point, SunOS 4.1.1_U1 with generic X11R6 is looking a whole lot
easier than NetBSD.

I really would love to use this framebuffer in NetBSD.  X11R6 is supposed
to have support for it... but without the cgeight driver in NetBSD I'm
not going to get very far.

I can't understand why things seem to be so different in the sun3 port.

I also find it interesting that there is a common sun68k directory, which
has many of the structures, etc that would make porting this easier, but
that is for Sun-2, not sun3 (sun3 only uses the sun3 and m68k dirs, where
I think the Sun-2 port uses sun2, m68k, and sun68k dirs).

Maybe someone can shed some light on this for me....

In particular, I'm stuck on:

1. No bus_space_tag_t type
2. No bus_space_mmap function
3. No bus_addr_t
4. No BUS_SPACE_MAP_LINEAR define

There may be more, but the compile stops at errors that lead to the
above.

Any clueful insights would be good.

Is this list active ?

-- Curt