On Wed, 7 Oct 2009, Mitch Bradley wrote:

Taking this one step further, I don't see any real good reason to continue 
supporting Sun4 going forward.  I got rid of my Sun4 systems long ago because 
it was just too hard to keep them working - after having used them long after 
most people had moved on.  Dropping Sun3 and Sun4 eliminates all vestiges of 
the sunmon interface and also allows dropping support for OBP version 1, 
which only shipped on SS1-class machines - the first machines in the Sun4c 
subclass.

Sun4c has also been broken for a long time and sun4d has never worked
properly. Is it time to also prune these ?.
That would leave only Sun4m in the 32bit kernel, which still works and
has plenty of ongoing user interest.