> I never understood why cache flush is needed at all.  Any secondary
> cache for 030 works with the physical address which makes (at least
> seems to me) it unnecessary to flush it when kernel switches context.

Think on it a bit longer.  Consider the following scenario:
	Process A stores something in the page at virtual address 0 at
		physical address 0x00040000
	Process B is switched in and pages in virtual address 0x10000 at
		physical address 0x00040000
If the caches aren't flushed, process B could see the cached contents
from process A's virtual address 0.

-allen

-- 
  Allen Briggs - end killing - briggs@bev.net ** MacBSD == NetBSD/mac68k **
   Where does all my time go?  <a href="http://www.netbsd.org/">Guess.</a>