On Thu, 11 Jul 2002, Ralf Baechle wrote:
> The R3000 cache manipulation mechanism is implemented by giving magic
> meaning to store instruction while the isolate cache and swap cache bits
> are in use. By their very implementation they're both incompatible with
> normal operation of caches and therefore can only be used from uncached
> space.
Well, docs state only the cache that acts as the D-cache gets isolated
and the one that acts as the I-cache always functions normally (and the
real D-cache has all the logic needed to pretend it's an I-cache
successfully). Thus running from an uncached space is not needed. I
haven't checked it explicitly, but the flushing functions would fail
(hang) quite soon otherwise and they don't.
--
+ Maciej W. Rozycki, Technical University of Gdansk, Poland +
+--------------------------------------------------------------+
+ e-mail: macro@ds2.pg.gda.pl, PGP key available +
|