On Thu, Jul 27, 2000 at 05:52:42PM -0700, Jun Sun wrote:
> Is there is easy way to turn off caching entirely? I understand I need
> to set k0 bits in config register. What about those C bits in TLB
> entries? My CPU only has primary cache.
The C bits are per page, the k0 bits are for KSEG0. If you want to
turn of caching, then you need to:
- change the k0 bits to uncached on startup, then flush the caches or a
writeback might corrupt your data.
- change the caching mode of the usermode pages by modifying the
definitions for PAGE_NONE etc. in pgtable.h.
- comment out the cache Create_Dirty_Exclusive instructions in r4xx0.c,
using them on uncached pages would corrupt data.
Which will make the kernel crawl awfully ...