You haven't mentioned which board. If its Yosemite then you may have one of
the few not upgraded to 1.2 silicon. If so it won't work with the changes
committed by Ralf which requires the shared state for SMP boot. For further
discussion contact the email@example.com
[mailto:firstname.lastname@example.org]On Behalf Of Thomas Petazzoni
Sent: Monday, December 27, 2004 8:35 AM
Subject: Some cache questions
I'm using an RM9000 dual-core processor, buggy revisions (the one that
doesn't support the "Shared" cache state if I understood correctly).
When going through the CVS logs, I saw that Ralf quite recently changed
the cache mode from 4 to 5 in pgtable-bits.h. Is that change involved in
the use of the "Shared" cache state with newer RM9000 revisions that
don't have the bug ?
Currently, the KSEG0 cache coherency mode (2 lower bits of the CONFIG
register) is set to 3 during PMON (start.S file). When I write something
to the memory through KSEG0 with the first core, it doesn't appear to be
read by the second core. This indicates, in my opinion, that the cache
line of the first core hasn't been written to memory so that the second
core could use it. Am I right ?
If I want to correctly use both cores using KSEG0, should I set the mode
in the CONFIG register to 4 (so that I can work with buggy processors) ?
PETAZZONI Thomas - email@example.com
http://thomas.enix.org - Jabber: firstname.lastname@example.org
Fingerprint : 0BE1 4CF3 CEA4 AC9D CC6E 1624 F653 CB30 98D3 F7A7