I-Cache incoherence

Marc Lörner marc.loerner at hob.de
Tue May 27 15:19:06 UTC 2008


Hi,
when testing snapshot 7.0-Stable from 05/2008 and
8.0-Current installation discs, it seems that the image
gets loaded from disc into data cache.

When we now try to access this just loaded data as instructions
=> I-Cache is not coherent and HW just hangs
(after output: "Trying to mount root from /dev/md0"
and before choosing the terminal-emulation)

I tried to verify this assumption with inserting a"ptc.l"-instruction
before every itc.i in Instruction_TLB, so we force the HW to ensure
coherency.
=>It now runs further to sysinstall.

Maybe the before mentioned "ptc.l" can be exchanged with fc.i or some
other mechanism to ensure coherency.

Unfortunately I still get a panic on probing devices in sysinstall.

Hope this helps to get a solution for the I-Cache coherence problems,
Marc Loerner


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