Re: mtmsr...

On Wed, Sep 26, 2001 at 03:46:55PM -0700, Prasad, Siva wrote:

'PowerBoot' is the firmware I am using.

I preferred to use 2.2.14 because, it has PowerCore option, where I can use
750  with minimal changes.

I am not making any calls to firmware after that. This 'mtmsr' instruction
is third instruction and it hangs with out finishing. What might be the
problem that I have to fix to get this working.

Force's PowerBoot doesn't properly clean up caches before handing
control over to an external program.  You are probably having
cache problems that we have run into on some COTS Force boards.
I had to disable, flush, reenable L1 icache on the 680/G4, for
example.  linuxppc_2_4_devel's simple bootloader has a specific
CONFIG_PCORE option for this, in fact.

--
Matt Porter
MontaVista Software, Inc.
mporter@mvista.com

** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/

Matt Porter wrote:

Force's PowerBoot doesn't properly clean up caches before handing
control over to an external program.  You are probably having
cache problems that we have run into on some COTS Force boards.
I had to disable, flush, reenable L1 icache on the 680/G4, for
example.

So, you are really running on luck then.  When you disable the
cache, you are just fortunate that the necessary instructions
to do the remainder of the work just happen to be in main memory,
and that the cache was somehow implicitly invalidated so the ones
you need to get to this point aren't stale in the cache.  Are
you really sure the caches aren't cleaned up properly and this
sequence of operations isn't masking some other problem?


	-- Dan

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