Inst TLB miss.

Nick Thomas nick.thomas at
Fri May 21 18:04:50 UTC 2010


My colleague and I are trying to upgrade our RTEMS OS from 4.7.1 to 4.7.3 to
see if that fixes our problems which have been detailed here recently.

At the same time we have added the -fno-strict-aliasing to the compiler
command line - as suggested by Thomas Doerfler. Also adding this to all of
the other project modules.

It has compiled OK, but now we see a (inst TLB miss) exception very soon
after power up!
Never seen this before, but I can't believe it is due to the
-fno-strict-aliasing addition.

It must be due to something else we missed.

This is running on a PowerPC 405 based CPU.

I thought the PowerPC 405 had hardware cache for this sort of thing. Indeed
the 0x1200 exception vector for TLB miss doesn't have any code, so I think
we are expecting the hardware to take care of this.

What could we have missed to start getting this new problem?



Nick Thomas
Email: nick.thomas at 

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