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In A7 platform with TZ extension , I know that there is a virtual MMU for non secure world, and I think it should be enabled after entering non secure world.
But the most confusing thing is that what has to be done with cache-----clean , invalidate or doing nothing?
Is there any special attention needed to make it work?
Nothing special - in general you can just run the same platform boot code that you would in a non-TrustZone system. The one main exception is that there are a few parts of CP15 which are secure modify only, so those settings have to be set up by the secure system before handing over control.
HTH, Pete
Thanks for your replying.
In my situation, the chip boots in secure world, and the cache and MMU are enabled.
I turn it to the non-secure world , enable the MMU and do nothing to cache,and then keep running. I'm wondering if there are some operations missing before or after this transition because my chip isn't working properly.