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Trust Zone on Raspberry Pi unexpected behaviour?

Vamsi Krishna Atluri

I am working on the trust zone extension on raspberry pi B+ which has the ARM1176JZF-S processor. According to given documentation on arm11, there will be 3 exception vector tables each for Secure world, Non-secure(NS) world and monitor mode resp. And c12 register will hold the base address of both secure and NS world exception vector table base addresses.

I added both these addresses to the c12 register in their corresponding worlds(Secure / NS). I tried SWI (svc) in both worlds. I found that it is working fine in secure world but in the NS world the control goes to the NS reset handler for a SWI instead of SWI handler. I used the following commands :

For secure world : 
     LDR r0, =_start //_start - base address of secure vector table 
     MCR p15, 0, r0, c12, c0, 0 
For Non-secure World : 
     LDR r0, =_ns_start //ns_start - base address of non-secure vector table      
     MCR p15, 0, r0, c12, c0, 0

Here is my code: arm_bare_metal/trustzone-smc at master · avk7vk/arm_bare_metal · GitHub

Please let me know the issue here .

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