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TZASC in imx6q SABRE Lite Board

Question asked by chirag Garg on Apr 17, 2015
Hi all,



I am working on the i.MX6 SABRE Lite board and trying to enable support for TrustZone features. I tried to enable TZASC1(TrustZone Address Space Controller) in i.MX6 board.


Following is the approach to enable TZASC :


1) Inside IOMUX set Genral purpose register #3 bits 11 and 12 to enable corresponding TZASC.
2) Inside IOMUX set Genral purpose register #9 bits 0 and 1 to configure corresponding TZASC for monitoring the transactions to DDR.
3) Implementation of tzasc driver. (According to ARM TZASC reference manual )


Firstly, Is it the right approach to enable TZASC for i.MX6 ?



I followed the above approach but TZASC is not working at all, even my kernel stopped when I am trying to modify the IOMUX GPR #9 bits.


On the other hand, As mention in Chapter 63 of i.MX6 reference manual the proper and preferred method of enabling the TZASCs, is by burning the TZASC_ENABLE fuse. I tried this approach, I fused the  TZASC_ENABLE bit and my tzasc driver got working. Even, I want to enable TZASC on other board without fusing the bit (through programming).

Thanks in advance.




Chirag Garg
IIT Madras , Rise Lab