How do I know which world the system is in? Secure or Non-Secure for i.MX6Solo?

[ruitan]

Hi there,

I am currently using the i.MX6Solo (Cortex-A9).

1. Could you please tell me how can I know which world the system is in? secure or normal world?

2. How to disable the Trustzone, is this possible?

Thank you!

Rui

[igorpadykov]

Hi Rui

one can do it reading read SCR register, as in examples on

http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.faqs/ka15417.html

Trustzone is security architecture extension and one may use or not use it, seems

it is not possible to disable it

http://infocenter.arm.com/help/topic/com.arm.doc.prd29-genc-009492c/PRD29-GENC-009492C_trustzone_sec...

Best regards

igor

-----------------------------------------------------------------------------------------------------------------------

Note: If this post answers your question, please click the Correct Answer button. Thank you!

-----------------------------------------------------------------------------------------------------------------------

[ruitan]

Hi Igor,

Thank you for your help!

Yesterday I tried to read out the value of SCR register in CP15 C1, and the value was 0x00000000. The NS bit (0th bit, non-secure bit) was 0, so that the system was in the secure world. But I still got two questions.

[1] I checked the description from "Cortex-A9 Technical Reference Manual" Revision: r4p1, in page 4-6 (pdf page 55), the SCR register has two superscript notes, one says, "No access in Non-secure state.", another says "SCR[6] is not implemented, RAZ/WI.".

So Is there a SCR register in Cortex-A9's CP15 C1?

[2] How can I switch from the secure world to the normal world? What is the default world after startup?

Thank you again Igor!

Best Regards,

Rui