STM32N6 - How to disable the Trust Zone and safety related mechanisms

[Laney]

Hello! 

I have STM32N6570-DK and i would like to disable or make Trust Zone transparent to me and develop the project without safety like your products with cortex M3,M4 and M7 cores with all resources available. 

I can find some video content on disabling Trust Zone on STM32L5 and STM32U5 but not for STM32N6. 

STM32CubeIDE offers me a Secure or Secure-Non Secure project generation. Any tips ? 

Thank you 

[STackPointer64]

Hello @Laney, and welcome to ST community!

In the Project Manager, you can select AppNS to generate only the non-secure version of the project, which is most likely what you are looking for.

Best regards,

[Laney]

Hello @STackPointer64 ! Thank you for reaching out, and happy new year to all. 

I've tried suggested. To generate only non-secure project. CubeMX prompted the warning, and after the generation the code does not build.  

 Also, in the CubeMX new project wizard, there is no option to generate only non-secure or trust zone disabled project. Is this currently not supported or ? 

Next, i shifted towards templates located in STM32Cube_FW_N6_V1.3.0 as instructed by user manual  - UM3249 Getting started with STM32CubeN6 for STM32N6 series.

For template STM32Cube_FW_N6_V1.3.0/Projects/STM32N6570-DK/Templates/Template_FSBL_LRUN i don't find any commentary that this project has security disabled. This one was my best bet to might be the right one... 
 
Does ST provide any training how to work with the TrustZone and security on STM32N6 devices ? 
Is disabling TrustZone and using MCU more traditionally like Cortex M3-M7 even feasible with this device ?

Thank you 

[STackPointer64]

Hello @Laney ,

I stand corrected; please excuse the misinformation in my previous message. Due to the architecture of N6, both secure and non-secure projects need to be generated for successful compilation. Regarding using the MCU more traditionally like Cortex-M3 to M7 (except M33, M35P, and M55), the only way is to enable and configure peripherals in the Non-Secure domain (AppNS). After generating the project, you should edit only the non-secure project. That’s all.

Regarding your question about training material, I suggest you check our knowledge base articles and wiki for N6 guides:

• Knowledge Base Articles
• STM32N6 Wiki

Best regards,

[RomainR.]

Hi @Laney 

Due to its architecture, it's not possible to disable TrustZone on STM32N6.
After reset, the device always starts the BootROM execution in secure mode, then jump in a FSBL application which is still in secure mode.
From CubeMX you have the possibility to generate projects as below:
- FSBL + Application Secure
- FSBL +  Application Secure + Application Non Secure (integrate firmware isolation)

If you do not need this security model, you should use other STM32 device without TrustZone feature.

Best regards,

Romain,