Secure and Non secure folders

[Keerthi]

Hi,

I would like to know where to write the code either in secure or non-secure folder. What is the exact purpose of this folders. I want to encrypt a CAN message and send it. I have done without enabling trust zones previously. But now I enabled the trust zone and would like to write CAN drivers, encryption key change etc. I am using NUCLEO-H533RE boards for development. Please let me know. There are examples problems but did not actually had these two folders. Thanks in advance.

[Pavel A.]

>  I want to encrypt a CAN message and send it

This is not related to "secure" vs "non-secure" separation or TrustZone. Please see the documentation on the H533RE. 

[Keerthi]

Hi,

Thanks for the reply. When enabling the FDCAN, it has two options where to enable either in the secure or non-secure zone as shown in the below image. But I am not sure what exactly the purpose of this folders. 

[Pavel A.]

If so, then you probably do not need to enable the Trustzone at this time at all? Just revert to previous state and enjoy simplicity. Do you need help with encryption of the data sent over CAN?

[Keerthi]

Hi,

I really would like to work with trust zone enable and learn about it. If you have any idea please let me know. 

Do you need help with encryption of the data sent over CAN?

--I already had experience with cryptography with other company microcontroller. I would like to know in STM. Yes

Thanks in advance.

[Pavel A.]

> I really would like to work with trust zone enable and learn about it. If you have any idea please let me know. 

Spending some time reading on Cortex-M33 and separation of secure/nonsecure zones may be a good idea. If you don't have time, this is perfectly OK. Then find a consultant.

[Keerthi]

Thank you