SBSFU_Boot on STM32U5A9

[Mourice]

Hi, 

I am working with the SBSFU_Boot on the STM32U5A9 chip. After the SBSFU_Loader has written the update image into internal memory, a reset happens in order for the SBSFU_Boot to write the image to be booted. When performing the update, it ends up in a process where it has to do some encryption. The SAES engine is initialized successfully, and then AES_Encrypt is called. This keeps on failing because a read error is reported in the SAES->SR reports a read error upon enabling the SAES peripheral. 

It should be noted that the initialization and encryption sequence is strictly followed per instructions in RM0456 Rev 6 sections 50.4.4 (Initialization of SAES) and 50.4.8 (ECB/CBC encryption sequence) respectively. 

What am I missing?

[Jocelyn RICARD]

Hello @Mourice ,

From your description it is not clear if you have made adaptations or not.

Could you please provide more details?

Best regards

Jocelyn

[Mourice]

Hi Jocelyn, 

I have not made any adaptations. 

Best regards,

Mourice. 

[Jocelyn RICARD]

Hello @Mourice ,

OK thank you. I will try to reproduce the issue.

Best regards

Jocelyn

[Mourice]

Hi @Jocelyn RICARD ,

I am looking forward to your findings. 

Best regards,

Mourice. 

[Jocelyn RICARD]

Hello @Mourice,

I couldn't reproduce your issue.

I used latest STM32Cube_FW_U5_V1.8.0 as base and followed readme to adapt B-U585I-IOT02A to STM32U5A9J-DK.

It is booting properly and update is working as expected.

I join the adaptation I made so that you can check on your side.

Best regards

Jocelyn

[Mourice]

Hi Jocelyn,
I will try out your adaptation and give you feedback. 

Best regards,

Mourice. 

[Mourice · Accepted solution]

Hi Jocelyn, 

It turns out that the SAES wasn't configured correctly. After this was sorted out, it worked. 

Best regards,

Mourice.