STM32U575 TrustZone access non secure area from secure mode

[fed]

Flash Memory is divided in different zones Secure (also protected by watermark), NCS and NS. All of such zone are defined in the the partition_stm32U575xx.h and SAU is enabled.

MCU is in secure mode and want to write in the non secure area.

Erasing return without errors, writing return without errors, but reading back what have been wrote doesn't match with the original data.

We had similar issue on the L5 and in that case we had to promote the flash to secure using HAL_FLASHEx_GetConfigBBAttributes, perform all write operations then demote all blocks to non secure. 

Unfortunately the same trick here doesn't work.

Any suggestion or minimal example?

Thanks in advance

 

[Roger SHIVELY]

Hello @fed,

 

This post has been escalated to the ST Online Support Team for additional assistance. 

We'll contact you directly.

 

Regards,

Roger

[fed]

Dear Roger,

           I have been contacted, but the problem is still open. At the moment I provided all information that has been requested but no answer since the last week.

 

Have a nice day

FDA