Minimal demo of STM32H753 Secure Access mode

[Pavel A.]

Dear experts,

I'd like to try the Secure Access mode of H753, but overwhelmed by the SBSFU and SFI documentation.

I'm thinking about a minimal test for the "secure user memory" - without SFI, Secure Package Creator etc., or as little as possible:

• Burn a small "blinky"-like test at the start of flash, 0x08000000, in normal unprotected mode, and another small test at the next flash page.
• Then set the option bytes so that my code at 0x08000000 becomes the secure area, and activate secure mode.
• After reset, the MCU jumps to my test, in secure mode.
• My test then jumps to the code in another flash page, exiting the secure mode.
• All this without any other ST functionality in the system bootloader, and no any crypto stuff yet.

The question: can this be done without fiddling with the "Root secure services"?

 is such a demo available? 

Thanks in advance,

-- pa

[Pavel A.]

RM0433 pg. 238 says that the "Secure area setting service" can be called only once, and the related option bytes can be only set thru this service.

The RM doesn't disclose how to call this service. Is this some absolute address in the "system ROM"? should it be called from temporary code running in the RAM?

I have only one eval. boards and am afraid to do something irreversible.

Won't this stuff revert to the "virgin" state after mass erase and deleting the protected areas?

-- pa

[Pavel A.]

Up