Secure boot for STM32H745

[ATank.1]

Hello Team,

We are developing a bootloader for STM32H745 MCU. Follwoing are requirements,

1. SDcard will contain the images for M7, M4 and External QSPI flash connected to H745 MCU

2. Planning to use Secure boot such as SBSFU. Please suggest if this is fine or any other option for secure boot considering available reference codes etc.

3. Bootloader will have touchGFX for displaying firmware upgrade progress

Please suggest reference codes available which can be refered for SBSFU

Thanks & Regards, 

 Anuj

[Jocelyn RICARD]

Hello @ATank.1 ,

there is no on the shelf SBSFU example for dual core.

You have some guide lines in the integration guide to achieve this.

You can use one master slot for M7 firmware, and another slot for the M4.

It is also possible to concatenate the 2 firmwares in one binary for update 

You will need to make many adaptations to SBSFU to support the access to the SDCard and the touchGFX interface.

Also, be aware that SBSFU is a secure boot, so is write protected. It is not supposed to be updatable.

Integrating graphical progress of update in a secure boot makes it more complex and subject to bugs.

One solution could be to implement 2 stage bootloader. First one very simple authenticating second stage that would include these fancy feature.

I guess it could be possible to implement this using the code provided in X-CUBE-SBSFU as base but I've never seen such implementation.

You also have other secure boot solutions such as the one provided by WoldSSL for instance.

Best regards

Jocelyn