STM32H745 sbsfu merge for cm4 and cm7?

[yolominwoo]

I'm successfully implemented IAP for stm32h745. so I wish upgrade to sbsfu.

Sbsfu has security firmware upgrade.

When i implement for IAP, Firmware file was merged cm4, cm7 binary file using Srecord.

If I merge files, won't the integrity of the firmware be lost?

[Jocelyn RICARD]

Hello @yolominwoo ,

if you merge the 2 binaries, it will be a new binary that you need to sign. It will be considered as one binary, and integrity and authenticity check will be done as if it was only one application.

Best regards

Jocelyn 

[yolominwoo]

Okay, I'm try it Thanks.

[yolominwoo]

Should the merging method be implemented in 1image sbsfu?

[Jocelyn RICARD]

Hello @yolominwoo,

The 1 image or 2 image in SBSFU stands for 1 or 2 slots.

In 1 image, you have 1 slot. This means that for updating your firmware you need a standalone loader that will first erase old firmware and write new one at same location (same slot)

In 2 images, you have 2 slots. 1 active and  1 for download. In that case, application firmware can be used to download the update firmware in the download slot. The SBSFU will then manage the update.

So, it depend on your product constraints.

Now, as you come from IAP, I would guess there was only 1 slot.

Best regards

Jocelyn