SDMMC1, SDMMC2 : Only one Memory Boot Device can be assigned to TF-A simultaneously.

[SullyNiu]

I’m working on a custom STM32MP257DAK3 board.
In STM32CubeMX, I need both SDMMC1 (SD card) and SDMMC2 (eMMC) to be supported as possible boot devices.

When I check both:

SDMMC1 → Memory Boot Device

SDMMC2 → Memory Boot Device

The following error appears in IPs assignment rules:

Faulty state detected for SDMMC1, SDMMC2 : Only one Memory Boot Device can be assigned to TF-A simultaneously.

I understand that TF-A allows only one memory boot device at a time.
However, our hardware design supports dual boot options (either from eMMC or SD card). How can I fix this error?

[Ghofrane GSOURI · Accepted solution]

Hello @SullyNiu 

"Faulty state detected for SDMMC1, SDMMC2: Only one Memory Boot Device can be assigned to TF-A simultaneously." is  a non-blocking warning so you can still generate code and proceed.

THX

Ghofrane