Can we swap SDMMC pins in our design ?

[PS.2]

Does ST-Linux run for any configuration of eMMC pins, i.e. if it is connected to SDMMC1/SDMMC2/SDMMC3 . or do we need to fix as per reference design / Dev kits.

[PatrickF]

Hi @PS.2​ ,

either SDMMC1 or SDMMC2 with any of their available pins is possible for eMMC boot.

SDMMC3 is not available as boot source.

Nevertheless, outside default setting of pins needed to boot, you will need OTP customization (Word3 and Word5 to 7).

Default signals are SDMMC2_CLK (PE3), CMD (PG6) and D0 (PB14) for eMMC boot.

note that as only one data bit needed during BootROM boot, D1 to D7 are freely defined in device tree for TF-A/uBoot and Linux usage.

please have a look to :

• AN5031
• https://wiki.st.com/stm32mpu/wiki/STM32MP15_ROM_code_overview#Boot_from_e-E2-80-A2MMC-E2-84-A2

Regards