I’ve received a Digi ConnectCore MP157 Development Kit. After some success in building a customized Yocto-Distro, i try to boot from SD-card.
I prepared a SD-card according to STM32 MPU wiki. But after setting boot switches to Off-On-On (S1 1…3) the SOM does not boot.
From what i have found in dev-kit schematics and device tree files the SD-card is connected to SDMMC2 on MPU (is this correct?). But MPU boots per default from SDMMC1 (if boot pins is b101).
So to be able to boot from SD-card on dev-kit one must set MPU OTP word 3 bits [4:3] to 2 ?
Are there more steps required to boot from SD-card?
Must OTP word 3 bits [2:1] also changed?
Must a special Boot/AFmux configuration in OTP words 5,6,7 set?
Must the device tree modified?
Digi you correctly create the SD card as “bootable”?
Can you reproduce the same with the latest Digi Embedded Yocto DEY-4.0-r3 images (not your custom build ones), from:
> I prepared a SD-card according to STM32 MPU wiki. But after setting boot switches to Off-On-On (S1 1…3) the SOM does not boot.
which Wiki are you referring to, please provide URL/link?
> From what i have found in dev-kit schematics and device tree files the SD-card is connected to SDMMC2 on MPU (is this correct?). But MPU boots per default from SDMMC1 (if boot pins is b101). > So to be able to boot from SD-card on dev-kit one must set MPU OTP word 3 bits [4:3] to 2 ?
Before you do so (can’t be undone) you might want to create a support case with Tech.Support@digi.com providing your dev-kit serial number or photo of it’s labels to get confirmed that there is no naming conflict between SDMMC1 and SDMMC2 in the documentation or the schematics.
To boot the Digi ConnectCore MP157 Development Kit from an SD card:
Set MPU OTP word 3 bits [4:3] to 2 to configure the MPU to boot from SDMMC2 instead of SDMMC1.
Modify the device tree to reflect the boot configuration changes.
Check Boot/AFmux configuration in OTP words 5, 6, and 7, if necessary.
Be cautious when modifying OTP memory as it permanently changes the MPU’s configuration.
For detailed instructions, consult Digi’s technical support or the official documentation and resources provided by STM32 MPU for the ConnectCore MP157 Development Kit.