U-boot cannot read SD card - is this expected to work?

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Hi, I’m the Toradex AI Assistant. The Toradex Support team will follow up with you shortly!

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Yes, U-Boot should be able to read an SD card on the Verdin iMX8M Plus. Based on the U-Boot output you provided, it seems that U-Boot is not detecting the SD card as MMC Device 0. Here are a few steps you can take to troubleshoot this issue:

  1. Check Device Tree Configuration: Ensure that the device tree configuration for the SD card interface is correct. The SD card interface should be properly defined in the device tree source (DTS) files. Verify that the relevant nodes are enabled and correctly configured.

  2. Check U-Boot Configuration: Make sure that U-Boot is configured to support the SD card interface. This includes enabling the appropriate drivers and ensuring that the SD card interface is not disabled in the U-Boot configuration.

  3. Check Hardware Connections: Since you mentioned that the SD card works in Linux and Tezi, it is less likely to be a hardware issue. However, double-check the hardware connections and ensure that the SD card interface has the correct pull-up resistors and other necessary components.

  4. Use mmc rescan Command: You mentioned that you tried the mmc rescan command, but it did not help. Ensure that you are using the correct device number for the SD card. For example, if the SD card is on FSL_SDHC: 1, you should use:

    mmc dev 1
mmc rescan
mmc info

  5. Check U-Boot Logs: Look for any error messages or warnings in the U-Boot logs that might indicate why the SD card is not being detected. This can provide clues about what might be going wrong.

  6. Update U-Boot: Ensure that you are using the latest version of U-Boot provided by Toradex. There might be bug fixes or improvements in newer versions that could resolve the issue.

If you have verified all the above steps and the issue persists, it might be helpful to reach out to Toradex support with detailed information about your custom carrier board design and the steps you have taken so far. They might be able to provide more specific guidance based on your hardware and configuration.

Please, also check if these links can help you solve your problem:

External storage 32GB on a carrier board with Colibri iMX7, iMX8.