Ubuntu • Re: CM5 SD card not working on Ubuntu

I ran into the same issue. The root cause is that the MMC_SDHCI_OF_DWCMSHC driver is missing in the Ubuntu linux-raspi kernel configuration for this setup.

There are essentially two ways to solve this:

1. Rebuild the kernel with CONFIG_MMC_SDHCI_OF_DWCMSHC enabled (built-in or as a module), or
2. Build and install only the missing module against the running kernel and patch the system.

I have tested both approaches successfully, but rebuilding the entire kernel is unnecessarily heavy for most users. Building and installing only the missing module is much more practical.

Instructions

1. Install the kernel headers for the running `linux-raspi` kernel
2. Fetch the canonical Ubuntu `linux-raspi` source files for the `MMC_SDHCI_OF_DWCMSHC` driver
3. Create a minimal `Makefile` and compile the module against the running kernel
4. Install the module and load it
5. Finally, don't forget to enable the overlay `sdio-pi5`

Automated Solution

I consolidated all the commands I ran into a single Bash script.

The script is available at https://github.com/digiwest-lda/cm5-sdi ... ld-install. Run the script to build and install the `MMC_SDHCI_OF_DWCMSHC` for your kernel.

Statistics: Posted by jrosa — Mon Dec 15, 2025 12:47 pm

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