Hi,
Picked up an alpha version of this board and I’m really impressed with how the CM4 module works as an integrated solution. My issue is that I’d like to start saving data to the mass storage SD card slot, but it doesn’t appear to be working. I’ve tried various cards and formats, but none are showing up as a drive. Does it need enabling somewhere in the code, or might it be a hardware issue?
Kind Regards,
John.
From https://forums.raspberrypi.com/viewtopic.php?t=302634 I've added the following to /boot/config.txt
dtoverlay=sdhost,poll_once=off
Rebooted the CM4 and the second SD shows up!
Sorry for the delay and thanks for the follow-up message!
For others looking, on a non-Lite version of CM4 (so one that has eMMC storage), using dtoverlay=sdio instead of dtoverlay=sdhost worked for me. Additional info:
dtoverlay -h sdio
Name: sdio
Info: Selects the bcm2835-sdhost SD/MMC driver, optionally with overclock,
and enables SDIO via GPIOs 22-27. An example of use in 1-bit mode is
"dtoverlay=sdio,bus_width=1,gpios_22_25"dtoverlay -h sdhost
Name: sdhost
Info: Selects the bcm2835-sdhost SD/MMC driver, optionally with overclock.
N.B. This overlay is designed for situations where the mmc driver is
the default, so it disables the other (mmc) interface - this will kill
WLAN on a Pi3. If this isn't what you want, either use the sdtweak
overlay or the new sd_* dtparams of the base DTBs.