Minirouter SD slot not working


I’ve done a little self-help with the online info and Google but haven’t come up with the answer:

Should I expect the SD card slot to work on a minirouter with CM4 that has onboard eMMC?

I’ve got a couple of units and tried a couple of known good SD cards with the onboard reader and no luck with Raspbian or Ubuntu running. Using an external USB reader the cards work.

What I was trying to do: Boot up the device with the SD card to write an OS image to eMMC so I don’t have to open up the case every time I want to re-image. Is this a non-starter?


Hello, the application range of SD card has been marked in our commercial details. If the mini rounter with emmc is purchased, then the sd card is not able to install the system boot.