Additional MicroSD using

Hello together,
i had installed my Board with eMMC and DEBIAN.
Now, I want to use the MicroSD as an additional space for this board.

BUT!
I don´t find the “device” - File for that. That anybody knows the device - Name for MicroSD?
thanks a lot and best regards

Matthias

Hi ZhexueM, the name is /dev/mmcblk0