I boot up my CM3L-Module in the IO Board over an image on USB.
After booting the uSDCard don't mount and I can't use as mass storage.
In the manual for CM3L there is a hint to this issue:
I don't know how to control the pin EMMC_EN_N_1V8. In another thread of this forum I read about the function raspi-gpio to control the gpio 47 (EMMC_EN_N_1V8). But this doesn't work.Note that once booted over USB, BCM2837 needs to re-enable the SD/eMMC device (by releasing
EMMC DISABLE N) to allow access to it as mass storage. It expects to be able to do this by driving
theEMMC EN N 1V8pinLOW,whichatbootisinitiallyaninputwithapullupto1V8. Ifanenduser
wishes to add the ability to access the SD/eMMC over USB in their product, similar circuitry to that
used on the Compute Module IO Board to enable/disable the USB boot and SD/eMMC must be used;
thatis,EMMC DISABLE NpulledlowviaMOSFET(s)andreleasedagainbyMOSFET,withthegate
controlled by EMMC EN N 1V8. Ensure you use MOSFETs suitable for switching at 1.8V (i.e. use a
device with gate threshold voltage, Vt, suitable for 1.8V switching).
How can I use the uSDCard if I boot my raspi from USB?
Thanks for your help.