Recent ESP32-S2 release can mount SD card,
after setting pinout and SPI, this works
storage.mount(vfs, "/sd")
os.listdir("/sd") lists files stored on the SD card.
['KERNEL.SYS', 'COMMAND.COM', 'INVADERS.COM', etc..

Now I want to copy a file from PC to the mounted SD card
but linux PC usb-storage interface doesn't "see" mounted
"/sd" directory

cp README.md /media/guest/CIRCUITPY/sd/
cp: cannot create regular file '/media/guest/CIRCUITPY/sd/': Not a directory