Edge
This special mode can be used to restore the device in cases such as: boot sector corruption, or flash of another OS than Unipi. This mode allows direct access to the eMMC storage via the USB-C INIT connector. On Edge variants without USB A ports, it can used to flash/backup the OS image.
To access the internal eMMC storage, you will need to install a utility called rpiboot.
rpiboot -d /usr/share/rpiboot/mass-storage-gadget64