The spec says that it supports microSD cards “up to 2TB”.
In the schematics, it lists the TE Connectivity 2290741-1 card slot and the Microchip USB2642 card controller, that supports Secure Digital (SD, FAT16 up to 2GB), SD High Capacity (SDHC, FAT32, 4-32 GB), and SD Extended Capacity (SDXC, exFAT, 64GB - 2TB) cards.