An Extensible Firmware Interface (EFI) system partition uses which filesystem type for compatibility?

The Extensible Firmware Interface (EFI) system partition utilizes the FAT filesystem, specifically the FAT32 variant, for compatibility reasons. This choice was made because the FAT filesystem is widely supported across different operating systems, ensuring that the EFI can function correctly regardless of the platform being used. The EFI firmware needs to be able to read and write files on the system partition without being hindered by proprietary or complex filesystem structures. FAT's simplicity and ubiquity make it an ideal choice for this purpose, as it allows for easy access to boot loaders and other necessary files during the system startup process.

The other filesystems mentioned, such as NTFS, ext4, and exFAT, do not provide the same level of compatibility across various firmware implementations, making them less suited for EFI system partitions. NTFS and ext4 are more complex and are typically associated with specific operating systems, while exFAT is geared towards flash drives and mobile devices rather than boot-related functions in a multi-OS environment.