This document describes the FAT filesystem provided in eCos. This is implemented by the FATFS package which uses the facilities of the FILEIO package to present its functionality to the user.

The FAT filesystem supports FAT12, FAT16 and FAT32 disk formats.

The FAT filesystem includes optional support for long file names. This functionality is covered by patents belonging to Microsoft in several territories, including Europe and the the USA. By default the long file name support in eCos (CYGCFG_FS_FAT_LONG_FILE_NAMES) is disabled. If you wish to enable this feature on products that are distributed within these territories then you may need to aquire a license from Microsoft.