The option "Detect FAT boot sector" (CYGSEM_IO_DISK_DETECT_FAT_BOOT) can be used with certain types of removable media which are treated undeterministically by Windows PCs, such as USB keys. These usually contain a partition table, but if completely wiped, Windows will not recreate the partition table, and instead place a FAT filesystem directly on the device with no partition table. Enabling this option detects this and fabricates a partition table in memory instead. This option is usually only needed on systems which use removable media likely to be shared with Windows PCs, as indicated from low level drivers with the CYGINT_IO_DISK_DETECT_FAT_BOOT_DEFAULT CDL interface.
The CDL interface CYGINT_IO_DISK_ALIGN_BUFS_TO_CACHELINE indicates to the disk I/O package, and to its users, that data transfer buffers need to be aligned to data cache line boundaries.
The CDL interface CYGINT_IO_DISK_REMOVABLE_MEDIA_SUPPORT indicates that the hardware disk driver implements removable media support. This will cause the disk I/O package to implement the CYG_IO_SET_CONFIG_DISK_EVENT and CYG_IO_GET_CONFIG_DISK_EVENT configuration option keys.