+#define AO_FAT_EDIREOF 29
+
+/* ao_fat_setup return values */
+#define AO_FAT_FILESYSTEM_SUCCESS 0
+#define AO_FAT_FILESYSTEM_MBR_READ_FAILURE 1
+#define AO_FAT_FILESYSTEM_INVALID_MBR_SIGNATURE 2
+#define AO_FAT_FILESYSTEM_INVALID_PARTITION_TYPE 3
+#define AO_FAT_FILESYSTEM_ZERO_SIZED_PARTITION 4
+
+#define AO_FAT_FILESYSTEM_BOOT_READ_FAILURE 5
+#define AO_FAT_FILESYSTEM_INVALID_BOOT_SIGNATURE 6
+#define AO_FAT_FILESYSTEM_INVALID_SECTOR_SIZE 7
+
+void
+ao_fat_sync(void);
+
+void
+ao_fat_unmount(void);
+
+int8_t
+ao_fat_full(void);