Value definition in FATFS

SDMMC\Driver\sdmmc.def 宣告了 SDMMC.DLL 公開的介面。
這幾個公開的介面，都實在 system.c 中。

結果：
決定 SDMMC card mount 行為的registry key:

HKEY_LOCAL_MACHINE\System\StorageManager\FATFS

中的

Flags

的各bit 定義在: COREOS\FSD\FATFS\fatfs.h。在MSDN 的FAT Filesystem registry Setting 這一篇也有說明：

FATFS_UPDATE_ACCESS         0x00000001  // update access times if set
FATFS_DISABLE_LOG           0x00000002  // disable event logging if set
FATFS_DISABLE_AUTOSCAN      0x00000004  // disable automatic ScanVolume()
FATFS_VERIFY_WRITES         0x00000008  // verify all writes (as opposed to a handful)
FATFS_ENABLE_BACKUP_FAT     0x00000010  // add a backup FAT to all formats
FATFS_FORCE_WRITETHROUGH    0x00000020  // Force fat to be always writethrough
FATFS_DISABLE_AUTOFORMAT    0x00000040  // disable automatic formatting of unformatted volumes

FATFS_WFWS_NOWRITETHRU      0x00010000  // disable writethrough on WriteFileWithSeek API, improve
                                       // memory-mapped file performance
FATFS_DISABLE_FORMAT        0x00020000  // disable format
FATFS_TRANS_DATA            0x00040000  // transact data on a write (i.e. clone cluster on every write)
FATFS_TFAT_NONATOMIC_SECTOR 0x00080000  // Use cluster 1 entry in FAT table for TFAT transaction,
                                       // since sector writes are non-atomic.
                                       // By default, TFAT uses the NOF field of the boot sector
FATFS_DISABLE_TFAT_REDIR    0x00100000  // Indicates to disable redirect the root directory to
                                       // another hidden director for FAT12 or 16, since root dir
                                       // isn't transacted in those cases
FATFS_TFAT_ALWAYS           0x00200000  // Always mark transaction status, even only one sector in
                                       // FAT is changed
FATFS_FORCE_TFAT            0x00400000  // Force TFAT transactioning even if volume isn't formatted
                                       // as TFAT
FATFS_LFN_EXTENDED          0x00800000  // Generate LFN entries for extended characters always
FATFS_TFAT_DISABLE_MOVEDIR  0x01000000  // Disable MoveFile on a directory for TFAT because it isn't
                                       // transaction-safe

所以要disable SD card 的 autoformat功能，就要設定 FATFS_DISABLE_AUTOFORMAT :
0x40

這個filesystem 好像會和nandflash 的filesystem 共用。所以大概會影響到nandflash filesystem..