标签：固定 好的 sed str initial tor serial order span
disk_status用来查询当前存储设备的状态
DSTATUS disk_status (BYTE pdrv /* [IN] Physical drive number */);
返回当前设备状态值,具体指在下面描述. FatFs 只使用STA_NOINIT和STA_PROTECT.
该函数调用存储设备初始化方法.
DSTATUS disk_initialize (BYTE pdrv /* [IN] Physical drive number */);
该方法返回初始化设备状态标志, 返回值与disk_status函数的返回值一致.
该函数初始化存储设备使之可以支持一般的读写方法. 当该函数调用成功,STA_NOINIT标志将会清除.
Remarks: 该函数必须在Fatfs模块的控制下,应用程序不能调用该函数, 当需要重新初始化文件系统的时候,调用 f_mount即可.
该方法在读写存储设备扇区的时候被调用.
DRESULT disk_read (BYTE pdrv, /* [IN] Physical drive number */BYTE* buff, /* [OUT] Pointer to the read data buffer */DWORD sector, /* [IN] Start sector number */UINT count /* [IN] Number of sectros to read */);
该函数将会写入一个或者多个扇区数据到设备中.
DRESULT disk_write (BYTE drv, /* [IN] Physical drive number */const BYTE* buff, /* [IN] Pointer to the data to be written */DWORD sector, /* [IN] Sector number to write from */UINT count /* [IN] Number of sectors to write */);
写入地址并非一直都是字对齐的,处理方法和read一样.
为了好的文件系统吞吐量,多扇区写入不要切换成单扇区写入.
Fatfs支持硬件层的延迟写入. 当写入数据存放在写入缓存中或者写入操作正在执行,写入过程不会立即执行.disk_ioctl CTRL_SYNC 发出时,写入操作完整写入,因此,如果延迟写入被实现,硬盘的写入性能将会被优化..
应用不能直接调用该函数,否则,文件系统会崩溃.
当 _FS_READONLY == 1 时,该函数不需要实现.
该函数操作一些特定的设备属性和一些除了读写之外的属性.
DRESULT disk_ioctl (BYTE pdrv, /* [IN] Drive number */BYTE cmd, /* [IN] Control command code */void* buff /* [I/O] Parameter and data buffer */);
Fatfs只支持以下五个独立属性.
| Command | Description |
|---|---|
| CTRL_SYNC | 保证文件系统已经结束挂起写入处理. 如果IO模块有写入缓存, 此时写入缓存必须立即写入.如果在disk_write写入操作中直接写入了,就不需要关注该指令. |
| GET_SECTOR_COUNT | 将指定驱动器号的设备的扇区总数返回,返回缓冲区是DWORD类型. 该指令只会被 f_mkfs 和 f_fdisk 方法调用,去创建新的分区. 前提是 _USE_MKFS == 1 或者 _MULTI_PARTITION == 1. |
| GET_SECTOR_SIZE | 返回word类型的扇区字节数量. 支持的返回值是512, 1024, 2048 和4096. 该指令只有在打开了可变扇区配置的时候才会被调用, _MAX_SS > _MIN_SS. 如果使用以下配置, _MAX_SS == _MIN_SS, 该指令不会被调用且只能在指定的扇区大小下工作. |
| GET_BLOCK_SIZE | 返回flash类型的存储器中一个block中包含的扇区数量. 可选返回值1 到32768 . 当使用norflash或者位置block大小的时候,返回值为. ,该指令只有在 f_mkfs 被调用,或者系统尝试将数据区和擦除块对其的时候调用.需要_USE_MKFS == 1. |
| CTRL_TRIM | 通知设备某个block的数据不在需要可以被删除调了. 扇区号码存储在 DWORD array {<start sector>, <end sector>} pointed by buff. 这是一个ATA设备支持的特定指令. 如果设备不是flash或者不支持该接口,该指令什么也不用做. Fatfa不会检查该指令的返回值,即使擦除失败. 该函数在f_mkfs方法中移除文件簇链的时候被调用,调用前提 _USE_TRIM == 1. |
Fatfs不再使用其他扩展指令或者其他用户定义指令. 以下表格显示了一些非标准用户指令.
| Command | Description |
|---|---|
| CTRL_FORMAT | Create a physical format on the media. If buff is not null, it is pointer to the call-back function for progress notification. |
| CTRL_POWER_IDLE | Put the device idle state. STA_NOINIT in the current status flags may not be set if the device goes active state by generic read/write function. |
| CTRL_POWER_OFF | Put the device off state. Shut-down the power to the device and deinitialize the device interface if needed. STA_NOINIT in the current status flags must be set. The device goes active state bydisk_initialize function. |
| CTRL_LOCK | Lock media eject mechanism. |
| CTRL_UNLOCK | Unlock media eject mechanism. |
| CTRL_EJECT | Eject media cartridge. STA_NOINIT and STA_NODISK in status flag are set after the function succeeded. |
| MMC_GET_TYPE | Get card type. The type flags, bit0:MMCv3, bit1:SDv1, bit2:SDv2+ and bit3:LBA, is stored to a BYTE variable pointed by buff. (MMC/SDC specific command) |
| MMC_GET_CSD | Get CSD register into a 16-byte buffer pointed by buff. (MMC/SDC specific command) |
| MMC_GET_CID | Get CID register into a 16-byte buffer pointed by buff. (MMC/SDC specific command) |
| MMC_GET_OCR | Get OCR register into a 4-byte buffer pointed by buff. (MMC/SDC specific command) |
| MMC_GET_SDSTAT | Get SDSTATUS register into a 64-byte buffer pointed by buff. (SDC specific command) |
| ATA_GET_REV | Get the revision string into a 16-byte buffer pointed by buff. (ATA/CFC specific command) |
| ATA_GET_MODEL | Get the model string into a 40-byte buffer pointed by buff. (ATA/CFC specific command) |
| ATA_GET_SN | Get the serial number string into a 20-byte buffer pointed by buff. (ATA/CFC specific command) |
| ISDIO_READ | Read a block of iSDIO registers specified by command structure pointed by buff. (FlashAir specific command) |
| ISDIO_WRITE | Write a block of data to iSDIO registers specified by command structure pointed by buff. (FlashAir specific command) |
| ISDIO_MRITE | Change bits in an iSDIO register specified by command structure pointed by buff. (FlashAir specific command) |
当 _FS_READONLY == 1或者_MAX_SS == _MIN_SS的时候,该函数不被调用.
该函数获取当前时间.
DWORD get_fattime (void);
在一个DWORD类型中返回当前时间. 位区间定义如下:
即使系统没有实时时钟,该函数也应该返回一个固定的时间配置. 如果返回零,系统文件将没有时间戳.
当 _FS_READONLY == 1 或者 _FS_NORTC == 1的时候,不需要该函数.
标签：固定 好的 sed str initial tor serial order span
原文地址：http://www.cnblogs.com/dengxiaojun/p/306145dad2a55b31ab2954d34d21d37c.html
