sfatfs.html
1 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd"> 2 <html lang="en"> 3 <head> 4 <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> 5 <meta http-equiv="Content-Style-Type" content="text/css"> 6 <link rel="up" title="FatFs" href="../00index_e.html"> 7 <link rel="alternate" hreflang="ja" title="Japanese" href="../ja/sfatfs.html"> 8 <link rel="stylesheet" href="../css_e.css" type="text/css" media="screen" title="ELM Default"> 9 <title>FatFs - FATFS</title> 10 </head> 11 12 <body> 13 14 <div class="para"> 15 <h2>FATFS</h2> 16 <p>The <tt>FATFS</tt> structure (filesystem object) holds dynamic work area of individual logical drives. It is given by application program and registerd/unregisterd to the FatFs module with <tt>f_mount</tt> function. Initialization of the structure is done by volume mount process whenever necessary. Application program <em>must not</em> modify any member in this structure, or the FAT volume will be collapsed.</p> 17 <pre> 18 <span class="k">typedef</span> <span class="k">struct</span> { 19 BYTE fs_type; <span class="c">/* FAT type (0, FS_FAT12, FS_FAT16, FS_FAT32 or FS_EXFAT) */</span> 20 BYTE pdrv; <span class="c">/* Hosting physical drive of this volume */</span> 21 BYTE n_fats; <span class="c">/* Number of FAT copies (1,2) */</span> 22 BYTE wflag; <span class="c">/* win[] flag (b0:win[] is dirty) */</span> 23 BYTE fsi_flag; <span class="c">/* FSINFO flags (b7:Disabled, b0:Dirty) */</span> 24 WORD id; <span class="c">/* Volume mount ID */</span> 25 WORD n_rootdir; <span class="c">/* Number of root directory entries (FAT12/16) */</span> 26 WORD csize; <span class="c">/* Sectors per cluster */</span> 27 <span class="k">#if</span> FF_MAX_SS != FF_MIN_SS 28 WORD ssize; <span class="c">/* Sector size (512,1024,2048 or 4096) */</span> 29 <span class="k">#endif</span> 30 <span class="k">#if</span> FF_FS_EXFAT 31 BYTE* dirbuf; <span class="c">/* Directory entry block scratchpad buffer */</span> 32 <span class="k">#endif</span> 33 <span class="k">#if</span> FF_FS_REENTRANT 34 FF_SYNC_t sobj; <span class="c">/* Identifier of sync object */</span> 35 <span class="k">#endif</span> 36 <span class="k">#if</span> !FF_FS_READONLY 37 DWORD last_clust; <span class="c">/* FSINFO: Last allocated cluster (0xFFFFFFFF if invalid) */</span> 38 DWORD free_clust; <span class="c">/* FSINFO: Number of free clusters (0xFFFFFFFF if invalid) */</span> 39 <span class="k">#endif</span> 40 <span class="k">#if</span> FF_FS_RPATH 41 DWORD cdir; <span class="c">/* Cluster number of current directory (0:root) */</span> 42 <span class="k">#if</span> FF_FS_EXFAT 43 DWORD cdc_scl; <span class="c">/* Containing directory start cluster (invalid when cdir is 0) */</span> 44 DWORD cdc_size; <span class="c">/* b31-b8:Size of containing directory, b7-b0: Chain status */</span> 45 DWORD cdc_ofs; <span class="c">/* Offset in the containing directory (invalid when cdir is 0) */</span> 46 <span class="k">#endif</span> 47 <span class="k">#endif</span> 48 DWORD n_fatent; <span class="c">/* Number of FAT entries (Number of clusters + 2) */</span> 49 DWORD fsize; <span class="c">/* Sectors per FAT */</span> 50 LBA_t volbase; <span class="c">/* Volume base LBA */</span> 51 LBA_t fatbase; <span class="c">/* FAT base LBA */</span> 52 LBA_t dirbase; <span class="c">/* Root directory base (LBA|Cluster) */</span> 53 LBA_t database; <span class="c">/* Data base LBA */</span> 54 LBA_t winsect; <span class="c">/* Sector LBA appearing in the win[] */</span> 55 BYTE win[FF_MAX_SS]; <span class="c">/* Disk access window for directory, FAT (and file data at tiny cfg) */</span> 56 } FATFS; 57 </pre> 58 </div> 59 60 <p class="foot"><a href="../00index_e.html">Return</a></p> 61 </body> 62 </html>