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="stylesheet" href="../css_e.css" type="text/css" media="screen" title="ELM Default"> 7<title>FatFs - FATFS</title> 8</head> 9 10<body> 11 12<div class="para"> 13<h2>FATFS</h2> 14<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> 15<pre> 16<span class="k">typedef</span> <span class="k">struct</span> { 17 BYTE fs_type; <span class="c">/* FAT type (0, FS_FAT12, FS_FAT16, FS_FAT32 or FS_EXFAT) */</span> 18 BYTE pdrv; <span class="c">/* Hosting physical drive of this volume */</span> 19 BYTE n_fats; <span class="c">/* Number of FAT copies (1,2) */</span> 20 BYTE wflag; <span class="c">/* win[] flag (b0:win[] is dirty) */</span> 21 BYTE fsi_flag; <span class="c">/* FSINFO flags (b7:Disabled, b0:Dirty) */</span> 22 WORD id; <span class="c">/* Volume mount ID */</span> 23 WORD n_rootdir; <span class="c">/* Number of root directory entries (FAT12/16) */</span> 24 WORD csize; <span class="c">/* Sectors per cluster */</span> 25<span class="k">#if</span> FF_MAX_SS != FF_MIN_SS 26 WORD ssize; <span class="c">/* Sector size (512,1024,2048 or 4096) */</span> 27<span class="k">#endif</span> 28<span class="k">#if</span> FF_FS_EXFAT 29 BYTE* dirbuf; <span class="c">/* Directory entry block scratchpad buffer */</span> 30<span class="k">#endif</span> 31<span class="k">#if</span> FF_FS_REENTRANT 32 FF_SYNC_t sobj; <span class="c">/* Identifier of sync object */</span> 33<span class="k">#endif</span> 34<span class="k">#if</span> !FF_FS_READONLY 35 DWORD last_clust; <span class="c">/* FSINFO: Last allocated cluster (0xFFFFFFFF if invalid) */</span> 36 DWORD free_clust; <span class="c">/* FSINFO: Number of free clusters (0xFFFFFFFF if invalid) */</span> 37<span class="k">#endif</span> 38<span class="k">#if</span> FF_FS_RPATH 39 DWORD cdir; <span class="c">/* Cluster number of current directory (0:root) */</span> 40<span class="k">#if</span> FF_FS_EXFAT 41 DWORD cdc_scl; <span class="c">/* Containing directory start cluster (invalid when cdir is 0) */</span> 42 DWORD cdc_size; <span class="c">/* b31-b8:Size of containing directory, b7-b0: Chain status */</span> 43 DWORD cdc_ofs; <span class="c">/* Offset in the containing directory (invalid when cdir is 0) */</span> 44<span class="k">#endif</span> 45<span class="k">#endif</span> 46 DWORD n_fatent; <span class="c">/* Number of FAT entries (Number of clusters + 2) */</span> 47 DWORD fsize; <span class="c">/* Sectors per FAT */</span> 48 LBA_t volbase; <span class="c">/* Volume base LBA */</span> 49 LBA_t fatbase; <span class="c">/* FAT base LBA */</span> 50 LBA_t dirbase; <span class="c">/* Root directory base (LBA|Cluster) */</span> 51 LBA_t database; <span class="c">/* Data base LBA */</span> 52 LBA_t winsect; <span class="c">/* Sector LBA appearing in the win[] */</span> 53 BYTE win[FF_MAX_SS]; <span class="c">/* Disk access window for directory, FAT (and file data at tiny cfg) */</span> 54} FATFS; 55</pre> 56</div> 57 58<p class="foot"><a href="../00index_e.html">Return</a></p> 59</body> 60</html> 61