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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html><head><meta http-equiv="Content-Type" content="text/html;charset=iso-8859-1"><title>Procyon ARMlib-LPC2100: fat.c Source File</title><link href="dox.css" rel="stylesheet" type="text/css"></head><body><!-- Generated by Doxygen 1.3.6 --><div class="qindex"><a class="qindex" href="main.html">Main Page</a> | <a class="qindex" href="files.html">File List</a> | <a class="qindex" href="globals.html">Globals</a></div><h1>fat.c</h1><a href="fat_8c.html">Go to the documentation of this file.</a><div class="fragment"><pre>00001 <span class="comment">/*! \file fat.c \brief FAT16/32 file system driver. */</span>00002 <span class="comment">//*****************************************************************************</span>00003 <span class="comment">//</span>00004 <span class="comment">// File Name : 'fat.c'</span>00005 <span class="comment">// Title : FAT16/32 file system driver</span>00006 <span class="comment">// Author : Pascal Stang</span>00007 <span class="comment">// Date : 11/07/2000</span>00008 <span class="comment">// Revised : 12/12/2000</span>00009 <span class="comment">// Version : 0.3</span>00010 <span class="comment">// Target MCU : ATmega103 (should work for Atmel AVR Series)</span>00011 <span class="comment">// Editor Tabs : 4</span>00012 <span class="comment">//</span>00013 <span class="comment">// This code is based in part on work done by Jesper Hansen for his</span>00014 <span class="comment">// YAMPP MP3 player project.</span>00015 <span class="comment">//</span>00016 <span class="comment">// NOTE: This code is currently below version 1.0, and therefore is considered</span>00017 <span class="comment">// to be lacking in some functionality or documentation, or may not be fully</span>00018 <span class="comment">// tested. Nonetheless, you can expect most functions to work.</span>00019 <span class="comment">//</span>00020 <span class="comment">// This code is distributed under the GNU Public License</span>00021 <span class="comment">// which can be found at http://www.gnu.org/licenses/gpl.txt</span>00022 <span class="comment">//</span>00023 <span class="comment">//*****************************************************************************</span>00024 00025 00026 <span class="preprocessor">#include <string.h></span>00027 00028 <span class="preprocessor">#include "<a class="code" href="ata_8h.html">ata.h</a>"</span>00029 <span class="preprocessor">#include "<a class="code" href="rprintf_8h.html">rprintf.h</a>"</span>00030 <span class="preprocessor">#include "<a class="code" href="debug_8h.html">debug.h</a>"</span>00031 00032 <span class="preprocessor">#include "<a class="code" href="fat_8h.html">fat.h</a>"</span>00033 <span class="preprocessor">#include "fatconf.h"</span>00034 00035 <span class="comment">// globals</span>00036 <span class="comment">// buffers</span>00037 <span class="keywordtype">unsigned</span> <span class="keywordtype">char</span> *SectorBuffer = (<span class="keywordtype">unsigned</span> <span class="keywordtype">char</span> *) FAT_SECTOR_BUFFER_ADDR;00038 <span class="keywordtype">unsigned</span> <span class="keywordtype">char</span> *FileNameBuffer = (<span class="keywordtype">unsigned</span> <span class="keywordtype">char</span> *) FAT_FILENAME_BUFFER_ADDR;00039 <span class="keywordtype">unsigned</span> <span class="keywordtype">char</span> *PathNameBuffer = (<span class="keywordtype">unsigned</span> <span class="keywordtype">char</span> *) FAT_PATHNAME_BUFFER_ADDR;00040 00041 <span class="comment">// filesystem constants/metrics</span>00042 <span class="keyword">struct </span>partrecord PartInfo;00043 <span class="keywordtype">unsigned</span> <span class="keywordtype">char</span> Fat32Enabled;00044 <span class="keywordtype">unsigned</span> <span class="keywordtype">long</span> FirstDataSector;00045 <span class="keywordtype">unsigned</span> <span class="keywordtype">short</span> BytesPerSector;00046 <span class="keywordtype">unsigned</span> <span class="keywordtype">short</span> SectorsPerCluster;00047 <span class="keywordtype">unsigned</span> <span class="keywordtype">long</span> FirstFATSector;00048 <span class="keywordtype">unsigned</span> <span class="keywordtype">long</span> RootDirStartCluster;00049 00050 <span class="comment">// operating variables</span>00051 <span class="keywordtype">unsigned</span> <span class="keywordtype">long</span> CurrentDirStartCluster; <span class="comment">//< current directory starting cluster</span>00052 <span class="keyword">struct </span>FileInfoStruct FileInfo; <span class="comment">//< file information for last file accessed</span>00053 <span class="keywordtype">unsigned</span> <span class="keywordtype">long</span> FatInCache = 0;00054 00055 00056 <span class="comment">/*************************************************************************/</span>00057 <span class="comment">/*************************************************************************/</span>00058 00059 00060 <span class="keywordtype">unsigned</span> <span class="keywordtype">long</span> fatClustToSect(<span class="keywordtype">unsigned</span> <span class="keywordtype">long</span> clust)00061 {00062 <span class="keywordflow">return</span> ((clust-2) * SectorsPerCluster) + FirstDataSector;00063 }00064 00065 <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> fatClusterSize(<span class="keywordtype">void</span>)00066 {00067 <span class="comment">// return the number of sectors in a disk cluster</span>00068 <span class="keywordflow">return</span> SectorsPerCluster;00069 }00070 00071 <span class="keywordtype">unsigned</span> <span class="keywordtype">char</span> fatInit( <span class="keywordtype">unsigned</span> <span class="keywordtype">char</span> device)00072 {00073 <span class="comment">//struct partrecord *pr;</span>00074 <span class="keyword">struct </span>bpb710 *bpb;00075 00076 <span class="comment">// read partition table</span>00077 <span class="comment">// TODO.... error checking</span>00078 ataReadSectors(DRIVE0, 0, 1, SectorBuffer);00079 <span class="comment">// map first partition record </span>00080 <span class="comment">// save partition information to global PartInfo</span>00081 PartInfo = *((<span class="keyword">struct </span>partrecord *) ((<span class="keyword">struct </span>partsector *) SectorBuffer)->psPart);00082 <span class="comment">// PartInfo = *pr;</span>00083 00084 <span class="comment">// Read the Partition BootSector</span>00085 <span class="comment">// **first sector of partition in PartInfo.prStartLBA</span>00086 ataReadSectors( DRIVE0, PartInfo.prStartLBA, 1, SectorBuffer );00087 bpb = (<span class="keyword">struct </span>bpb710 *) ((<span class="keyword">struct </span>bootsector710 *) SectorBuffer)->bsBPB;00088 00089 <span class="comment">// setup global disk constants</span>00090 FirstDataSector = PartInfo.prStartLBA;00091 <span class="keywordflow">if</span>(bpb->bpbFATsecs)00092 {00093 <span class="comment">// bpbFATsecs is non-zero and is therefore valid</span>00094 FirstDataSector += bpb->bpbResSectors + bpb->bpbFATs * bpb->bpbFATsecs;00095 }00096 <span class="keywordflow">else</span>00097 {00098 <span class="comment">// bpbFATsecs is zero, real value is in bpbBigFATsecs</span>00099 FirstDataSector += bpb->bpbResSectors + bpb->bpbFATs * bpb->bpbBigFATsecs;00100 }00101 SectorsPerCluster = bpb->bpbSecPerClust;00102 BytesPerSector = bpb->bpbBytesPerSec;00103 FirstFATSector = bpb->bpbResSectors + PartInfo.prStartLBA;00104 00105 <span class="keywordflow">switch</span> (PartInfo.prPartType)00106 {00107 <span class="keywordflow">case</span> PART_TYPE_DOSFAT16:00108 <span class="keywordflow">case</span> PART_TYPE_FAT16:00109 <span class="keywordflow">case</span> PART_TYPE_FAT16LBA:00110 <span class="comment">// first directory cluster is 2 by default (clusters range 2->big)</span>00111 RootDirStartCluster = CLUST_FIRST;00112 <span class="comment">// push data sector pointer to end of root directory area</span>00113 <span class="comment">//FirstDataSector += (bpb->bpbRootDirEnts)/DIRENTRIES_PER_SECTOR;</span>00114 Fat32Enabled = FALSE;00115 <span class="keywordflow">break</span>;00116 <span class="keywordflow">case</span> PART_TYPE_FAT32LBA:00117 <span class="keywordflow">case</span> PART_TYPE_FAT32:00118 <span class="comment">// bpbRootClust field exists in FAT32 bpb710, but not in lesser bpb's</span>00119 RootDirStartCluster = bpb->bpbRootClust;00120 <span class="comment">// push data sector pointer to end of root directory area</span>00121 <span class="comment">// need this? FirstDataSector += (bpb->bpbRootDirEnts)/DIRENTRIES_PER_SECTOR;</span>00122 Fat32Enabled = TRUE;00123 <span class="keywordflow">break</span>;00124 <span class="keywordflow">default</span>:00125 <a class="code" href="rprintf_8h.html#a8">rprintfStr</a>(<span class="stringliteral">"Found: No Partition!\r\n"</span>);00126 <span class="comment">//return 1;</span>00127 <span class="keywordflow">break</span>;00128 }00129 00130 <span class="comment">// set current directory to root (\)</span>00131 CurrentDirStartCluster = RootDirStartCluster;00132 PathNameBuffer[0] = <span class="charliteral">'\\'</span>;00133 PathNameBuffer[1] = 0;00134 00135 00136 <span class="comment">// do debug</span>00137 <span class="preprocessor">#ifdef DEBUG_FAT</span>00138 <span class="preprocessor"></span> <span class="keywordflow">switch</span> (PartInfo.prPartType)00139 {00140 <span class="keywordflow">case</span> PART_TYPE_DOSFAT16:00141 <a class="code" href="rprintf_8h.html#a8">rprintfStr</a>(<span class="stringliteral">"Found: DOSFAT 16\r\n"</span>);00142 <span class="keywordflow">break</span>;00143 <span class="keywordflow">case</span> PART_TYPE_FAT16:00144 <a class="code" href="rprintf_8h.html#a8">rprintfStr</a>(<span class="stringliteral">"Found: FAT16\r\n"</span>);00145 <span class="keywordflow">break</span>;00146 <span class="keywordflow">case</span> PART_TYPE_FAT16LBA:00147 <a class="code" href="rprintf_8h.html#a8">rprintfStr</a>(<span class="stringliteral">"Found: FAT16 LBA\r\n"</span>);00148 <span class="keywordflow">break</span>;00149 <span class="keywordflow">case</span> PART_TYPE_FAT32LBA:00150 <a class="code" href="rprintf_8h.html#a8">rprintfStr</a>(<span class="stringliteral">"Found: FAT32 LBA\r\n"</span>);00151 <span class="keywordflow">break</span>;00152 <span class="keywordflow">case</span> PART_TYPE_FAT32:00153 <a class="code" href="rprintf_8h.html#a8">rprintfStr</a>(<span class="stringliteral">"Found: FAT32\r\n"</span>);00154 <span class="comment">//return 1; </span>00155 <span class="keywordflow">break</span>;00156 <span class="keywordflow">default</span>:00157 <a class="code" href="rprintf_8h.html#a8">rprintfStr</a>(<span class="stringliteral">"Found: No Partition!\r\n"</span>);00158 <span class="comment">//return 1;</span>⌨️ 快捷键说明
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