fat_8c-source.html

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00183     
00184     <span class="keywordflow">if</span>(count == 0)
00185     {
00186         entrycount = 0;
00187         DirNameBuffer = 0;
00188     }
00189     
00190     <span class="comment">// read dir data</span>
00191     sector = fatClustToSect(FirstDirSector);
00192 
00193     hasBuffer = 0;
00194 
00195     index = 16; <span class="comment">// crank it up</span>
00196     <span class="keywordflow">do</span> 
00197     {
00198         <span class="keywordflow">if</span>(index == 16) <span class="comment">// time for next sector ?</span>
00199         {
00200             ataReadSectors( DRIVE0, sector++, 1, SectorBuffer);
00201             de = (<span class="keyword">struct </span>direntry *) SectorBuffer;
00202             index = 0;
00203         }   
00204     
00205         <span class="keywordflow">if</span>(*de-&gt;deName != 0xE5)
00206         {
00207             <span class="comment">// if not a deleted entry</span>
00208             <span class="keywordflow">if</span>(de-&gt;deAttributes == ATTR_LONG_FILENAME)
00209             {
00210                 <span class="comment">// we have a long name entry</span>
00211                 we = (<span class="keyword">struct </span>winentry *) de;
00212                 b = 13 *( (we-&gt;weCnt-1) &amp; 0x0f);                <span class="comment">// index into string</span>
00213                 p = &amp;LongNameBuffer[b];
00214                 <span class="keywordflow">for</span> (i=0;i&lt;5;i++)   *p++ = we-&gt;wePart1[i*2];    <span class="comment">// copy first part          </span>
00215                 <span class="keywordflow">for</span> (i=0;i&lt;6;i++)   *p++ = we-&gt;wePart2[i*2];    <span class="comment">// second part</span>
00216                 <span class="keywordflow">for</span> (i=0;i&lt;2;i++)   *p++ = we-&gt;wePart3[i*2];    <span class="comment">// and third part</span>
00217                 <span class="keywordflow">if</span> (we-&gt;weCnt &amp; 0x40) *p = 0;                   <span class="comment">// in case dirnamelength is multiple of 13</span>
00218                 if ((we-&gt;weCnt &amp; 0x0f) == 1) hasBuffer = 1;     <span class="comment">// mark that we have a long entry</span>
00219             }
00220             <span class="keywordflow">else</span>
00221             {
00222                 <span class="comment">// we have a short name entry</span>
00223                 <span class="comment">// check if this is the end of a multi-part long name entry</span>
00224                 <span class="keywordflow">if</span>(hasBuffer)
00225                 {
00226                     <span class="comment">// a long entry name has been collected</span>
00227                     <span class="comment">// is it a directory ?</span>
00228                     <span class="keywordflow">if</span>(de-&gt;deAttributes == ATTR_DIRECTORY)
00229                     {
00230                         <span class="keywordtype">unsigned</span> <span class="keywordtype">long</span> save = FirstDirSector;
00231                         <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> save2 = baseentry;
00232                         <span class="keywordtype">unsigned</span> <span class="keywordtype">long</span> rval;
00233                         
00234                         strcpy(DirNameBuffer,LongNameBuffer);
00235                         strcat(DirNameBuffer,<span class="stringliteral">"/"</span>);
00236 
00237 <span class="comment">//                      rprintfStr(LongNameBuffer); rprintfProgStrM("/"); //EOL();</span>
00238 
00239                         <span class="comment">// call recursively</span>
00240                         FirstDirSector = ((<span class="keywordtype">unsigned</span> long)de-&gt;deHighClust &lt;&lt; 16) + de-&gt;deStartCluster;
00241                         rval = fatGetDirEntry(entry,1);
00242                         FirstDirSector = save;
00243                         baseentry = save2;
00244                         <span class="keywordflow">if</span> (rval)
00245                             <span class="keywordflow">return</span> rval;
00246                         <span class="keywordflow">else</span>    
00247                         {
00248                             <span class="comment">// reload original sector</span>
00249                             ataReadSectors( DRIVE0, sector-1, 1, SectorBuffer);
00250                             entrycount--;           <span class="comment">// decrement entry counter      </span>
00251                             *DirNameBuffer = 0;
00252                     }
00253                     }
00254                     <span class="keywordflow">else</span> <span class="comment">// normal file entry</span>
00255                         <span class="keywordflow">if</span>(entrycount == entry)     
00256                             <span class="keywordflow">break</span>;
00257                     hasBuffer = 0;  <span class="comment">// clear buffer </span>
00258                     entrycount++;   <span class="comment">// increment entry counter      </span>
00259                 }
00260                 <span class="comment">// else ignore short_name_only entries</span>
00261             }
00262         }
00263         de++;
00264         index++;
00265     }   <span class="keywordflow">while</span> (*de-&gt;deName || index == 16); <span class="comment">// 0 in de-&gt;deName[0] if no more entries</span>
00266 
00267     <span class="keywordflow">if</span> (hasBuffer == 0)     <span class="comment">// end of entries</span>
00268         <span class="keywordflow">return</span> 0;
00269     
00270     FileSize = de-&gt;deFileSize;
00271     <span class="keywordflow">return</span> (<span class="keywordtype">unsigned</span> <span class="keywordtype">long</span>) ((<span class="keywordtype">unsigned</span> long)de-&gt;deHighClust &lt;&lt; 16) + de-&gt;deStartCluster;
00272 }
00273 
00274 
00275 <span class="comment">// return the size of the last directory entry</span>
00276 <span class="keywordtype">unsigned</span> <span class="keywordtype">long</span> fatGetFilesize(<span class="keywordtype">void</span>)
00277 {
00278     <span class="keywordflow">return</span> FileSize;
00279 }
00280 
00281 
00282 <span class="comment">// return the long name of the last directory entry</span>
00283 <span class="keywordtype">char</span>* fatGetFilename(<span class="keywordtype">void</span>)
00284 {   
00285     <span class="keywordflow">return</span> LongNameBuffer;
00286 }
00287 
00288 
00289 <span class="comment">// return the directory of the last directory entry</span>
00290 <span class="keywordtype">char</span>* fatGetDirname(<span class="keywordtype">void</span>)
00291 {   
00292     <span class="keywordflow">return</span> DirNameBuffer;
00293 }
00294 
00295 
00296 <span class="comment">// load a clusterfull of data</span>
00297 <span class="keywordtype">void</span> fatLoadCluster(<span class="keywordtype">unsigned</span> <span class="keywordtype">long</span> cluster, <span class="keywordtype">unsigned</span> <span class="keywordtype">char</span> *buffer)
00298 {
00299     <span class="keyword">register</span> <span class="keywordtype">unsigned</span> <span class="keywordtype">char</span> i;
00300     <span class="comment">// read cluster</span>
00301     <span class="comment">//while ( ataReadSectors( DRIVE0, clust2sect(cluster), SectorsPerCluster, buffer) != 0);</span>
00302     <span class="keywordflow">for</span>(i=0; i&lt;SectorsPerCluster; i++)
00303     {
00304 <span class="comment">//      ataReadSectors( DRIVE0, clust2sect(cluster)+i, 1, buffer+(i&lt;&lt;9) );</span>
00305         <span class="comment">// temporary fix for wierd misaligned cluster problem</span>
00306         <span class="comment">// (only when using FAT16?)</span>
00307         ataReadSectors( DRIVE0, fatClustToSect(cluster+8)+i, 1, buffer+(i&lt;&lt;9) );
00308     }
00309 }
00310 
00311 
00312 <span class="comment">// find next cluster in the FAT chain</span>
00313 <span class="keywordtype">unsigned</span> <span class="keywordtype">long</span> fatNextCluster(<span class="keywordtype">unsigned</span> <span class="keywordtype">long</span> cluster)
00314 {
00315     <span class="keywordtype">unsigned</span> <span class="keywordtype">long</span> nextCluster;
00316     <span class="keywordtype">unsigned</span> <span class="keywordtype">long</span> fatMask;
00317     <span class="keywordtype">unsigned</span> <span class="keywordtype">long</span> fatOffset;
00318     <span class="keywordtype">unsigned</span> <span class="keywordtype">long</span> sector;
00319     <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> offset;
00320     
00321     <span class="comment">// get fat offset in bytes</span>
00322     <span class="keywordflow">if</span>(Fat32Enabled)
00323     {
00324         <span class="comment">// four FAT bytes (32 bits) for every cluster</span>
00325         fatOffset = cluster &lt;&lt; 2;
00326         <span class="comment">// set the FAT bit mask</span>
00327         fatMask = FAT32_MASK;
00328     }
00329     <span class="keywordflow">else</span>
00330     {
00331         <span class="comment">// two FAT bytes (16 bits) for every cluster</span>
00332         fatOffset = cluster &lt;&lt; 1;
00333         <span class="comment">// set the FAT bit mask</span>
00334         fatMask = FAT16_MASK;
00335     }
00336     
00337     <span class="comment">// calculate the FAT sector that we're interested in</span>
00338     sector = FirstFATSector + (fatOffset / BytesPerSector);
00339     <span class="comment">// calculate offset of the our entry within that FAT sector</span>
00340     offset = fatOffset % BytesPerSector;
00341 
00342     <span class="comment">// if we don't already have this FAT chunk loaded, go get it</span>
00343     <span class="keywordflow">if</span> (sector != FatInCache)
00344     {
00345         <span class="comment">// read sector of FAT table</span>
00346         <span class="keywordflow">while</span> (ataReadSectors( DRIVE0, sector, 1, (<span class="keywordtype">unsigned</span> <span class="keywordtype">char</span>*)FAT_CACHE_ADDR) != 0);
00347         FatInCache = sector;
00348     }
00349 
00350     <span class="comment">// read the nextCluster value</span>
00351     nextCluster = (*((<span class="keywordtype">unsigned</span> <span class="keywordtype">long</span>*) &amp;((<span class="keywordtype">char</span>*)FAT_CACHE_ADDR)[offset])) &amp; fatMask;
00352 
00353     <span class="comment">// check to see if we're at the end of the chain</span>
00354     <span class="keywordflow">if</span> (nextCluster == (CLUST_EOFE &amp; fatMask))
00355         nextCluster = 0;
00356 
00357 <span class="preprocessor">#ifdef DEBUG_FAT</span>
00358 <span class="preprocessor"></span>    <a class="code" href="group__rprintf.html#ga15">rprintfProgStrM</a>(<span class="stringliteral">"&gt;"</span>);
00359     <a class="code" href="group__rprintf.html#ga9">rprintfu32</a>(nextCluster);
00360     <a class="code" href="group__rprintf.html#ga5">rprintfCRLF</a>();
00361 <span class="preprocessor">#endif</span>
00362 <span class="preprocessor"></span>    
00363     <span class="keywordflow">return</span> nextCluster;
00364 }
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