filesys_8c-source.html

MP3播放器源代码, VS1003B

00452     }<span class="keywordflow">else</span>{ <span class="comment">//FAT32</span>
00453       next.<a class="code" href="unionAddress.html#o0">l</a> = <a class="code" href="buffer_8c.html#a0">diskSect</a>.<a class="code" href="unionDiskBlock.html#o4">Fat32Table</a>[entryNumber]&amp;0x0fffffff;
00454     }
00455     <span class="comment">/* next.l is the FAT entry (next cluster number) */</span>
00456     
00457     
00458     ConsoleWrite(<span class="stringliteral">"\rFragment start: cluster "</span>);
00459     ConsolePutUInt(<span class="keyword">this</span>.l);
00460     ConsoleWrite(<span class="stringliteral">"sector "</span>);
00461     ConsolePutUInt(<a class="code" href="filesys_8c.html#a6">fragment</a>[c].start);
00462 
00463     <span class="keywordflow">while</span> (next.<a class="code" href="unionAddress.html#o0">l</a>==(<span class="keyword">this</span>.l+1)){
00464       <span class="comment">//Not a fragment break -- continue to next entry </span>
00465 
00466       <span class="comment">//in this temp.l is used only to allow compiler memory spilling to temp</span>
00467       <a class="code" href="board_8c.html#a0">temp</a>.<a class="code" href="unionTemp.html#o2">l</a> = <a class="code" href="filesys_8c.html#a6">fragment</a>[c].<a class="code" href="structfragmentEntry.html#o1">length</a>;
00468       <a class="code" href="board_8c.html#a0">temp</a>.<a class="code" href="unionTemp.html#o2">l</a> += <a class="code" href="filesys_8c.html#a5">fatSectorsPerCluster</a>;
00469       <a class="code" href="filesys_8c.html#a6">fragment</a>[c].<a class="code" href="structfragmentEntry.html#o1">length</a> = <a class="code" href="board_8c.html#a0">temp</a>.<a class="code" href="unionTemp.html#o2">l</a>;
00470 
00471       entryNumber++;
00472 
00473       <span class="comment">// --- Check for a page break</span>
00474       <span class="keywordflow">if</span> (entryNumber==0){ <span class="comment">//entryNumber has rolled over!!!! (8bit char)</span>
00475         <span class="comment">//FAT16 table page border is reached</span>
00476         fatSector.<a class="code" href="unionAddress.html#o0">l</a>++; <span class="comment">//Advance to next page;</span>
00477         entryNumber=0;
00478         <a class="code" href="storage_8h.html#a2">ReadDiskSector</a>(fatSector.<a class="code" href="unionAddress.html#o0">l</a>);
00479       }
00480       <span class="keywordflow">if</span> (<a class="code" href="filesys_8h.html#a0">IS_FAT_32</a> &amp;&amp; (entryNumber==128)){
00481         <span class="comment">//FAT32 table page border is reached</span>
00482         fatSector.<a class="code" href="unionAddress.html#o0">l</a>++;
00483         entryNumber=0;
00484         <a class="code" href="storage_8h.html#a2">ReadDiskSector</a>(fatSector.<a class="code" href="unionAddress.html#o0">l</a>);
00485       }
00486       
00487       <span class="comment">// --- Advance to next cluster</span>
00488       <span class="keyword">this</span>.l = next.<a class="code" href="unionAddress.html#o0">l</a>;
00489       
00490       <span class="keywordflow">if</span> (!<a class="code" href="filesys_8h.html#a0">IS_FAT_32</a>){
00491         <span class="comment">//FAT16 get next cluster n</span>
00492         next.<a class="code" href="unionAddress.html#o0">l</a> = <a class="code" href="buffer_8c.html#a0">diskSect</a>.<a class="code" href="unionDiskBlock.html#o3">Fat16Table</a>[entryNumber];       
00493         <span class="keywordflow">if</span> ((next.<a class="code" href="unionAddress.html#o1">b</a>.<a class="code" href="structAddress_1_1B.html#o1">b1</a>==0xff)&amp;&amp;(next.<a class="code" href="unionAddress.html#o1">b</a>.<a class="code" href="structAddress_1_1B.html#o0">b0</a>==0xff)){
00494           <span class="comment">//FAT16 end-of-file</span>
00495           next.<a class="code" href="unionAddress.html#o1">b</a>.<a class="code" href="structAddress_1_1B.html#o3">b3</a> = 0xff; <span class="comment">//mark end-of-file (FAT32 compatible)</span>
00496         }
00497       }<span class="keywordflow">else</span>{
00498         <span class="comment">//FAT32 get next cluster n</span>
00499         next.<a class="code" href="unionAddress.html#o0">l</a> = <a class="code" href="buffer_8c.html#a0">diskSect</a>.<a class="code" href="unionDiskBlock.html#o4">Fat32Table</a>[entryNumber];
00500       }
00501     }<span class="comment">//This repeats until there is a discontinuity</span>
00502     
00503     <span class="comment">/* next.l now has the cluster entry for last cluster in fragment</span>
00504 <span class="comment">       it has a high value if eof (see FAT spec) */</span>
00505 
00506     
00507     ConsoleWrite(<span class="stringliteral">"Size: "</span>);
00508     ConsolePutUInt(<a class="code" href="filesys_8c.html#a6">fragment</a>[c].length);
00509     ConsoleWrite(<span class="stringliteral">"sectors."</span>);
00510 
00511     <span class="comment">//EOF test</span>
00512     <span class="keywordflow">if</span> ((next.<a class="code" href="unionAddress.html#o1">b</a>.<a class="code" href="structAddress_1_1B.html#o3">b3</a>&amp;0x08) <span class="comment">//Quick test</span>
00513         &amp;&amp; ((next.<a class="code" href="unionAddress.html#o0">l</a>&gt;0x0ffffff0) | !<a class="code" href="filesys_8h.html#a0">IS_FAT_32</a>)){ <span class="comment">//Complete test</span>
00514       <span class="comment">//EOF</span>
00515       ConsoleWrite(<span class="stringliteral">" &lt;EOF&gt;\r"</span>);
00516       <a class="code" href="buffer_8c.html#a2">sectorAddress</a>.<a class="code" href="unionAddress.html#o1">b</a>.<a class="code" href="structAddress_1_1B.html#o3">b3</a> = 0xff;
00517     }<span class="keywordflow">else</span>{
00518       
00519       <span class="comment">//Determine next physical sector for next fragment</span>
00520       <a class="code" href="buffer_8c.html#a2">sectorAddress</a>.<a class="code" href="unionAddress.html#o0">l</a> = next.<a class="code" href="unionAddress.html#o0">l</a>;
00521       <a class="code" href="buffer_8c.html#a2">sectorAddress</a>.<a class="code" href="unionAddress.html#o0">l</a> *= <a class="code" href="filesys_8c.html#a5">fatSectorsPerCluster</a>;
00522       <a class="code" href="buffer_8c.html#a2">sectorAddress</a>.<a class="code" href="unionAddress.html#o0">l</a> += <a class="code" href="filesys_8c.html#a4">dataStart</a>;
00523     }
00524     
00525     c++; <span class="comment">//Advance to next fragment number</span>
00526     
00527     <span class="keywordflow">if</span> (c==<a class="code" href="filesys_8c.html#a0">MAX_NUMBER_FRAGMENTS</a>){
00528       <span class="comment">//End of RAM space allocated for fragment table</span>
00529       <span class="comment">//Force end-of-file</span>
00530       <a class="code" href="buffer_8c.html#a2">sectorAddress</a>.<a class="code" href="unionAddress.html#o1">b</a>.<a class="code" href="structAddress_1_1B.html#o3">b3</a>=0xff;
00531     }
00532     
00533   }<span class="comment">//break or continue to next cluster</span>
00534   
00535   <span class="keywordflow">return</span> c; <span class="comment">//Return number of fragments;</span>
00536 }
00537 
00538 
00539 
<a name="l00541"></a><a class="code" href="filesys_8c.html#a20">00541</a> <span class="keywordtype">unsigned</span> <span class="keywordtype">char</span> <a class="code" href="filesys_8c.html#a20">LoadNextSector</a>(){
00542   <a class="code" href="buffer_8c.html#a2">sectorAddress</a>.<a class="code" href="unionAddress.html#o0">l</a> = <a class="code" href="filesys_8c.html#a18">GetNextSector</a>(<a class="code" href="buffer_8c.html#a2">sectorAddress</a>.<a class="code" href="unionAddress.html#o0">l</a>);
00543   <span class="keywordflow">if</span> (<a class="code" href="buffer_8c.html#a2">sectorAddress</a>.<a class="code" href="unionAddress.html#o1">b</a>.<a class="code" href="structAddress_1_1B.html#o1">b1</a> &amp; 0x80){
00545     <span class="keywordflow">return</span> 0x0d; <span class="comment">/*EOF*/</span>
00546   }
00547   <span class="keywordflow">if</span> (<a class="code" href="storage_8h.html#a2">ReadDiskSector</a>(<a class="code" href="buffer_8c.html#a2">sectorAddress</a>.<a class="code" href="unionAddress.html#o0">l</a>)){
00548     <span class="keywordflow">return</span> 0x0d; <span class="comment">/*EOF*/</span>
00549   }
00550   <span class="keywordflow">return</span> 0; <span class="comment">/* All OK return */</span>
00551 }
00552   
<a name="l00561"></a><a class="code" href="filesys_8h.html#a9">00561</a> <a class="code" href="board_8h.html#a47">Public</a> <span class="keywordtype">unsigned</span> <span class="keywordtype">char</span> <a class="code" href="filesys_8c.html#a21">FGetChar</a>(){
00562 
00563   <span class="keywordflow">if</span> (!<a class="code" href="filesys_8c.html#a7">fileSize</a>) <span class="keywordflow">return</span> 0; <span class="comment">//return 0 for end-of-file</span>
00564 
00565   <span class="keywordflow">if</span> (<a class="code" href="buffer_8c.html#a1">dataBufPtr</a>==0){
00566     <span class="comment">/* A file has been opened but not read from yet, so read the first</span>
00567 <span class="comment">       sector. */</span>
00568     <a class="code" href="storage_8h.html#a2">ReadDiskSector</a>(<a class="code" href="buffer_8c.html#a2">sectorAddress</a>.<a class="code" href="unionAddress.html#o0">l</a>);
00569     <a class="code" href="buffer_8c.html#a1">dataBufPtr</a> = <a class="code" href="buffer_8c.html#a0">diskSect</a>.<a class="code" href="unionDiskBlock.html#o1">raw</a>.<a class="code" href="structDiskBlock_1_1Raw.html#o0">buf</a>;
00570   }
00571 
00572   <span class="keywordflow">if</span> (<a class="code" href="buffer_8c.html#a1">dataBufPtr</a>&gt;<a class="code" href="buffer_8c.html#a0">diskSect</a>.<a class="code" href="unionDiskBlock.html#o1">raw</a>.<a class="code" href="structDiskBlock_1_1Raw.html#o0">buf</a>+511){
00573     <span class="comment">/* An end of sector has been reached, read the next sector */</span>    
00574     <span class="keywordflow">if</span> (<a class="code" href="filesys_8c.html#a20">LoadNextSector</a>()){
00575       <span class="comment">/* Error, end-of-file according to FAT records */</span>
00576       <span class="keywordflow">return</span> 0; <span class="comment">/* must return something */</span>
00577     }
00578     <a class="code" href="buffer_8c.html#a1">dataBufPtr</a>=<a class="code" href="buffer_8c.html#a0">diskSect</a>.<a class="code" href="unionDiskBlock.html#o1">raw</a>.<a class="code" href="structDiskBlock_1_1Raw.html#o0">buf</a>;
00579   }
00580 
00581   <span class="comment">/* Everything should now be ok for reading a byte. */</span>
00582 
00583   <a class="code" href="filesys_8c.html#a7">fileSize</a>--;
00584   <span class="keywordflow">return</span> (*<a class="code" href="buffer_8c.html#a1">dataBufPtr</a>++);
00585 }
00586 
00587 
00588 
<a name="l00610"></a><a class="code" href="filesys_8h.html#a8">00610</a> <a class="code" href="board_8h.html#a47">Public</a> <span class="keywordtype">unsigned</span> <span class="keywordtype">char</span> <a class="code" href="filesys_8h.html#a8">OpenFile</a>(<span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> fileNumber){
00611   <span class="keywordtype">char</span> tempc;
00612 
00613   ConsoleWrite(<span class="stringliteral">"\rFilesystem: Looking for file "</span>);