fat_8h-source.html

avr应用测试程序

00133     CHAR    bsBootCode[448];            <span class="comment">// pad so structure is 512b</span>
00134     BYTE    bsBootSectSig0;             <span class="comment">// boot sector signature byte 0x55 </span>
00135     BYTE    bsBootSectSig1;             <span class="comment">// boot sector signature byte 0xAA</span>
00136 <span class="preprocessor">#define BOOTSIG0        0x55</span>
00137 <span class="preprocessor"></span><span class="preprocessor">#define BOOTSIG1        0xaa</span>
00138 <span class="preprocessor"></span>};
00139 
00140 <span class="keyword">struct </span>bootsector710 {
00141     BYTE    bsJump[3];                  <span class="comment">// jump inst E9xxxx or EBxx90</span>
00142     CHAR    bsOEMName[8];               <span class="comment">// OEM name and version</span>
00143     CHAR    bsBPB[53];                  <span class="comment">// BIOS parameter block</span>
00144     CHAR    bsExt[26];                  <span class="comment">// Bootsector Extension</span>
00145     CHAR    bsBootCode[418];            <span class="comment">// pad so structure is 512b</span>
00146     BYTE    bsBootSectSig2;             <span class="comment">// 2 &amp; 3 are only defined for FAT32?</span>
00147     BYTE    bsBootSectSig3;
00148     BYTE    bsBootSectSig0;             <span class="comment">// boot sector signature byte 0x55</span>
00149     BYTE    bsBootSectSig1;             <span class="comment">// boot sector signature byte 0xAA</span>
00150 <span class="preprocessor">#define BOOTSIG0        0x55</span>
00151 <span class="preprocessor"></span><span class="preprocessor">#define BOOTSIG1        0xaa</span>
00152 <span class="preprocessor"></span><span class="preprocessor">#define BOOTSIG2        0</span>
00153 <span class="preprocessor"></span><span class="preprocessor">#define BOOTSIG3        0</span>
00154 <span class="preprocessor"></span>};
00155 
00156 
00157 <span class="comment">/***************************************************************/</span>
00158 <span class="comment">/***************************************************************/</span>
00159 
00160 <span class="comment">// BIOS Parameter Block (BPB) for DOS 3.3</span>
00161 <span class="keyword">struct </span>bpb33 {
00162         WORD    bpbBytesPerSec; <span class="comment">// bytes per sector</span>
00163         BYTE    bpbSecPerClust; <span class="comment">// sectors per cluster</span>
00164         WORD    bpbResSectors;  <span class="comment">// number of reserved sectors</span>
00165         BYTE    bpbFATs;        <span class="comment">// number of FATs</span>
00166         WORD    bpbRootDirEnts; <span class="comment">// number of root directory entries</span>
00167         WORD    bpbSectors;     <span class="comment">// total number of sectors</span>
00168         BYTE    bpbMedia;       <span class="comment">// media descriptor</span>
00169         WORD    bpbFATsecs;     <span class="comment">// number of sectors per FAT</span>
00170         WORD    bpbSecPerTrack; <span class="comment">// sectors per track</span>
00171         WORD    bpbHeads;       <span class="comment">// number of heads</span>
00172         WORD    bpbHiddenSecs;  <span class="comment">// number of hidden sectors</span>
00173 };
00174 
00175 <span class="comment">// BPB for DOS 5.0</span>
00176 <span class="comment">// The difference is bpbHiddenSecs is a short for DOS 3.3,</span>
00177 <span class="comment">// and bpbHugeSectors is not present in the DOS 3.3 bpb.</span>
00178 <span class="keyword">struct </span>bpb50 {
00179         WORD    bpbBytesPerSec; <span class="comment">// bytes per sector</span>
00180         BYTE    bpbSecPerClust; <span class="comment">// sectors per cluster</span>
00181         WORD    bpbResSectors;  <span class="comment">// number of reserved sectors</span>
00182         BYTE    bpbFATs;        <span class="comment">// number of FATs</span>
00183         WORD    bpbRootDirEnts; <span class="comment">// number of root directory entries</span>
00184         WORD    bpbSectors;     <span class="comment">// total number of sectors</span>
00185         BYTE    bpbMedia;       <span class="comment">// media descriptor</span>
00186         WORD    bpbFATsecs;     <span class="comment">// number of sectors per FAT</span>
00187         WORD    bpbSecPerTrack; <span class="comment">// sectors per track</span>
00188         WORD    bpbHeads;       <span class="comment">// number of heads</span>
00189         DWORD   bpbHiddenSecs;  <span class="comment">// # of hidden sectors</span>
00190 <span class="comment">// 3.3 compat ends here</span>
00191         DWORD   bpbHugeSectors; <span class="comment">// # of sectors if bpbSectors == 0</span>
00192 };
00193 
00194 <span class="comment">// BPB for DOS 7.10 (FAT32)</span>
00195 <span class="comment">// This one has a few extensions to bpb50.</span>
00196 <span class="keyword">struct </span>bpb710 {
00197         WORD    bpbBytesPerSec; <span class="comment">// bytes per sector</span>
00198         BYTE    bpbSecPerClust; <span class="comment">// sectors per cluster</span>
00199         WORD    bpbResSectors;  <span class="comment">// number of reserved sectors</span>
00200         BYTE    bpbFATs;        <span class="comment">// number of FATs</span>
00201         WORD    bpbRootDirEnts; <span class="comment">// number of root directory entries</span>
00202         WORD    bpbSectors;     <span class="comment">// total number of sectors</span>
00203         BYTE    bpbMedia;       <span class="comment">// media descriptor</span>
00204         WORD    bpbFATsecs;     <span class="comment">// number of sectors per FAT</span>
00205         WORD    bpbSecPerTrack; <span class="comment">// sectors per track</span>
00206         WORD    bpbHeads;       <span class="comment">// number of heads</span>
00207         DWORD   bpbHiddenSecs;  <span class="comment">// # of hidden sectors</span>
00208 <span class="comment">// 3.3 compat ends here</span>
00209         DWORD   bpbHugeSectors; <span class="comment">// # of sectors if bpbSectors == 0</span>
00210 <span class="comment">// 5.0 compat ends here</span>
00211         DWORD     bpbBigFATsecs;<span class="comment">// like bpbFATsecs for FAT32</span>
00212         WORD      bpbExtFlags;  <span class="comment">// extended flags:</span>
00213 <span class="preprocessor">#define FATNUM    0xf           // mask for numbering active FAT</span>
00214 <span class="preprocessor"></span><span class="preprocessor">#define FATMIRROR 0x80          // FAT is mirrored (like it always was)</span>
00215 <span class="preprocessor"></span>        WORD      bpbFSVers;    <span class="comment">// filesystem version</span>
00216 <span class="preprocessor">#define FSVERS    0             // currently only 0 is understood</span>
00217 <span class="preprocessor"></span>        DWORD     bpbRootClust; <span class="comment">// start cluster for root directory</span>
00218         WORD      bpbFSInfo;    <span class="comment">// filesystem info structure sector</span>
00219         WORD      bpbBackup;    <span class="comment">// backup boot sector</span>
00220         <span class="comment">// There is a 12 byte filler here, but we ignore it</span>
00221 };
00222 
00223 
00224 
00225 
00226 <span class="comment">// ***************************************************************</span>
00227 <span class="comment">// * byte versions of the above structs                          *</span>
00228 <span class="comment">// ***************************************************************</span>
00229 
00230 
00231 <span class="comment">// BIOS Parameter Block (BPB) for DOS 3.3</span>
00232 <span class="keyword">struct </span>byte_bpb33 {
00233         CHAR bpbBytesPerSec[2];     <span class="comment">// bytes per sector</span>
00234         CHAR bpbSecPerClust;        <span class="comment">// sectors per cluster</span>
00235         CHAR bpbResSectors[2];      <span class="comment">// number of reserved sectors</span>
00236         CHAR bpbFATs;               <span class="comment">// number of FATs</span>
00237         CHAR bpbRootDirEnts[2];     <span class="comment">// number of root directory entries</span>
00238         CHAR bpbSectors[2];         <span class="comment">// total number of sectors</span>
00239         CHAR bpbMedia;              <span class="comment">// media descriptor</span>
00240         CHAR bpbFATsecs[2];         <span class="comment">// number of sectors per FAT</span>
00241         CHAR bpbSecPerTrack[2];     <span class="comment">// sectors per track</span>
00242         CHAR bpbHeads[2];           <span class="comment">// number of heads</span>
00243         CHAR bpbHiddenSecs[2];      <span class="comment">// number of hidden sectors</span>
00244 };
00245 
00246 <span class="comment">// BPB for DOS 5.0</span>
00247 <span class="comment">// The difference is bpbHiddenSecs is a short for DOS 3.3,</span>
00248 <span class="comment">// and bpbHugeSectors is not in the 3.3 bpb.</span>
00249 <span class="keyword">struct </span>byte_bpb50 {
00250         CHAR bpbBytesPerSec[2];     <span class="comment">// bytes per sector</span>
00251         CHAR bpbSecPerClust;        <span class="comment">// sectors per cluster</span>
00252         CHAR bpbResSectors[2];      <span class="comment">// number of reserved sectors</span>
00253         CHAR bpbFATs;               <span class="comment">// number of FATs</span>
00254         CHAR bpbRootDirEnts[2];     <span class="comment">// number of root directory entries</span>
00255         CHAR bpbSectors[2];         <span class="comment">// total number of sectors</span>
00256         CHAR bpbMedia;              <span class="comment">// media descriptor</span>
00257         CHAR bpbFATsecs[2];         <span class="comment">// number of sectors per FAT</span>
00258         CHAR bpbSecPerTrack[2];     <span class="comment">// sectors per track</span>
00259         CHAR bpbHeads[2];           <span class="comment">// number of heads</span>
00260         CHAR bpbHiddenSecs[4];      <span class="comment">// number of hidden sectors</span>
00261         CHAR bpbHugeSectors[4];     <span class="comment">// # of sectors if bpbSectors == 0</span>
00262 };
00263 
00264 <span class="comment">// BPB for DOS 7.10 (FAT32).</span>
00265 <span class="comment">// This one has a few extensions to bpb50.</span>
00266 <span class="keyword">struct </span>byte_bpb710 {
00267         BYTE bpbBytesPerSec[2];     <span class="comment">// bytes per sector</span>
00268         BYTE bpbSecPerClust;        <span class="comment">// sectors per cluster</span>
00269         BYTE bpbResSectors[2];      <span class="comment">// number of reserved sectors</span>
00270         BYTE bpbFATs;               <span class="comment">// number of FATs</span>
00271         BYTE bpbRootDirEnts[2];     <span class="comment">// number of root directory entries</span>