fat_8h-source.html

方便飞利浦arm7tdmi 处理器lpc2100开发的C函数库 Procyon ARMlib-LPC2100 C-Language Function Library for Philips LPC21

00129     CHAR    bsExt[26];                  <span class="comment">// Bootsector Extension</span>
00130     CHAR    bsBootCode[418];            <span class="comment">// pad so structure is 512b</span>
00131     BYTE    bsBootSectSig2;             <span class="comment">// 2 &amp; 3 are only defined for FAT32?</span>
00132     BYTE    bsBootSectSig3;
00133     BYTE    bsBootSectSig0;             <span class="comment">// boot sector signature byte 0x55</span>
00134     BYTE    bsBootSectSig1;             <span class="comment">// boot sector signature byte 0xAA</span>
00135 <span class="preprocessor">#define BOOTSIG0        0x55</span>
00136 <span class="preprocessor"></span><span class="preprocessor">#define BOOTSIG1        0xaa</span>
00137 <span class="preprocessor"></span><span class="preprocessor">#define BOOTSIG2        0</span>
00138 <span class="preprocessor"></span><span class="preprocessor">#define BOOTSIG3        0</span>
00139 <span class="preprocessor"></span>} GNUC_PACKED;
00140 
00141 
00142 <span class="comment">/***************************************************************/</span>
00143 <span class="comment">/***************************************************************/</span>
00144 
00145 <span class="comment">// BIOS Parameter Block (BPB) for DOS 3.3</span>
00146 <span class="keyword">struct </span>bpb33 {
00147         WORD    bpbBytesPerSec; <span class="comment">// bytes per sector</span>
00148         BYTE    bpbSecPerClust; <span class="comment">// sectors per cluster</span>
00149         WORD    bpbResSectors;  <span class="comment">// number of reserved sectors</span>
00150         BYTE    bpbFATs;        <span class="comment">// number of FATs</span>
00151         WORD    bpbRootDirEnts; <span class="comment">// number of root directory entries</span>
00152         WORD    bpbSectors;     <span class="comment">// total number of sectors</span>
00153         BYTE    bpbMedia;       <span class="comment">// media descriptor</span>
00154         WORD    bpbFATsecs;     <span class="comment">// number of sectors per FAT</span>
00155         WORD    bpbSecPerTrack; <span class="comment">// sectors per track</span>
00156         WORD    bpbHeads;       <span class="comment">// number of heads</span>
00157         WORD    bpbHiddenSecs;  <span class="comment">// number of hidden sectors</span>
00158 } GNUC_PACKED;
00159 
00160 <span class="comment">// BPB for DOS 5.0</span>
00161 <span class="comment">// The difference is bpbHiddenSecs is a short for DOS 3.3,</span>
00162 <span class="comment">// and bpbHugeSectors is not present in the DOS 3.3 bpb.</span>
00163 <span class="keyword">struct </span>bpb50 {
00164         WORD    bpbBytesPerSec; <span class="comment">// bytes per sector</span>
00165         BYTE    bpbSecPerClust; <span class="comment">// sectors per cluster</span>
00166         WORD    bpbResSectors;  <span class="comment">// number of reserved sectors</span>
00167         BYTE    bpbFATs;        <span class="comment">// number of FATs</span>
00168         WORD    bpbRootDirEnts; <span class="comment">// number of root directory entries</span>
00169         WORD    bpbSectors;     <span class="comment">// total number of sectors</span>
00170         BYTE    bpbMedia;       <span class="comment">// media descriptor</span>
00171         WORD    bpbFATsecs;     <span class="comment">// number of sectors per FAT</span>
00172         WORD    bpbSecPerTrack; <span class="comment">// sectors per track</span>
00173         WORD    bpbHeads;       <span class="comment">// number of heads</span>
00174         DWORD   bpbHiddenSecs;  <span class="comment">// # of hidden sectors</span>
00175 <span class="comment">// 3.3 compat ends here</span>
00176         DWORD   bpbHugeSectors; <span class="comment">// # of sectors if bpbSectors == 0</span>
00177 } GNUC_PACKED;
00178 
00179 <span class="comment">// BPB for DOS 7.10 (FAT32)</span>
00180 <span class="comment">// This one has a few extensions to bpb50.</span>
00181 <span class="keyword">struct </span>bpb710 {
00182         WORD    bpbBytesPerSec; <span class="comment">// bytes per sector</span>
00183         BYTE    bpbSecPerClust; <span class="comment">// sectors per cluster</span>
00184         WORD    bpbResSectors;  <span class="comment">// number of reserved sectors</span>
00185         BYTE    bpbFATs;        <span class="comment">// number of FATs</span>
00186         WORD    bpbRootDirEnts; <span class="comment">// number of root directory entries</span>
00187         WORD    bpbSectors;     <span class="comment">// total number of sectors</span>
00188         BYTE    bpbMedia;       <span class="comment">// media descriptor</span>
00189         WORD    bpbFATsecs;     <span class="comment">// number of sectors per FAT</span>
00190         WORD    bpbSecPerTrack; <span class="comment">// sectors per track</span>
00191         WORD    bpbHeads;       <span class="comment">// number of heads</span>
00192         DWORD   bpbHiddenSecs;  <span class="comment">// # of hidden sectors</span>
00193 <span class="comment">// 3.3 compat ends here</span>
00194         DWORD   bpbHugeSectors; <span class="comment">// # of sectors if bpbSectors == 0</span>
00195 <span class="comment">// 5.0 compat ends here</span>
00196         DWORD     bpbBigFATsecs;<span class="comment">// like bpbFATsecs for FAT32</span>
00197         WORD      bpbExtFlags;  <span class="comment">// extended flags:</span>
00198 <span class="preprocessor">#define FATNUM    0xf           // mask for numbering active FAT</span>
00199 <span class="preprocessor"></span><span class="preprocessor">#define FATMIRROR 0x80          // FAT is mirrored (like it always was)</span>
00200 <span class="preprocessor"></span>        WORD      bpbFSVers;    <span class="comment">// filesystem version</span>
00201 <span class="preprocessor">#define FSVERS    0             // currently only 0 is understood</span>
00202 <span class="preprocessor"></span>        DWORD     bpbRootClust; <span class="comment">// start cluster for root directory</span>
00203         WORD      bpbFSInfo;    <span class="comment">// filesystem info structure sector</span>
00204         WORD      bpbBackup;    <span class="comment">// backup boot sector</span>
00205         <span class="comment">// There is a 12 byte filler here, but we ignore it</span>
00206 } GNUC_PACKED;
00207 
00208 
00209 
00210 
00211 <span class="comment">// ***************************************************************</span>
00212 <span class="comment">// * byte versions of the above structs                          *</span>
00213 <span class="comment">// ***************************************************************</span>
00214 
00215 
00216 <span class="comment">// BIOS Parameter Block (BPB) for DOS 3.3</span>
00217 <span class="keyword">struct </span>byte_bpb33 {
00218         CHAR bpbBytesPerSec[2];     <span class="comment">// bytes per sector</span>
00219         CHAR bpbSecPerClust;        <span class="comment">// sectors per cluster</span>
00220         CHAR bpbResSectors[2];      <span class="comment">// number of reserved sectors</span>
00221         CHAR bpbFATs;               <span class="comment">// number of FATs</span>
00222         CHAR bpbRootDirEnts[2];     <span class="comment">// number of root directory entries</span>
00223         CHAR bpbSectors[2];         <span class="comment">// total number of sectors</span>
00224         CHAR bpbMedia;              <span class="comment">// media descriptor</span>
00225         CHAR bpbFATsecs[2];         <span class="comment">// number of sectors per FAT</span>
00226         CHAR bpbSecPerTrack[2];     <span class="comment">// sectors per track</span>
00227         CHAR bpbHeads[2];           <span class="comment">// number of heads</span>
00228         CHAR bpbHiddenSecs[2];      <span class="comment">// number of hidden sectors</span>
00229 } GNUC_PACKED;
00230 
00231 <span class="comment">// BPB for DOS 5.0</span>
00232 <span class="comment">// The difference is bpbHiddenSecs is a short for DOS 3.3,</span>
00233 <span class="comment">// and bpbHugeSectors is not in the 3.3 bpb.</span>
00234 <span class="keyword">struct </span>byte_bpb50 {
00235         CHAR bpbBytesPerSec[2];     <span class="comment">// bytes per sector</span>
00236         CHAR bpbSecPerClust;        <span class="comment">// sectors per cluster</span>
00237         CHAR bpbResSectors[2];      <span class="comment">// number of reserved sectors</span>
00238         CHAR bpbFATs;               <span class="comment">// number of FATs</span>
00239         CHAR bpbRootDirEnts[2];     <span class="comment">// number of root directory entries</span>
00240         CHAR bpbSectors[2];         <span class="comment">// total number of sectors</span>
00241         CHAR bpbMedia;              <span class="comment">// media descriptor</span>
00242         CHAR bpbFATsecs[2];         <span class="comment">// number of sectors per FAT</span>
00243         CHAR bpbSecPerTrack[2];     <span class="comment">// sectors per track</span>
00244         CHAR bpbHeads[2];           <span class="comment">// number of heads</span>
00245         CHAR bpbHiddenSecs[4];      <span class="comment">// number of hidden sectors</span>
00246         CHAR bpbHugeSectors[4];     <span class="comment">// # of sectors if bpbSectors == 0</span>
00247 } GNUC_PACKED;
00248 
00249 <span class="comment">// BPB for DOS 7.10 (FAT32).</span>
00250 <span class="comment">// This one has a few extensions to bpb50.</span>
00251 <span class="keyword">struct </span>byte_bpb710 {
00252         BYTE bpbBytesPerSec[2];     <span class="comment">// bytes per sector</span>
00253         BYTE bpbSecPerClust;        <span class="comment">// sectors per cluster</span>
00254         BYTE bpbResSectors[2];      <span class="comment">// number of reserved sectors</span>
00255         BYTE bpbFATs;               <span class="comment">// number of FATs</span>
00256         BYTE bpbRootDirEnts[2];     <span class="comment">// number of root directory entries</span>
00257         BYTE bpbSectors[2];         <span class="comment">// total number of sectors</span>
00258         BYTE bpbMedia;              <span class="comment">// media descriptor</span>
00259         BYTE bpbFATsecs[2];         <span class="comment">// number of sectors per FAT</span>
00260         BYTE bpbSecPerTrack[2];     <span class="comment">// sectors per track</span>
00261         BYTE bpbHeads[2];           <span class="comment">// number of heads</span>
00262         BYTE bpbHiddenSecs[4];      <span class="comment">// # of hidden sectors</span>
00263         BYTE bpbHugeSectors[4];     <span class="comment">// # of sectors if bpbSectors == 0</span>