fat.s

这个是通过51做的SD卡读写和MP3的程序！

	std z+10,R18
	std z+11,R19
	.dbline 215
; 						FirstDirSector = save;
	movw R30,R28
	ldd R2,z+4
	ldd R3,z+5
	ldd R4,z+6
	ldd R5,z+7
	sts _FirstDirSector+1,R3
	sts _FirstDirSector,R2
	sts _FirstDirSector+2+1,R5
	sts _FirstDirSector+2,R4
	.dbline 216
; 						baseentry = save2;
	sts _baseentry+1,R11
	sts _baseentry,R10
	.dbline 217
; 						if (rval)
	ldi R20,0
	ldi R21,0
	ldi R22,0
	ldi R23,0
	movw R30,R28
	ldd R2,z+8
	ldd R3,z+9
	ldd R4,z+10
	ldd R5,z+11
	cp R2,R20
	cpc R3,R21
	cpc R4,R22
	cpc R5,R23
	breq L69
	.dbline 218
; 							return rval;
	movw R30,R28
	ldd R16,z+8
	ldd R17,z+9
	ldd R18,z+10
	ldd R19,z+11
	xjmp L38
L69:
	.dbline 220
; 						else	
; 						{
	.dbline 222
; 							// reload original sector
; 							ReadBlock(sector-1);//ataReadSectors( DRIVE0,	sector-1, 1, SectorBuffer);
	ldi R20,1
	ldi R21,0
	ldi R22,0
	ldi R23,0
	movw R30,R28
	ldd R2,z+0
	ldd R3,z+1
	ldd R4,z+2
	ldd R5,z+3
	sub R2,R20
	sbc R3,R21
	sbc R4,R22
	sbc R5,R23
	movw R16,R2
	movw R18,R4
	xcall _ReadBlock
	.dbline 223
; 							entrycount--;			// decrement entry counter		
	lds R24,_entrycount
	lds R25,_entrycount+1
	sbiw R24,1
	sts _entrycount+1,R25
	sts _entrycount,R24
	.dbline 224
; 							*DirNameBuffer = 0;
	clr R2
	lds R30,_DirNameBuffer
	lds R31,_DirNameBuffer+1
	std z+0,R2
	.dbline 225
;                  	}
	.dbline 226
; 					}
	xjmp L67
L66:
	.dbline 228
; 					else // normal file entry
; 						if(entrycount == entry)		
	lds R2,_entrycount
	lds R3,_entrycount+1
	ldd R0,y+32
	ldd R1,y+33
	cp R2,R0
	cpc R3,R1
	brne L71
	.dbline 229
; 							break;
	xjmp L41
L71:
L67:
	.dbline 230
; 					hasBuffer = 0;	// clear buffer	
	clr R0
	clr R1
	std y+19,R1
	std y+18,R0
	.dbline 231
; 					entrycount++;	// increment entry counter		
	lds R24,_entrycount
	lds R25,_entrycount+1
	adiw R24,1
	sts _entrycount+1,R25
	sts _entrycount,R24
	.dbline 232
; 				}
L64:
	.dbline 234
; 				// else ignore short_name_only entries
; 			}
L47:
	.dbline 235
; 		}
L44:
	.dbline 236
; 		de++;
	ldd R24,y+14
	ldd R25,y+15
	adiw R24,32
	std y+15,R25
	std y+14,R24
	.dbline 237
; 		index++;
	ldd R24,y+16
	ldd R25,y+17
	adiw R24,1
	std y+17,R25
	std y+16,R24
	.dbline 238
L40:
	.dbline 238
; 	}	while (*de->deName || index == 16);	// 0 in de->deName[0] if no more entries
	ldd R30,y+14
	ldd R31,y+15
	ldd R2,z+0
	tst R2
	breq X12
	xjmp L39
X12:
	ldd R24,y+16
	ldd R25,y+17
	cpi R24,16
	ldi R30,0
	cpc R25,R30
	brne X13
	xjmp L39
X13:
L41:
	.dbline 240
; 
; 	if (hasBuffer == 0)		// end of entries
	ldd R0,y+18
	ldd R1,y+19
	tst R0
	brne L73
	tst R1
	brne L73
X5:
	.dbline 241
; 		return 0;
	ldi R16,0
	ldi R17,0
	ldi R18,0
	ldi R19,0
	xjmp L38
L73:
	.dbline 243
; 	
; 	FileSize = de->deFileSize;
	ldd R30,y+14
	ldd R31,y+15
	ldd R2,z+28
	ldd R3,z+29
	ldd R4,z+30
	ldd R5,z+31
	sts _FileSize+1,R3
	sts _FileSize,R2
	sts _FileSize+2+1,R5
	sts _FileSize+2,R4
	.dbline 244
; 	return (unsigned long) ((unsigned long)de->deHighClust << 16) + de->deStartCluster;
	ldd R30,y+14
	ldd R31,y+15
	ldd R2,z+26
	ldd R3,z+27
	clr R4
	clr R5
	ldd R30,y+14
	ldd R31,y+15
	ldd R6,z+20
	ldd R7,z+21
	clr R8
	clr R9
	movw R8,R6
	clr R6
	clr R7
	add R6,R2
	adc R7,R3
	adc R8,R4
	adc R9,R5
	movw R16,R6
	movw R18,R8
	.dbline -2
L38:
	adiw R28,22
	xcall pop_gset5
	adiw R28,2
	.dbline 0 ; func end
	ret
	.dbsym l rval 8 l
	.dbsym r save2 10 i
	.dbsym l save 4 l
	.dbsym l b 20 i
	.dbsym l sector 0 l
	.dbsym l hasBuffer 18 i
	.dbsym l index 16 I
	.dbsym l de 14 pS[direntry]
	.dbsym r p 12 pc
	.dbsym l we 12 pS[winentry]
	.dbsym r i 14 I
	.dbsym l entry 32 i
	.dbend
	.dbfunc e fatNextCluster _fatNextCluster fl
;         offset -> R10,R11
;         sector -> y+12
;      fatOffset -> y+8
;        fatMask -> y+4
;    nextCluster -> y+0
;        cluster -> y+22
	.even
_fatNextCluster::
	xcall push_arg4
	xcall push_gset3
	sbiw R28,16
	.dbline -1
	.dbline 251
; }
; 
; /*-----------------------------------------------------------------------
;  在FAT表中查询下一个簇所在扇区号
; -----------------------------------------------------------------------*/
; unsigned long fatNextCluster(unsigned long cluster)
; {
	.dbline 258
; 	unsigned long nextCluster;
; 	unsigned long fatMask;
; 	unsigned long fatOffset;
; 	unsigned long sector;
; 	unsigned int offset;
; 	
; 	if(Fat32Enabled)
	lds R2,_Fat32Enabled
	tst R2
	breq L76
	.dbline 259
; 	{
	.dbline 261
; 		// 一个表项为4bytes(32 bits)
; 		fatOffset = cluster << 2;
	ldi R24,2
	ldi R25,0
	movw R30,R28
	ldd R2,z+22
	ldd R3,z+23
	ldd R4,z+24
	ldd R5,z+25
	st -y,R24
	movw R16,R2
	movw R18,R4
	xcall lsl32
	movw R30,R28
	std z+8,R16
	std z+9,R17
	std z+10,R18
	std z+11,R19
	.dbline 263
; 		// 设置 FAT32 bit mask
; 		fatMask = FAT32_MASK;
	ldi R20,255
	ldi R21,255
	ldi R22,255
	ldi R23,15
	movw R30,R28
	std z+4,R20
	std z+5,R21
	std z+6,R22
	std z+7,R23
	.dbline 264
; 	}
	xjmp L77
L76:
	.dbline 266
; 	else
; 	{
	.dbline 268
; 		// 一个表项为2bytes(16 bits)
; 		fatOffset = cluster << 1;
	movw R30,R28
	ldd R2,z+22
	ldd R3,z+23
	ldd R4,z+24
	ldd R5,z+25
	lsl R2
	rol R3
	rol R4
	rol R5
	movw R30,R28
	std z+8,R2
	std z+9,R3
	std z+10,R4
	std z+11,R5
	.dbline 270
; 		// 设置 FAT16 bit mask
; 		fatMask = FAT16_MASK;
	ldi R20,255
	ldi R21,255
	ldi R22,0
	ldi R23,0
	movw R30,R28
	std z+4,R20
	std z+5,R21
	std z+6,R22
	std z+7,R23
	.dbline 271
; 	}
L77:
	.dbline 274
; 	
; 	//计算FAT扇区号
; 	sector = FirstFATSector + (fatOffset / BytesPerSector);
	lds R2,_BytesPerSector
	lds R3,_BytesPerSector+1
	clr R4
	clr R5
	movw R30,R28
	ldd R6,z+8
	ldd R7,z+9
	ldd R8,z+10
	ldd R9,z+11
	st -y,R5
	st -y,R4
	st -y,R3
	st -y,R2
	movw R16,R6
	movw R18,R8
	xcall div32u
	lds R4,_FirstFATSector+2
	lds R5,_FirstFATSector+2+1
	lds R2,_FirstFATSector
	lds R3,_FirstFATSector+1
	add R2,R16
	adc R3,R17
	adc R4,R18
	adc R5,R19
	movw R30,R28
	std z+12,R2
	std z+13,R3
	std z+14,R4
	std z+15,R5
	.dbline 276
; 	//计算FAT扇区号中表项的偏移地址
; 	offset = fatOffset % BytesPerSector;
	lds R2,_BytesPerSector
	lds R3,_BytesPerSector+1
	clr R4
	clr R5
	movw R30,R28
	ldd R6,z+8
	ldd R7,z+9
	ldd R8,z+10
	ldd R9,z+11
	st -y,R5
	st -y,R4
	st -y,R3
	st -y,R2
	movw R16,R6
	movw R18,R8
	xcall mod32u
	movw R10,R16
	.dbline 278
;     
; 	ReadBlock(sector);
	movw R30,R28
	ldd R16,z+12
	ldd R17,z+13
	ldd R18,z+14
	ldd R19,z+15
	xcall _ReadBlock
	.dbline 281
; 
; 	// 读取下一个簇号
; 	nextCluster = (*((unsigned long*) &((char*)BUFFER)[offset])) & fatMask;
	ldi R24,<_BUFFER
	ldi R25,>_BUFFER
	movw R30,R10
	add R30,R24
	adc R31,R25
	ldd R2,z+0
	ldd R3,z+1
	ldd R4,z+2
	ldd R5,z+3
	movw R30,R28
	ldd R6,z+4
	ldd R7,z+5
	ldd R8,z+6
	ldd R9,z+7
	and R2,R6
	and R3,R7
	and R4,R8
	and R5,R9
	movw R30,R28
	std z+0,R2
	std z+1,R3
	std z+2,R4
	std z+3,R5
	.dbline 284
; 
; 	// 是否文件的结束簇
; 	if (nextCluster == (CLUST_EOFE & fatMask))
	movw R30,R28
	ldd R2,z+4
	ldd R3,z+5
	ldd R4,z+6
	ldd R5,z+7
	movw R30,R28
	ldd R6,z+0
	ldd R7,z+1
	ldd R8,z+2
	ldd R9,z+3
	cp R6,R2
	cpc R7,R3
	cpc R8,R4
	cpc R9,R5
	brne L78
	.dbline 285
; 		nextCluster = 0;
	ldi R20,0
	ldi R21,0
	ldi R22,0
	ldi R23,0
	movw R30,R28
	std z+0,R20
	std z+1,R21
	std z+2,R22
	std z+3,R23
L78:
	.dbline 287
; 		
; 	return nextCluster;
	movw R30,R28
	ldd R16,z+0
	ldd R17,z+1
	ldd R18,z+2
	ldd R19,z+3
	.dbline -2
L75:
	adiw R28,16
	xcall pop_gset3
	adiw R28,4
	.dbline 0 ; func end
	ret
	.dbsym r offset 10 i
	.dbsym l sector 12 l
	.dbsym l fatOffset 8 l
	.dbsym l fatMask 4 l
	.dbsym l nextCluster 0 l
	.dbsym l cluster 22 l
	.dbend
	.area bss(ram, con, rel)
	.dbfile C:\DOCUME~1\pas\桌面\SD卡MP3程序\fat.c
_FileSize::
	.blkb 4
	.dbsym e FileSize _FileSize l
_FirstDirSector::
	.blkb 4
	.dbsym e FirstDirSector _FirstDirSector l
_FirstFATSector::
	.blkb 4
	.dbsym e FirstFATSector _FirstFATSector l
_SectorsPerCluster::
	.blkb 2
	.dbsym e SectorsPerCluster _SectorsPerCluster i
_BytesPerSector::
	.blkb 2
	.dbsym e BytesPerSector _BytesPerSector i
_FirstDataSector::
	.blkb 4
	.dbsym e FirstDataSector _FirstDataSector l
_Fat32Enabled::
	.blkb 1
	.dbsym e Fat32Enabled _Fat32Enabled c
_PartInfo::
	.blkb 16
	.dbstruct 0 16 partrecord
	.dbfield 0 prIsActive c
	.dbfield 1 prStartHead c
	.dbfield 2 prStartCylSect i
	.dbfield 4 prPartType c
	.dbfield 5 prEndHead c
	.dbfield 6 prEndCylSect i
	.dbfield 8 prStartLBA l
	.dbfield 12 prSize l
	.dbend
	.dbsym e PartInfo _PartInfo S[partrecord]
_DIRNAME_BUFFER_ADDR::
	.blkb 30
	.dbsym e DIRNAME_BUFFER_ADDR _DIRNAME_BUFFER_ADDR A[30:30]c
_LONGNAME_BUFFER_ADDR::
	.blkb 30
	.dbsym e LONGNAME_BUFFER_ADDR _LONGNAME_BUFFER_ADDR A[30:30]c
	.area data(ram, con, rel)
	.dbfile C:\DOCUME~1\pas\桌面\SD卡MP3程序\fat.c
L68:
	.blkb 2
	.area idata
	.byte 47,0
	.area data(ram, con, rel)
	.dbfile C:\DOCUME~1\pas\桌面\SD卡MP3程序\fat.c
L37:
	.blkb 5
	.area idata
	.byte 'R,'A,'T,'E,0
	.area data(ram, con, rel)
	.dbfile C:\DOCUME~1\pas\桌面\SD卡MP3程序\fat.c
L36:
	.blkb 2
	.area idata
	.byte 'M,0
	.area data(ram, con, rel)
	.dbfile C:\DOCUME~1\pas\桌面\SD卡MP3程序\fat.c
L33:
	.blkb 14
	.area idata
	.byte 'N,'o,32,'P,'a,'r,'t,'i,'t,'i,'o,'n,33,0
	.area data(ram, con, rel)
	.dbfile C:\DOCUME~1\pas\桌面\SD卡MP3程序\fat.c
L32:
	.blkb 6
	.area idata
	.byte 'F,'A,'T,51,50,0
	.area data(ram, con, rel)
	.dbfile C:\DOCUME~1\pas\桌面\SD卡MP3程序\fat.c
L30:
	.blkb 10
	.area idata
	.byte 'F,'A,'T,51,50,32,'L,'B,'A,0
	.area data(ram, con, rel)
	.dbfile C:\DOCUME~1\pas\桌面\SD卡MP3程序\fat.c
L28:
	.blkb 10
	.area idata
	.byte 'F,'A,'T,49,54,32,'L,'B,'A,0
	.area data(ram, con, rel)
	.dbfile C:\DOCUME~1\pas\桌面\SD卡MP3程序\fat.c
L26:
	.blkb 7
	.area idata
	.byte 'F,'A,'T,49,54,32,0
	.area data(ram, con, rel)
	.dbfile C:\DOCUME~1\pas\桌面\SD卡MP3程序\fat.c
L24:
	.blkb 10
	.area idata
	.byte 'D,'O,'S,'F,'A,'T,32,49,54,0
	.area data(ram, con, rel)
	.dbfile C:\DOCUME~1\pas\桌面\SD卡MP3程序\fat.c