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📄 fat.s

📁 mp3代码 要用的干净下啊 希望用东西共享啊
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12 
	.module fat.c
	.area text(rom, con, rel)
	.dbfile D:\桌面\mp3\FAT\fat.c
	.dbfunc e FAT_Init _FAT_Init fV
	.even
_FAT_Init::
	.dbline -1
	.dbline 23
; 
; 
; #include "config.h"
; 
; 
; uint8 FAT_ReadBlock(uint32 LBA);
; uint8 FAT_WriteBlock(uint32 LBA);
; uint8 IsEqual(void* A, void* B, uint8 Size);
; void ReadBPB(void);
; uint32 ClusConvLBA(uint16 ClusID);
; uint16 FAT_ReadFAT(uint16 Index);
; uint8 GetFileID(uint8 Name[11], DIR* ID);
; 
; 
; 
; static uint8    BUFFER[512];
; static FileSystemInfo  Info;
; static FATFileIndex     FileIndex;
; //******************************************************************************************** 
; //初始化驱动,建立必要数据结构 
; //void FAT_Init(void); 
; //******************************************************************************************** 
; void FAT_Init(void) {
	.dbline 24
;         ReadBPB();
	xcall _ReadBPB
	.dbline -2
L7:
	.dbline 0 ; func end
	ret
	.dbend
	.dbfunc e FAT_ReadBlock _FAT_ReadBlock fc
;            LBA -> y+2
	.even
_FAT_ReadBlock::
	xcall push_arg4
	sbiw R28,2
	.dbline -1
	.dbline 30
; }
; 
; //********************************************************************************************  
; //读一个扇区  
; //******************************************************************************************** 
; uint8 FAT_ReadBlock(uint32 LBA) {
	.dbline 31
;         return(MMC_Read_Sector(LBA , BUFFER));
	ldi R24,<_BUFFER
	ldi R25,>_BUFFER
	std y+1,R25
	std y+0,R24
	movw R30,R28
	ldd R16,z+2
	ldd R17,z+3
	ldd R18,z+4
	ldd R19,z+5
	xcall _MMC_Read_Sector
	.dbline -2
L8:
	adiw R28,6
	.dbline 0 ; func end
	ret
	.dbsym l LBA 2 l
	.dbend
	.dbfunc e FAT_WriteBlock _FAT_WriteBlock fc
;            LBA -> y+2
	.even
_FAT_WriteBlock::
	xcall push_arg4
	sbiw R28,2
	.dbline -1
	.dbline 38
; }
; //********************************************************************************************  
; //写一个扇区  
; //********************************************************************************************  
; 
; uint8 FAT_WriteBlock(uint32 LBA) 
; {
	.dbline 39
;         return(MMC_Write_Sector(LBA, BUFFER));
	ldi R24,<_BUFFER
	ldi R25,>_BUFFER
	std y+1,R25
	std y+0,R24
	movw R30,R28
	ldd R16,z+2
	ldd R17,z+3
	ldd R18,z+4
	ldd R19,z+5
	xcall _MMC_Write_Sector
	.dbline -2
L9:
	adiw R28,6
	.dbline 0 ; func end
	ret
	.dbsym l LBA 2 l
	.dbend
	.dbfunc e IsEqual _IsEqual fc
;              b -> R20,R21
;              a -> R22,R23
;              i -> R10
;           Size -> R12
;              B -> R18,R19
;              A -> R16,R17
	.even
_IsEqual::
	xcall push_gset4
	ldd R12,y+8
	.dbline -1
	.dbline 43
; }
; 
; uint8 IsEqual(void* A, void* B, uint8 Size) 
; {
	.dbline 44
;         uint8 i, *a = A, *b = B;
	movw R22,R16
	.dbline 44
	movw R20,R18
	.dbline 45
;         for(i = 0; i < Size; i++)
	clr R10
	xjmp L14
L11:
	.dbline 46
;                 if(*a++!= *b++)
	movw R30,R20
	ld R2,Z+
	movw R20,R30
	movw R30,R22
	ld R3,Z+
	movw R22,R30
	cp R3,R2
	breq L15
	.dbline 47
;                         return FALSE;
	clr R16
	xjmp L10
L15:
L12:
	.dbline 45
	inc R10
L14:
	.dbline 45
	cp R10,R12
	brlo L11
	.dbline 48
;         return TRUE;
	ldi R16,1
	.dbline -2
L10:
	xcall pop_gset4
	.dbline 0 ; func end
	ret
	.dbsym r b 20 pc
	.dbsym r a 22 pc
	.dbsym r i 10 c
	.dbsym r Size 12 c
	.dbsym r B 18 pV
	.dbsym r A 16 pV
	.dbend
	.dbfunc e ReadBPB _ReadBPB fV
	.dbstruct 0 512 .3
	.dbfield 0 BS_jmpBoot A[3:3]c
	.dbfield 3 BS_OEMName A[8:8]c
	.dbfield 11 BPB_BytesPerSec i
	.dbfield 13 BPB_SecPerClus c
	.dbfield 14 BPB_RsvdSecCnt i
	.dbfield 16 BPB_NumFATs c
	.dbfield 17 BPB_RootEntCnt i
	.dbfield 19 BPB_TotSec16 i
	.dbfield 21 BPB_Media c
	.dbfield 22 BPB_FATSz16 i
	.dbfield 24 BPB_SecPerTrk i
	.dbfield 26 BPB_NumHeads i
	.dbfield 28 BPB_HiddSec l
	.dbfield 32 BPB_TotSec32 l
	.dbfield 36 BS_DrvNum c
	.dbfield 37 BS_Reservedl c
	.dbfield 38 BS_BootSig c
	.dbfield 39 BS_VolID l
	.dbfield 43 BS_VolLab A[11:11]c
	.dbfield 54 BS_FilSysType A[8:8]c
	.dbfield 62 ExecutableCode A[448:448]c
	.dbfield 510 ExecutableMarker A[2:2]c
	.dbend
;            BPB -> R10,R11
	.even
_ReadBPB::
	xcall push_gset3
	.dbline -1
	.dbline 56
; }
; //********************************************************************************************  
; //读取BPB数据结构  
; //static void ReadBPB(void)  
; //********************************************************************************************  
; 
; void ReadBPB(void) 
; {
	.dbline 57
;         FAT_BPB* BPB = (FAT_BPB*)BUFFER;
	ldi R24,<_BUFFER
	ldi R25,>_BUFFER
	movw R10,R24
	.dbline 58
;         FAT_ReadBlock(0);
	ldi R16,0
	ldi R17,0
	ldi R18,0
	ldi R19,0
	xcall _FAT_ReadBlock
	.dbline 61
; 
;         //缓存相关参数
;         Info.BPB_SecPerClus     =   BPB->BPB_SecPerClus;
	movw R30,R10
	ldd R2,z+13
	sts _Info,R2
	.dbline 62
;         Info.BPB_RsvdSecCnt     =   BPB->BPB_RsvdSecCnt;
	movw R30,R10
	ldd R2,z+14
	ldd R3,z+15
	sts _Info+1+1,R3
	sts _Info+1,R2
	.dbline 63
;         Info.BPB_NumFATs        =   BPB->BPB_NumFATs;
	movw R30,R10
	ldd R2,z+16
	sts _Info+3,R2
	.dbline 64
;         Info.BPB_RootEntCnt     =   BPB->BPB_RootEntCnt;
	movw R30,R10
	ldd R2,z+17
	ldd R3,z+18
	sts _Info+4+1,R3
	sts _Info+4,R2
	.dbline 65
;         Info.BPB_TotSec16       =   BPB->BPB_TotSec16;
	movw R30,R10
	ldd R2,z+19
	ldd R3,z+20
	sts _Info+6+1,R3
	sts _Info+6,R2
	.dbline 66
;         Info.BPB_FATSz16        =   BPB->BPB_FATSz16;
	movw R30,R10
	ldd R2,z+22
	ldd R3,z+23
	sts _Info+8+1,R3
	sts _Info+8,R2
	.dbline 67
;         Info.BPB_HiddSec        =   BPB->BPB_HiddSec;
	movw R30,R10
	ldd R2,z+28
	ldd R3,z+29
	ldd R4,z+30
	ldd R5,z+31
	sts _Info+10+1,R3
	sts _Info+10,R2
	sts _Info+10+2+1,R5
	sts _Info+10+2,R4
	.dbline 69
; 
;     Info.DirStartSec        =   Info.BPB_RsvdSecCnt + Info.BPB_NumFATs * Info.BPB_FATSz16;  //获取根目录开始扇区号  
	lds R18,_Info+8
	lds R19,_Info+8+1
	lds R16,_Info+3
	clr R17
	xcall empy16s
	lds R2,_Info+1
	lds R3,_Info+1+1
	add R2,R16
	adc R3,R17
	clr R4
	clr R5
	sts _Info+14+1,R3
	sts _Info+14,R2
	sts _Info+14+2+1,R5
	sts _Info+14+2,R4
	.dbline 70
;     Info.DataStartSec       =   Info.DirStartSec + Info.BPB_RootEntCnt * 32 / 512;          //获取数据区开始扇区号  
	lds R18,_Info+4
	lds R19,_Info+4+1
	ldi R16,32
	ldi R17,0
	xcall empy16s
	ldi R18,9
	ldi R19,0
	xcall lsr16
	movw R2,R16
	clr R4
	clr R5
	lds R8,_Info+14+2
	lds R9,_Info+14+2+1
	lds R6,_Info+14
	lds R7,_Info+14+1
	add R6,R2
	adc R7,R3
	adc R8,R4
	adc R9,R5
	sts _Info+18+1,R7
	sts _Info+18,R6
	sts _Info+18+2+1,R9
	sts _Info+18+2,R8
	.dbline 71
;     Info.DirSecCount        =   Info.BPB_RootEntCnt * 32 / 512;    	   	 	  				//目录项占用的扇区数  
	lds R18,_Info+4
	lds R19,_Info+4+1
	ldi R16,32
	ldi R17,0
	xcall empy16s
	ldi R18,9
	ldi R19,0
	xcall lsr16
	sts _Info+22+1,R17
	sts _Info+22,R16
	.dbline -2
L17:
	xcall pop_gset3
	.dbline 0 ; func end
	ret
	.dbsym r BPB 10 pS[.3]
	.dbend
	.dbfunc e ClusConvLBA _ClusConvLBA fl
;         ClusID -> R10,R11
	.even
_ClusConvLBA::
	xcall push_gset3
	movw R10,R16
	.dbline -1
	.dbline 78
; }
; //********************************************************************************************  
; //获取一个簇的开始扇区  
; //********************************************************************************************  
; 
; uint32 ClusConvLBA(uint16 ClusID) 
; {
	.dbline 79
;         return Info.DataStartSec + Info.BPB_SecPerClus * (ClusID - 2);
	movw R18,R10
	subi R18,2
	sbci R19,0
	lds R16,_Info
	clr R17
	xcall empy16s
	movw R2,R16
	clr R4
	clr R5
	lds R8,_Info+18+2
	lds R9,_Info+18+2+1
	lds R6,_Info+18
	lds R7,_Info+18+1
	add R6,R2
	adc R7,R3
	adc R8,R4
	adc R9,R5
	movw R16,R6
	movw R18,R8
	.dbline -2
L33:
	xcall pop_gset3
	.dbline 0 ; func end
	ret
	.dbsym r ClusID 10 i
	.dbend
	.dbfunc e FAT_ReadFAT _FAT_ReadFAT fi
;            RAM -> R20,R21
;          Index -> R22,R23
	.even
_FAT_ReadFAT::
	xcall push_gset2
	movw R22,R16
	.dbline -1
	.dbline 85
; }
; //********************************************************************************************  
; //读取文件分配表的指定项  
; //********************************************************************************************  
; uint16 FAT_ReadFAT(uint16 Index) 
; {
	.dbline 86
;         uint16 *RAM = (uint16*)BUFFER;
	ldi R20,<_BUFFER
	ldi R21,>_BUFFER
	.dbline 87
;         FAT_ReadBlock(Info.BPB_RsvdSecCnt + Index / 256);
	movw R2,R22
	mov R2,R3
	clr R3
	lds R4,_Info+1
	lds R5,_Info+1+1
	add R4,R2
	adc R5,R3
	movw R2,R4
	clr R4
	clr R5
	movw R16,R2
	movw R18,R4
	xcall _FAT_ReadBlock
	.dbline 88
;         return RAM[Index % 256];
	movw R18,R22
	andi R19,0
	ldi R16,2
	ldi R17,0
	xcall empy16s
	movw R30,R16
	add R30,R20
	adc R31,R21
	ldd R16,z+0
	ldd R17,z+1
	.dbline -2
L35:
	xcall pop_gset2
	.dbline 0 ; func end
	ret
	.dbsym r RAM 20 pi
	.dbsym r Index 22 i
	.dbend
	.dbfunc e GetFileID _GetFileID fc
	.dbstruct 0 32 .4
	.dbfield 0 FileName A[11:11]c
	.dbfield 11 FileAttrib c
	.dbfield 12 UnUsed A[10:10]c
	.dbfield 22 FileUpdateTime A[2:2]c
	.dbfield 24 FileUpdateData A[2:2]c
	.dbfield 26 Start i
	.dbfield 28 Size l
	.dbend
;       DirStart -> R20,R21
;      DirSecCut -> R22,R23
;              i -> R10,R11
;              m -> R14,R15
;             ID -> R12,R13
;           Name -> y+11
	.even
_GetFileID::
	xcall push_arg4
	xcall push_gset5
	movw R12,R18
	sbiw R28,1
	.dbline -1
	.dbline 94
; }
; //********************************************************************************************  
; //获得和文件名对应的目录项  
; //********************************************************************************************  
; uint8 GetFileID(uint8 * Name, DIR* ID) 
; {
	.dbline 96
;         uint16 DirSecCut, DirStart, i, m;
;         DirSecCut = Info.DirSecCount;           //目录占扇区总数
	lds R22,_Info+22
	lds R23,_Info+22+1
	.dbline 97
;         DirStart = Info.DirStartSec;            //目录开始扇区
	lds R20,_Info+14
	lds R21,_Info+14+1
	.dbline 98
;         for(i = 0; i < DirSecCut; i++) 
	clr R10
	clr R11
	xjmp L43
L40:
	.dbline 99
; 		{
	.dbline 100
;                 if(!FAT_ReadBlock(DirStart + i))
	movw R2,R20
	add R2,R10
	adc R3,R11
	clr R4
	clr R5
	movw R16,R2
	movw R18,R4
	xcall _FAT_ReadBlock
	tst R16
	brne L44
	.dbline 101
; 				{
	.dbline 102
; 				        break;
	xjmp L42
L44:
	.dbline 104
; 				}
;                 for(m = 0; m <16; m++) 
	clr R14
	clr R15
	xjmp L49
L46:
	.dbline 105
; 				{
	.dbline 107
;                       //  if(IsEqual(Name, &((DIR*)&BUFFER[m * 32])->FileName, 11)) 
; 						if(IsEqual(Name, &BUFFER[m * 32], 11)) 
	ldi R24,11
	std y+0,R24
	ldi R16,32
	ldi R17,0
	movw R18,R14
	xcall empy16s
	movw R18,R16
	ldi R24,<_BUFFER
	ldi R25,>_BUFFER
	add R18,R24
	adc R19,R25
	ldd R16,y+11
	ldd R17,y+12
	xcall _IsEqual
	tst R16
	breq L50
	.dbline 108
; 						{
	.dbline 109
;                                 *ID = *((DIR*)&BUFFER[m * 32]);
	ldi R16,32
	ldi R17,0
	movw R18,R14
	xcall empy16s
	movw R2,R16
	ldi R24,<_BUFFER
	ldi R25,>_BUFFER
	add R2,R24
	adc R3,R25
	ldi R16,32
	ldi R17,0
	st -y,R13
	st -y,R12
	st -y,R3
	st -y,R2
	xcall asgnblk
	.dbline 110
;                                 return TRUE; 
	ldi R16,1
	xjmp L37
L50:
	.dbline 112
L47:
	.dbline 104
	movw R24,R14
	adiw R24,1
	movw R14,R24
L49:
	.dbline 104
	movw R24,R14
	cpi R24,16
	ldi R30,0
	cpc R25,R30
	brlo L46
	.dbline 113
L41:
	.dbline 98
	movw R24,R10
	adiw R24,1
	movw R10,R24
L43:
	.dbline 98
	cp R10,R22
	cpc R11,R23
	brsh X0
	xjmp L40
X0:
L42:
	.dbline 114
;                         }
;                 }
;         }
;         return FALSE;
	clr R16
	.dbline -2
L37:
	adiw R28,1
	xcall pop_gset5
	adiw R28,4
	.dbline 0 ; func end
	ret
	.dbsym r DirStart 20 i
	.dbsym r DirSecCut 22 i
	.dbsym r i 10 i
	.dbsym r m 14 i
	.dbsym r ID 12 pS[.4]
	.dbsym l Name 11 pc
	.dbend
	.dbfunc e FAT_FileOpen _FAT_FileOpen fl
;        FileDir -> y+0
;    BytePerClus -> R10,R11
;        ClusNum -> R12,R13
;          Start -> y+40
;           Name -> R12,R13
	.even
_FAT_FileOpen::
	st -y,r19
	st -y,r18
	xcall push_gset4
	movw R12,R16
	sbiw R28,32
	.dbline -1
	.dbline 120
; }
; //********************************************************************************************  
; //打开指定文件  
; //********************************************************************************************  
; uint32 FAT_FileOpen(uint8 * Name, uint32 Start) 
; {
	.dbline 123
;         uint16 BytePerClus, ClusNum;
;         DIR FileDir;
;         BytePerClus = Info.BPB_SecPerClus * 512; // 每簇的字节数
	lds R18,_Info
	clr R19
	ldi R16,512
	ldi R17,2
	xcall empy16s
	movw R10,R16
	.dbline 124
;         if (!GetFileID(Name, &FileDir))
	movw R18,R28
	movw R16,R12
	xcall _GetFileID
	tst R16
	brne L53
	.dbline 125
; 		    {
	.dbline 126
; 			return FALSE;
	ldi R16,0
	ldi R17,0
	ldi R18,0
	ldi R19,0
	xjmp L52
L53:
	.dbline 130
; 			}
; 
;         //计算开始位置所在簇的簇号
;         ClusNum = Start / BytePerClus;
	movw R2,R10
	clr R4
	clr R5
	movw R30,R28
	ldd R6,z+40
	ldd R7,z+41
	ldd R8,z+42
	ldd R9,z+43
	st -y,R5
	st -y,R4
	st -y,R3
	st -y,R2
	movw R16,R6
	movw R18,R8
	xcall div32u
	movw R12,R16
	.dbline 131
;         FileIndex.ClusID = FileDir.Start;
	ldd R2,y+26
	ldd R3,y+27
	sts _FileIndex+6+1,R3
	sts _FileIndex+6,R2
	.dbline 132
;         for(FileIndex.i = 0; FileIndex.i < ClusNum; FileIndex.i++)
	ldi R20,0
	ldi R21,0
	ldi R22,0
	ldi R23,0
12

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