fat.c

基于ATmega64单片机以及vs1003的SD卡方案的MP3播放源代码

	DWORD cluster=0;
	if(FAT32_Enable)cluster=FirstDirClust;
	if(*p != '\\')return 1;//invalid path
	while(*p)
	{
		if(*p == '\\')
		{
			deep++;
		}
		p++;
	}
	p=dir;
	for(i=0;i<deep-1;i++)
	{
		p++;
		for(j=0;j<11;j++)name[j]=0x20;
		j=0;
		while(*p != '\\')
		{
			if((*p) >= 'a' && (*p) <= 'z')name[j] = (*p++)-0x20;
			else name[j] = *p++;
			j++;
		}
		if(FAT_FindItem(cluster,name, &FileInfo))return 1;//find the directory
		cluster = FileInfo.StartCluster;
	}
	p++;
	for(j=0;j<11;j++)name[j]=0x20;
	j=0;
	while(*p != '.')//file must have a extention
	{
		if(*p>='a' && *p<='z')name[j]=(*p++)-0x20;
		else name[j]=*p++;
		j++;
	}
	j=8;
	p++;
	while(*p)
	{
		if(*p>='a' && *p<='z')name[j]=(*p++)-0x20;
		else name[j]=*p++;
		j++;
	}
	if(FAT_FindItem(cluster,name, &FileInfo))return 1;//find the file
	cluster = FileInfo.StartCluster;
	return cluster;
}

// find a directory with the given path
unsigned long FAT_OpenDir(BYTE * dir)
{
	BYTE name[11];
	BYTE *p=dir;
	BYTE deep=0;
	BYTE i,j;
	DWORD cluster=0;
	if(FAT32_Enable)cluster = FirstDirClust;
	if(*p != '\\')return 1;//invalid path
	while(*p)
	{
		if(*p == '\\')
		{
			deep++;
		}
		p++;
	}
	p=dir;
	for(i=0;i<deep-1;i++)
	{
		p++;
		for(j=0;j<11;j++)name[j]=0x20;
		j=0;
		while(*p != '\\')
		{
			if((*p) >= 'a' && (*p) <= 'z')name[j] = (*p++)-0x20;
			else name[j] = *p++;
			j++;
		}
		if(FAT_FindItem(cluster,name, &FileInfo))return 1;//find the directory
		cluster = FileInfo.StartCluster;
	}
	p++;
	for(j=0;j<11;j++)name[j]=0x20;
	j=0;
	while(*p)
	{
		if(*p>='a' && *p<='z')name[j]=(*p++)-0x20;
		else name[j]=*p++;
		j++;
	}
	if(j == 0)return cluster;
	if(FAT_FindItem(cluster,name, &FileInfo))return 1;//find the final directory
	cluster = FileInfo.StartCluster;
	return cluster;
}


unsigned int FAT_Close(unsigned long * p)
{
	*p=1;
	return 0;
}

// Output the data of a file
// size 0 means read all of the file
unsigned char FAT_Read(unsigned long pointer, unsigned long size)
{
	DWORD sector;
	DWORD tempclust=pointer;
	BYTE *buffer;
	unsigned int i=0,j=0;
	sector=(DWORD)FirstDataSector+(DWORD)(tempclust-2)*(DWORD)SectorsPerClust;
	if(size==0)size = FileInfo.Size;//whether need to read all
	USART_putchar(0x0d);
	USART_putchar(0x0a);//new line
	while(size)
	{
		buffer=malloc(512);
		if(FAT_ReadSector(sector+j,buffer)){free(buffer);return 1;}
		if(size<=512)
		{
			for(i=0;i<size;i++)
			{
				USART_putchar(buffer[i]);//output
			}
			free(buffer);
			return 0;//file over
		}
		else
		{
			for(i=0;i<512;i++)
			{
				USART_putchar(buffer[i]);
			}
			j++;
			if(j==SectorsPerClust)
			{
				j=0;
				free(buffer);
				tempclust=FAT_NextCluster(tempclust);//find the next cluster the data was stored
				if((FAT32_Enable == 0 && tempclust == 0xffff) || tempclust == 0x0ffffff8 || tempclust == 0x0fffffff)return 1;//error
				sector=(DWORD)FirstDataSector+(DWORD)(tempclust-2)*(DWORD)SectorsPerClust;//reculculate the sector
			}
			else free(buffer);
			size-=512;
			
		}
	}
	return 0;
}

// write data to a file
unsigned char FAT_Write(unsigned long cluster,unsigned char *data,unsigned long size)
{
	BYTE buffer[512];
	DWORD sector;
	unsigned int i;
	for(i=0;i<size;i++)
	{
		buffer[i]=data[i];
	}
	sector=(DWORD)FirstDataSector+(DWORD)(cluster-2)*(DWORD)SectorsPerClust;
	if(FAT_WriteSector(sector,buffer))return 1;//write the data
	return 0;
}

//Delete a file
unsigned char FAT_Delete(BYTE *dir)
{
//	BYTE *buffer;
//	struct direntry *item;
//	WORD cluster;
	if(FAT_Open(dir)==0)return 1;//open the file
	if(FAT_DelItem(&FileInfo))return 1;//delete it
	return 0;
}

//Delete an item
unsigned char FAT_DelItem(struct FileInfoStruct *FileInfo)
{
	BYTE *buffer;
	struct direntry *item;
	DWORD cluster;
	DWORD tempclust;
	buffer=malloc(512);
	if(buffer==0)return 1;
	if(FAT_ReadSector(FileInfo->Sector,buffer)){free(buffer);return 1;}
	item=(struct direntry *)(&buffer[FileInfo->Offset]);
	item->deName[0]=0xe5;//mark it was deleted
	if(FAT_WriteSector(FileInfo->Sector,buffer)){free(buffer);return 1;}
	free(buffer);
	cluster=FileInfo->StartCluster;
	if(FileInfo->Attr & 0x10)//if the item is a folder
	{
		while(1)
		{
			while(FAT_SelectOneItem(cluster,FileInfo)==0)
			{
				if(FAT_DelItem(FileInfo))return 1;//nest for deleting folder
			}
			tempclust=FAT_NextCluster(cluster);//if the folder contain many item
			if(tempclust==1)return 1;
			if(FAT_ModifyFAT(cluster,0))return 1;//release the fat table
			cluster=tempclust;
			if(cluster == 0x0ffffff8)return 1;//error
			if((FAT32_Enable == 0 && tempclust == 0xffff) || tempclust == 0x0fffffff)break;//the end of the directory
		}
	}
	else// the item is a file
	{ 
		while(1)
		{
			tempclust=FAT_NextCluster(cluster);//save the next cluster
			if(tempclust==1)return 1;
			if(FAT_ModifyFAT(cluster,0))return 1;//delete curent cluster
			cluster=tempclust;
			//tempclust=FAT_NextCluster(cluster);
			if(cluster == 0x0ffffff8)return 1;//error
			if((FAT32_Enable == 0 && tempclust == 0xffff) || tempclust == 0x0fffffff)break;//the end of the file
		}
		//if(FAT_ModifyFAT(cluster,0))return 1;//delete the final cluster
	}
	return 0;	//done
}

//Rename a directory or a file
unsigned char FAT_Rename(BYTE *dir,BYTE *newname)
{
	BYTE name[11];
	BYTE *p=dir;
	BYTE deep=0;
	BYTE i,j;
//	BYTE directory=0;
	DWORD cluster=0;
	BYTE *buffer;
	struct direntry *item;
	if(FAT32_Enable)cluster=FirstDirClust;
	if(*p != '\\')return 1;//invalid path
	while(*p)
	{
		if(*p == '\\')
		{
			deep++;
		}
		p++;
	}
	p=dir;
	for(i=0;i<deep-1;i++)
	{
		p++;
		for(j=0;j<11;j++)name[j]=0x20;
		j=0;
		while(*p != '\\')
		{
			if((*p) >= 'a' && (*p) <= 'z')name[j] = (*p++)-0x20;
			else name[j] = *p++;
			j++;
		}
		if(FAT_FindItem(cluster,name, &FileInfo))return 1;
		cluster = FileInfo.StartCluster;
	}
	p++;
	for(j=0;j<11;j++)name[j]=0x20;
	j=0;
	while((*p != '.') && (*p) )//compatalbe for folder and file
	{
		if(*p>='a' && *p<='z')name[j]=(*p++)-0x20;
		else name[j]=*p++;
		j++;
	}
	j=8;
	if(*p == '.')//if it is a file
	{
		p++;
		while(*p)
		{
			if(*p>='a' && *p<='z')name[j]=(*p++)-0x20;
			else name[j]=*p++;
			j++;
		}
	}
	//else ;//It is a directory 
	if(FAT_FindItem(cluster,name, &FileInfo))return 1;//get the file or directory information
	buffer=malloc(512);
	if(buffer==0)return 1;
	if(FAT_ReadSector(FileInfo.Sector,buffer)){free(buffer);return 1;}//read the item according the information
	item=(struct direntry *)(&buffer[FileInfo.Offset]);

	//modify the name

	p=newname;
	for(j=0;j<11;j++)item->deName[j]=0x20;
	j=0;
	while((*p != '.') && (*p))
	{
		if(*p>='a' && *p<='z')item->deName[j]=(*p++)-0x20;
		else item->deName[j]=*p++;
		j++;
	}
	j=8;
	if(*p == '.')//if it is a file
	{
		p++;
		while(*p)
		{
			if(*p>='a' && *p<='z')item->deName[j]=(*p++)-0x20;
			else item->deName[j]=*p++;
			j++;
		}
	}
	if(FAT_WriteSector(FileInfo.Sector,buffer)){free(buffer);return 1;}//rewrite the item
	free(buffer);
	return 0;//done	
}



//复制记录项信息
void CopyDirentruyItem(struct direntry *Desti,struct direntry *Source)
{
	BYTE i;
	for(i=0;i<8;i++)Desti->deName[i] = Source->deName[i];
	for(i=0;i<3;i++)Desti->deExtension[i] = Source->deExtension[i];
	Desti->deAttributes = Source->deAttributes;
	Desti->deLowerCase = Source->deLowerCase;
	Desti->deCHundredth = Source->deCHundredth;
	for(i=0;i<2;i++)Desti->deCTime[i] = Source->deCTime[i];
	for(i=0;i<2;i++)Desti->deCDate[i] = Source->deCDate[i];
	for(i=0;i<2;i++)Desti->deADate[i] = Source->deADate[i];
	Desti->deHighClust = Source->deHighClust;
	for(i=0;i<2;i++)Desti->deMTime[i] = Source->deMTime[i];
	for(i=0;i<2;i++)Desti->deMDate[i] = Source->deMDate[i];
	Desti->deStartCluster = Source->deStartCluster;
	Desti->deFileSize = Source->deFileSize;
}

#if FIX_DIRECTORY

//search the file , when *count = 0 it will bring the number whole songs, when *cout != 0 the *MusicInfo will bring the infomation of the file
BYTE Search(BYTE *dir,struct direntry *MusicInfo,WORD *Count,BYTE *type)//当COUNT为零时，有它带回这个目录下总共有多少首音乐
{                                                            //不为零时有MusicInfo带回第Count首歌的详细文件信息
	BYTE *buffer;
	//BYTE buff[3];
	DWORD sector;
	DWORD cluster;
	DWORD tempclust;
	unsigned char cnt;
	unsigned int offset;
	unsigned int i=0;
	unsigned char j;//long name buffer offset;
	unsigned char *p;//long name buffer pointer
	struct direntry *item = 0;
	struct winentry *we =0;
	cluster = FAT_OpenDir(dir);
	if(cluster == 1)return 1;
	if(cluster==0 && FAT32_Enable==0)// root directory
	{
		buffer=malloc(512);//apply memory
		if(buffer==0)return 1;//if failed
		for(cnt=0;cnt<RootDirSectors;cnt++)
		{
			if(FAT_ReadSector(FirstDirSector+cnt,buffer)){free(buffer);return 1;}
			for(offset=0;offset<512;offset+=32)
			{
				item=(struct direntry *)(&buffer[offset]);//pointer convert
				//find a valid item and display it
				if((item->deName[0] != '.') && (item->deName[0] != 0x00) && (item->deName[0] != 0xe5))
				{
					if(item->deAttributes == 0x0f)
					{
						we = (struct winentry *)(&buffer[offset]);
						j = 26 *( (we->weCnt-1) & WIN_CNT);
                        			if(j<MAX_LONG_NAME_SIZE-25)
						{
							p = &LongNameBuffer[j];
							for (j=0;j<10;j++)	*p++ = we->wePart1[j];			
							for (j=0;j<12;j++)	*p++ = we->wePart2[j];
							for (j=0;j<4;j++)	*p++ = we->wePart3[j];	
							if (we->weCnt & 0x40) (*(unsigned int *)p) = 0;				
							if ((we->weCnt & WIN_CNT) == 1) LongNameFlag = 1;	
						}
						LongNameBuffer[MAX_LONG_NAME_SIZE-1] = 0;
						LongNameBuffer[MAX_LONG_NAME_SIZE-2] = 0;
						/*p = &LongNameBuffer[j];
						for (j=0;j<10;j++)	*p++ = we->wePart1[j];			
						for (j=0;j<12;j++)	*p++ = we->wePart2[j];
						for (j=0;j<4;j++)	*p++ = we->wePart3[j];	
						if (we->weCnt & 0x40) (*(unsigned int *)p) = 0;				
						if ((we->weCnt & WIN_CNT) == 1) LongNameFlag = 1;	*/
					}
					else if((item->deExtension[0] == 'M')&&(item->deExtension[1] == 'P')&&(item->deExtension[2] == '3'))
					{
						CopyDirentruyItem(MusicInfo,item);
						*type=1;
						i++;
						if(i==*Count){free(buffer);return 0;}
						else LongNameFlag = 0;	
					}
					else if((item->deExtension[0] == 'W')&&(item->deExtension[1] == 'M')&&(item->deExtension[2] == 'A'))
					{
						CopyDirentruyItem(MusicInfo,item);
						*type=2;
						i++;
						if(i==*Count){free(buffer);return 0;}
						else LongNameFlag = 0;	
					}
					else if((item->deExtension[0] == 'M')&&(item->deExtension[1] == 'I')&&(item->deExtension[2] == 'D'))
					{
						CopyDirentruyItem(MusicInfo,item);
						*type=3;
						i++;
						if(i==*Count){free(buffer);return 0;}
						else LongNameFlag = 0;	
					}
					else if((item->deExtension[0] == 'W')&&(item->deExtension[1] == 'A')&&(item->deExtension[2] == 'V'))
					{
						CopyDirentruyItem(MusicInfo,item);
						*type=4;
						i++;
						if(i==*Count){free(buffer);return 0;}
						else LongNameFlag = 0;	
					}
					else LongNameFlag = 0;
				}
			}
		}
		free(buffer);//release
	}