📄 fat.c
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/*************************************************************/
/* MP3 FAT操作函数库 */
/* 环境WinAVR 20060421 */
/* 作者：Bozai（章其波） */
/* E-mail：sudazqb@163.com */
/* 2006年12月3日 */
/*************************************************************/
/* FAT diriver for MiniMP3 Player */
/* */
/* Platform : AVRStudio4.12 sp4 + WinAVR20060421 */
/* optimize -0s */
/* Author : bozai(Zhang Qibo) */
/* E-mail : sudazqb@163.com */
/* MSN : zhangqibo_1985@hotmail.com */
/* Date : 2006-12-29 */
/*******************************************************************/
#include"FAT.h"
DWORD FirstDirClust; //first directory cluster
DWORD FirstDataSector; // The first sector number of data
WORD BytesPerSector; // Bytes per sector
WORD FATsectors; // The amount sector a FAT occupied
WORD SectorsPerClust; // Sector per cluster
DWORD FirstFATSector; // The first FAT sector
DWORD FirstDirSector; // The first Dir sector
WORD RootDirSectors; // The sector number a Root dir occupied
WORD RootDirCount; // The count of directory in root dir
BYTE FAT32_Enable;
BYTE (* FAT_ReadSector)(DWORD,BYTE *);
BYTE (* FAT_WriteSector)(DWORD,BYTE *);
//函数指针指向sd卡的读写函数
//function pointer to the sd card read & write single block
//wirte sector are not use in this player
BYTE (* FAT_ReadSector)(DWORD sector, BYTE * buffer)=MMC_SD_ReadSingleBlock;//device read
BYTE (* FAT_WriteSector)(DWORD sector, BYTE * buffer)=MMC_SD_WriteSingleBlock;//device write
struct FileInfoStruct FileInfo;//temporarily buffer for file information
//FAT初始化，不含SD的初始化，用之前应先调用sd的初始化
unsigned char FAT_Init()//Initialize of FAT need initialize SD first
{
struct bootsector710 *bs = 0;
struct bpb710 *bpb = 0;
// struct partsector *ps = 0;
struct partrecord *pr = 0;
WORD hidsec=0;
BYTE buffer[512];
if(FAT_ReadSector(0,buffer))return 1;
bs = (struct bootsector710 *)buffer;
if(bs->bsJump[0]!=0xE9 && bs->bsJump[0]!=0xEB)
{
pr = (struct partrecord *)((struct partsector *)buffer)->psPart;//first partition
hidsec = pr->prStartLBA;//the hidden sectors
if(FAT_ReadSector(pr->prStartLBA,buffer))return 1;//read the bpb sector
bs = (struct bootsector710 *)buffer;
}
if(bs->bsJump[0]!=0xE9 && bs->bsJump[0]!=0xEB)//对付没有bootsect的sd卡 //dead with the card which has no bootsect
{
return 1;
}
bpb = (struct bpb710 *)bs->bsBPB;
if(bpb->bpbFATsecs)//detemine thd FAT type //do not support FAT12
{
FAT32_Enable=0; //FAT16
FATsectors = bpb->bpbFATsecs;//FAT占用的扇区数 //the sectors number occupied by one fat talbe
FirstDirClust = 2;
}
else
{
FAT32_Enable=1; //FAT32
FATsectors = bpb->bpbBigFATsecs;//FAT占用的扇区数 //the sectors number occupied by one fat talbe
FirstDirClust = bpb->bpbRootClust;
}
BytesPerSector = bpb->bpbBytesPerSec;//每扇区字节数
SectorsPerClust = (BYTE)bpb->bpbSecPerClust;//每簇扇区数
FirstFATSector = bpb->bpbResSectors+hidsec;//第一个FAT表扇区
RootDirCount = bpb->bpbRootDirEnts;//根目录项数
RootDirSectors = (RootDirCount*32)>>9;//根目录占用的扇区数
FirstDirSector = FirstFATSector+bpb->bpbFATs*FATsectors;//第一个目录扇区
FirstDataSector = FirstDirSector+RootDirSectors;//第一个数据扇区
return 0;
}
//读一个簇中的一个扇区
//read one sector of one cluster, parameter part indicate which sector
unsigned char FAT_LoadPartCluster(unsigned long cluster,unsigned part,BYTE * buffer)
{
DWORD sector;
sector=FirstDataSector+(DWORD)(cluster-2)*(DWORD)SectorsPerClust;//calculate the actual sector number
if(FAT_ReadSector(sector+part,buffer))return 1;
else return 0;
}
//读下一簇簇号
//Return the cluster number of next cluster of file
//Suitable for system which has limited RAM
unsigned long FAT_NextCluster(unsigned long cluster)
{
BYTE buffer[512];
DWORD sector;
DWORD offset;
if(FAT32_Enable)offset = cluster/128;
else offset = cluster/256;
if(cluster<2)return 0x0ffffff8;
sector=FirstFATSector+offset;//calculate the actual sector
if(FAT_ReadSector(sector,buffer))return 0x0ffffff8;//read fat table / return 0xfff8 when error occured
if(FAT32_Enable)
{
offset=cluster%128;//find the position
sector=((unsigned long *)buffer)[offset];
}
else
{
offset=cluster%256;//find the position
sector=((unsigned int *)buffer)[offset];
}
return (unsigned long)sector;//return the cluste number
}
//在给定目录下查找文件
//Find a item in the directory which specify by the parameter "cluster"
//Return the start cluster number
unsigned int FAT_FindItem(unsigned long cluster, BYTE *name, struct FileInfoStruct *FileInfo)
{
BYTE *buffer;
DWORD tempclust;
DWORD sector;
unsigned char cnt;
unsigned int offset;
unsigned char i;
struct direntry *item = 0;
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]);
if((item->deName[0] != 0x00) & (item->deName[0] != 0xe5) & (item->deAttributes != 0x0f))
{
for(i=0;i<11;i++)
{
if(buffer[offset+i]!=name[i])break;
}
if(i==11)
{
//return the parameter of the item
FileInfo->StartCluster = item->deStartCluster + (((unsigned long)item->deHighClust)<<16);//don't care
FileInfo->Size = item->deFileSize;
FileInfo->Attr = item->deAttributes;
FileInfo->Sector = FirstDirSector+cnt;
FileInfo->Offset = offset;
free(buffer);
return 0;
}
}
}
}
free(buffer);//release
}
else//other folders
{
tempclust=cluster;
while(1)
{
sector=FirstDataSector+(DWORD)(tempclust-2)*(DWORD)SectorsPerClust;//calculate the actual sector number
buffer=malloc(512);//apply memory
if(buffer==0)return 1;//if failed
for(cnt=0;cnt<SectorsPerClust;cnt++)
{
if(FAT_ReadSector(sector+cnt,buffer)){free(buffer);return 1;}
for(offset=0;offset<512;offset+=32)
{
item=(struct direntry *)(&buffer[offset]);
if((item->deName[0] != 0x00) & (item->deName[0] != 0xe5) & (item->deAttributes != 0x0f))
{
for(i=0;i<11;i++)
{
if(buffer[offset+i]!=name[i])break;
}
if(i==11)
{
FileInfo->StartCluster = item->deStartCluster + (((unsigned long)item->deHighClust)<<16);//don't care
FileInfo->Size = item->deFileSize;
FileInfo->Attr = item->deAttributes;
FileInfo->Sector = sector+cnt;
FileInfo->Offset = offset;
free(buffer);
return 0;
}
}
}
}
free(buffer);//release
tempclust=FAT_NextCluster(tempclust);//next cluster
if(tempclust == 0x0fffffff || tempclust == 0x0ffffff8 || (FAT32_Enable == 0 && tempclust == 0xffff))break;
}
}
return 1;
}
// 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;
}
//复制记录项信息 //copy item
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;
}
//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;
struct direntry *item = 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) & (item->deAttributes != 0x0f))
{
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 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 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;}
}
}
}
}
free(buffer);//release
}
else//other folders
{
tempclust=cluster;
while(1)
{
sector=FirstDataSector+(DWORD)(tempclust-2)*(DWORD)SectorsPerClust;//calculate the actual sector number
buffer=malloc(512);//apply memory
if(buffer==0)return 1;//if failed
for(cnt=0;cnt<SectorsPerClust;cnt++)
{
if(FAT_ReadSector(sector+cnt,buffer)){free(buffer);return 1;}
for(offset=0;offset<512;offset+=32)
{
item=(struct direntry *)(&buffer[offset]);
if((item->deName[0] != '.') & (item->deName[0] != 0x00) & (item->deName[0] != 0xe5) & (item->deAttributes != 0x0f))
{
if((item->deExtension[0] == 'M')&&(item->deExtension[1] == 'P')&&(item->deExtension[2] == '3'))
{
CopyDirentruyItem(MusicInfo,item);
i++;
if(i==*Count){free(buffer);return 0;}
}
else if((item->deExtension[0] == 'W')&&(item->deExtension[1] == 'M')&&(item->deExtension[2] == 'A'))
{
CopyDirentruyItem(MusicInfo,item);
i++;
if(i==*Count){free(buffer);return 0;}
}
else if((item->deExtension[0] == 'M')&&(item->deExtension[1] == 'I')&&(item->deExtension[2] == 'D'))
{
CopyDirentruyItem(MusicInfo,item);
i++;
if(i==*Count){free(buffer);return 0;}
}
else if((item->deExtension[0] == 'W')&&(item->deExtension[1] == 'A')&&(item->deExtension[2] == 'V'))
{
CopyDirentruyItem(MusicInfo,item);
i++;
if(i==*Count){free(buffer);return 0;}
}
}
}
}
free(buffer);//release
tempclust=FAT_NextCluster(tempclust);//next cluster
if(tempclust == 0x0fffffff || tempclust == 0x0ffffff8 || (FAT32_Enable == 0 && tempclust == 0xffff))break;
}
}
if(*Count==0)*Count=i;
return 0;
}
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