?? fat.c
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/*************************************************************/
/* FAT操作函數庫 */
/* 環境WinAVR 20060421 */
/* 作者：Bozai（章其波） */
/* E-mail：sudazqb@163.com */
/* 2007年2月13日 */
/*************************************************************/
/* 20071109: add & modify function for any directory music file playing */
/* 20071103: add function for lyric display */
/*History: 2007年2月13日 */
/* 添加了適合于RAM豐富的AVR單片機操作 的FAT表函數 */
/* 改進了查找FAT表的函數,使在硬盤操作時不需頻繁去讀FAT表. */
/* 注: 只適合RAM足夠多的單片機 */
/*************************************************************/
#include"FAT.h"
DWORD FirstDirClust; //first directory cluster
DWORD FirstDataSector; // The first sector number of data
WORD BytesPerSector; // Bytes per sector
DWORD FATsectors; // The amount sector a FAT occupied
WORD SectorsPerClust; // Sector per cluster
DWORD FirstFATSector; // The first FAT sector
DWORD FirstDirSector; // The first Dir sector
DWORD RootDirSectors; // The sector number a Root dir occupied
DWORD RootDirCount; // The count of directory in root dir
BYTE FAT32_Enable;
BYTE TABLE_READ = 0;
DWORD START_CLUSTER = 0x0ffffff8; //when the mcu has large ram
//BYTE FAT_TABLE[512]; //when the mcu has large ram
BYTE LongNameBuffer[MAX_LONG_NAME_SIZE];
BYTE LongNameFlag = 0;
BYTE (* FAT_ReadSector)(DWORD,BYTE *);
BYTE (* FAT_WriteSector)(DWORD,BYTE *);
DWORD (* FAT_ReadCapacity)(void);
//函數指針指向sd卡的讀寫函數
//BYTE (* FAT_ReadSector)(DWORD sector, BYTE * buffer) = CH375_ReadOneSector;
//BYTE (* FAT_WriteSector)(DWORD sector, BYTE * buffer) = CH375_WriteOneSector;
//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，用之前應先調用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;
BYTE buffer[512];
DWORD hidsec=0;
DWORD Capacity;
Capacity = FAT_ReadCapacity();
if(Capacity<0xff)return 1;
if(FAT_ReadSector(0,buffer))return 1;
bs = (struct bootsector710 *)buffer;
pr = (struct partrecord *)((struct partsector *)buffer)->psPart;//first partition
hidsec = pr->prStartLBA;//the hidden sectors
if(hidsec >= Capacity/512)
{
hidsec = 0;
}
else
{
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)
{
hidsec = 0;
if(FAT_ReadSector(0,buffer))return 1;//read the bpb sector
bs = (struct bootsector710 *)buffer;
}
}
if(bs->bsJump[0]!=0xE9 && bs->bsJump[0]!=0xEB)//對付沒有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占用的扇區數 //the sectors number occupied by one fat talbe
FirstDirClust = 2;
}
else
{
FAT32_Enable=1; //FAT32
FATsectors = bpb->bpbBigFATsecs;//FAT占用的扇區數 //the sectors number occupied by one fat talbe
FirstDirClust = bpb->bpbRootClust;
}
BytesPerSector = bpb->bpbBytesPerSec;//每扇區字節數
SectorsPerClust = (BYTE)bpb->bpbSecPerClust;//每簇扇區數
FirstFATSector = bpb->bpbResSectors+hidsec;//第一個FAT表扇區
RootDirCount = bpb->bpbRootDirEnts;//根目錄項數
RootDirSectors = (RootDirCount*32)>>9;//根目錄占用的扇區數
FirstDirSector = FirstFATSector+bpb->bpbFATs*FATsectors;//第一個目錄扇區
FirstDataSector = FirstDirSector+RootDirSectors;//第一個數據扇區
return 0;
}
//讀一個簇中的一個扇區
unsigned char FAT_LoadPartCluster(unsigned long cluster,unsigned part,BYTE * buffer)
{
DWORD sector;
sector=(DWORD)FirstDataSector+(DWORD)(cluster-2)*(DWORD)SectorsPerClust;//calculate the actual sector number
if(FAT_ReadSector(sector+part,buffer))return 1;
else return 0;
}
/*
//讀整個簇
//Read the a cluster
//Not suitable for system which has few data RAM
unsigned char FAT_LoadCluster(unsigned long cluster,BYTE * buffer)
{
DWORD sector;
unsigned char i;
sector=FirstDataSector+(DWORD)(cluster-2)*(DWORD)SectorsPerClust;//calculate the actual sector number
for(i=0;i<SectorsPerClust;i++)
{
if(FAT_ReadSector(sector+i,buffer+(i<<9)))break;
}
if(i==SectorsPerClust)return 0;
else return 1;
}*/
//讀下一簇簇號
//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
}
/*unsigned long FAT_NextCluster_NEW(unsigned long cluster)
{
//BYTE buffer[512];
BYTE temp;
DWORD sector;
DWORD offset;
if(cluster<2)return 0x0ffffff8;
if(FAT32_Enable)temp = 127;
else temp = 255;
offset = cluster/(temp+1);
sector=FirstFATSector+offset;//calculate the actual sector where the FAT placed
offset=cluster%(temp+1);//find the position //計算出在表中的偏移量
cluster -= offset;//找出需要的起始位置 ，以便于當前保存的起始簇號比較
if(TABLE_READ == 0 || cluster != START_CLUSTER)//從未讀過 or 不在已有的FAT表內 需重新讀
{
if(FAT_ReadSector(sector,FAT_TABLE))return 0x0ffffff8;//read fat table / return 0xfff8 when error occured
START_CLUSTER = cluster;
TABLE_READ = 1;
}
// if(cluster != START_CLUSTER)//不在已有的FAT表內 需重新讀
// {
// if(FAT_ReadSector(sector,FAT_TABLE))return 0x0ffffff8;//read fat table / return 0xfff8 when error occured
// START_CLUSTER = cluster;
// TABLE_READ = 1;
// }
if(FAT32_Enable)
{
// offset=cluster%128;//find the position
sector=((unsigned long *)FAT_TABLE)[offset];
}
else
{
// offset=cluster%256;//find the position
sector=((unsigned int *)FAT_TABLE)[offset];
}
return (unsigned long)sector;//return the cluste number
}*/
//在FAT表內找空簇
//Find a free cluster return the cluster number
unsigned long FAT_FindFreeCluster()
{
BYTE buffer[512];
//DWORD sector;
unsigned int i;
unsigned long cnt;
// sector=FirstFATSector+offset;//calculate the actual sector
//sector=FirstFATSector;
if(FAT32_Enable)
{
for(cnt=0;cnt<FATsectors;cnt++)//find in the FAT table
{
if(FAT_ReadSector(FirstFATSector+cnt,buffer))return 1;//error
for(i=0;i<128;i++)
{
if(((unsigned long *)buffer)[i]==0x00000000)break;//an unused cluster
}
if(i!=128)
{
cnt=cnt*128+i;
return cnt;//return the free cluster number
}
}
}
else
{
for(cnt=0;cnt<FATsectors;cnt++)//find in the FAT table
{
if(FAT_ReadSector(FirstFATSector+cnt,buffer))return 1;//error
for(i=0;i<256;i++)
{
if(((unsigned int *)buffer)[i]==0x0000)break;//an unused cluster
}
if(i!=256)
{
cnt=cnt*256+i;
return cnt;//return the free cluster number
}
}
}
return 1;//error
}
//在cluster指向的目錄下找一個空位置記錄文件
//find a position to place a item withe the given directory, the parameter is FileInfo who brought the message
unsigned int FAT_FindFreeItem(unsigned long cluster, struct FileInfoStruct *FileInfo)
{
BYTE *buffer;
DWORD tempclust;
DWORD sector;
unsigned int cnt;
unsigned int offset;
// unsigned char i;
struct direntry *item = 0;
if(cluster==0 && FAT32_Enable==0)// root directory//當這個目錄是根目錄
{
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;}//read sector
for(offset=0;offset<512;offset+=32)
{
item=(struct direntry *)(&buffer[offset]);
//used item
if(item->deName[0] == 0x00 || item->deName[0] == 0xe5)
//unused item
{
FileInfo->StartCluster = item->deStartCluster + (((unsigned long)item->deHighClust)<<16);//don't care
FileInfo->Size = item->deFileSize;//don't care
FileInfo->Attr = item->deAttributes;//don't care
FileInfo->Sector = FirstDirSector+cnt;//The key parameter record the secoter nuber which the item stored
FileInfo->Offset = offset; //The key parameter record the offset in the sector
free(buffer);//realease
return 0;//done
}
}
}
free(buffer);//release
}
else//other folders//當這是一個其它目錄時，程序暫且沒考慮到目錄內沒有空余項是需要另找一個簇來記錄
{
tempclust=cluster;
while(1)
{
sector=(unsigned long)FirstDataSector+(tempclust-2)*(unsigned long)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)
{
FileInfo->StartCluster = item->deStartCluster + (((unsigned long)item->deHighClust)<<16);
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( (FAT32_Enable == 0 && tempclust == 0xffff) || tempclust == 0x0ffffff8 || tempclust == 0x0fffffff)return 1;
}
}
return 1;
}
//顯示給定路徑下的文件
//display the content of a foler , 0 as root directory
unsigned char FAT_DisDir(BYTE *dir)
{
BYTE *buffer;
DWORD sector;
DWORD cluster;
DWORD tempclust;
unsigned int cnt;
unsigned int offset;
unsigned char i;
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))
{
USART_putchar(0x0d);
USART_putchar(0x0a);
for(i=0;i<8;i++)//name
{
USART_putchar(item->deName[i]);
}
if((item->deAttributes & 0x10)==0)USART_putchar('.');
for(i=0;i<3;i++)//extention
{
USART_putchar(item->deExtension[i]);
}
}
}
}
free(buffer);//release
}
else//other folders
{
tempclust=cluster;
while(1)
{
sector=(DWORD)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))
{
USART_putchar(0x0d);
USART_putchar(0x0a);
for(i=0;i<8;i++)
{
USART_putchar(item->deName[i]);
}
if((item->deAttributes & 0x10)==0)USART_putchar('.');
for(i=0;i<3;i++)
{
USART_putchar(item->deExtension[i]);
}
}
}
}
free(buffer);//release
tempclust=FAT_NextCluster(tempclust);//next cluster
if( tempclust == 0x0ffffff8 )return 1;
if((FAT32_Enable == 0 && tempclust == 0xffff) || tempclust == 0x0fffffff)break;
}
}
return 0;
}
//在給定目錄下查找文件
//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 int 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
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