?? filesystem.c
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* Return :DWORD amount of files and directories
*******************************************************************/
DWORD fnDetectDirectory(DWORD startcluster)
{
BYTE item;
WORD recordoffset;
DWORD x=0;
BYTE stringnum=0;
DWORD filenum=0;
currentcluster_t current_cluster;
current_cluster.value=startcluster;
current_cluster.offset=0;
while (current_cluster.value!= 0xFFFFFFFF) // Do while not end of cluster chain
{
// Read Sector
current_cluster = fnFAT32_SectorReader(current_cluster, x++);
if (current_cluster.value!=0xFFFFFFFF)
{
for (item=0; item<=15;item++)
{
recordoffset = (32*item);
if ( fnFATMisc_If_LFN_Exists(recordoffset,stringnum) )
{
filenum++; //File / Dir Count
}
else if ( fnFATMisc_If_noLFN_SFN_Only(recordoffset) )
{
filenum++; //File / Dir Count
}
}// end of for
}
}
return filenum;
}
/******************************************************************
* Function : fnListDirectory
* Description : open a directory, get all file pointers of all files in the directory and store them in FILELIST_t.
* Input :
* DWORD startcluster-starting sector of curret directory
* Return :FILELIST_t file list pointer
*******************************************************************/
FILELIST_t* fnListDirectory(DWORD startcluster)
{
BYTE i,item,index;
WORD recordoffset;
BYTE LFNIndex=0;
DWORD x=0;
currentcluster_t current_cluster;
BYTE stringnum=0,next_num=0;
BYTE chksum;
DWORD filenumber=0;
BYTE String_buffer[20*13];
BYTE short_name[11];
WORD name_size=0;
current_cluster.value=startcluster;
current_cluster.offset=0;
FILELIST_t *filelist=NULL;
//get numbers of files in current directory
filenumber = fnDetectDirectory(startcluster);
filelist=(FILELIST_t *)malloc(sizeof(FILELIST_t));
filelist->list=(FILE_t **)malloc(sizeof(FILE_t *)*(filenumber));
filelist->num=filenumber;
if(filenumber==0)
{
return NULL;
}
filenumber=0;
while (current_cluster.value!= 0xFFFFFFFF) // Do while not end of cluster chain
{
// Read Sector
current_cluster = fnFAT32_SectorReader(current_cluster, x++);
if (current_cluster.value!=0xFFFFFFFF)
{
LFNIndex=0;
for (item=0; item<=15;item++)
{
recordoffset = (32*item);
//check entry type
if ( fnFATMisc_If_LFN_Invalid(recordoffset) )
{
//invalid entry
stringnum = 0;
name_size = 0;
next_num =0 ;
continue;
}
// Long File Name Text Found
else if ( fnFATMisc_If_LFN_TextOnly(recordoffset) )
{
// if file name entry
if(stringnum==0)
{
//check last entry by checking bit-7, first byte in file name entry
if((fnIDE_SectorByte(recordoffset)&0x40)!=0)
{
LFNIndex =fnIDE_SectorByte(recordoffset)&0x1F;
stringnum = LFNIndex;
next_num = stringnum;
chksum = fnIDE_SectorByte(recordoffset+0x0D);
}
else
{
// do nothing if bit-7 is not '1'.
continue;
}
}
else
{
// check file name serial number and check code, correct-get file name charaters, error-reset with 0
if(((fnIDE_SectorByte(recordoffset)&0x1F)==next_num)&&(fnIDE_SectorByte(recordoffset+0x0D)==chksum))
{
LFNIndex =(fnIDE_SectorByte(recordoffset)&0x1F);
}
else
{
stringnum = 0;
name_size = 0;
next_num =0 ;
continue;
}
}
name_size += fnFATMisc_cacheLFN(recordoffset,LFNIndex,String_buffer);
next_num--;
}
// Normal Entry and Long text exists
else if ( fnFATMisc_If_LFN_Exists(recordoffset,stringnum) )
{
filelist->list[filenumber]=(FILE_t*)malloc(sizeof(FILE_t));
fnIDE_SectorData(recordoffset,short_name,11);
// check file name serial number and check code, correct-get long file name charaters, error-get short file name
if((next_num!=0)||(chksum!=fnGetChksum(short_name)))
fnFindFile_ShortName(x-1,item,startcluster,filelist->list[filenumber]);
else
fnFindFile_LongName(x-1,item,startcluster,String_buffer,name_size,filelist->list[filenumber]);
filenumber++;
stringnum = 0;
name_size = 0;
next_num =0 ;
}
// Normal Entry, only 8.3 Text
else if ( fnFATMisc_If_noLFN_SFN_Only(recordoffset) )
{
filelist->list[filenumber]=(FILE_t*)malloc(sizeof(FILE_t));
fnFindFile_ShortName(x-1,item,startcluster,filelist->list[filenumber]);
filenumber++;
stringnum = 0;
name_size = 0;
next_num =0 ;
}
}// end of for
}
}
return filelist;
}
/******************************************************************
* Function : fnFindFile
* Description : search a file or directory.
* Input :
* DWORD startcluster-starting sector of curret directory
* BYTE* filename-target file name
* BYTE mode -file type: file or directory
* Return :FILE_t - file pointer if found, or none
*******************************************************************/
FILE_t *fnFindFile(DWORD startcluster,BYTE *filename,BYTE mode)
{
BYTE i,item,index;
WORD recordoffset;
BYTE LFNIndex=0;
DWORD x=0;
currentcluster_t current_cluster;
BYTE stringnum=0,next_num=0;
BYTE chksum;
DWORD filenumber=0;
BYTE String_buffer[20*13];
BYTE short_name[11];
WORD name_size=0;
FILE_t *fp;
current_cluster.value = startcluster;
current_cluster.offset = 0;
fp = (FILE_t*)malloc(sizeof(FILE_t));
fp->flag=0;
//
while (current_cluster.value!= 0xFFFFFFFF) // Do while not end of cluster chain
{
// Read Sector
current_cluster = fnFAT32_SectorReader(current_cluster, x++);
if (current_cluster.value!=0xFFFFFFFF)
{
LFNIndex=0;
for (item=0; item<=15;item++)
{
recordoffset = (32*item);
//check entry type
if ( fnFATMisc_If_LFN_Invalid(recordoffset) )
{
// check file name, reset with 0 if invalid
stringnum = 0;
name_size = 0;
next_num =0 ;
continue;
}
// Long File Name Text Found
else if ( fnFATMisc_If_LFN_TextOnly(recordoffset) )
{
//if long file name entry
if(stringnum==0)
{
//check last entry by checking bit-7, first byte in file name entry
if((fnIDE_SectorByte(recordoffset)&0x40)!=0)
{
LFNIndex =fnIDE_SectorByte(recordoffset)&0x1F;
stringnum = LFNIndex;
next_num = stringnum;
chksum = fnIDE_SectorByte(recordoffset+0x0D);
}
else
{
continue;
}
}
else
{
if(((fnIDE_SectorByte(recordoffset)&0x1F)==next_num)&&(fnIDE_SectorByte(recordoffset+0x0D)==chksum))
{
LFNIndex =(fnIDE_SectorByte(recordoffset)&0x1F);
}
else
{
stringnum = 0;
name_size = 0;
next_num =0 ;
continue;
}
}
name_size += fnFATMisc_cacheLFN(recordoffset,LFNIndex,String_buffer);
next_num--;
}
// Normal Entry and Long text exists
else if ( fnFATMisc_If_LFN_Exists(recordoffset,stringnum) )
{
//check search mode and entry type matched or not.
if(((fnIDE_SectorByte(recordoffset+0x0B)&FILE_ATTR_DIRECTORY)==0&&mode==FIND_FILE_MODE)||
((fnIDE_SectorByte(recordoffset+0x0B)&FILE_ATTR_DIRECTORY)!=0&&mode==FIND_DIR_MODE)||
(mode==FIND_ALL_MODE))
{
fnIDE_SectorData(recordoffset,short_name,11);
if((next_num!=0)||(chksum!=fnGetChksum(short_name)))
fnFindFile_ShortName(x-1,item,startcluster,fp);
else
fnFindFile_LongName(x-1,item,startcluster,String_buffer,name_size,fp);
filenumber++;
stringnum = 0;
name_size = 0;
next_num =0 ;
i=0;
while(1)
{
if(__tolower(filename[i])!=__tolower(fp->filename[i]))
{
break;
}
if(filename[i]=='\0')
{
return fp;
}
i++;
}
}
}
// Normal Entry, only 8.3 Text
else if ( fnFATMisc_If_noLFN_SFN_Only(recordoffset) )
{
if(((fnIDE_SectorByte(recordoffset+0x0B)&FILE_ATTR_DIRECTORY)==0&&mode==FIND_FILE_MODE)||
((fnIDE_SectorByte(recordoffset+0x0B)&FILE_ATTR_DIRECTORY)!=0&&mode==FIND_DIR_MODE)||
(mode==FIND_ALL_MODE))
{
fnFindFile_ShortName(x-1,item,startcluster,fp);
filenumber++;
i=0;
while(1)
{
if(__tolower(filename[i])!=__tolower(fp->filename[i]))
{
break;
}
if(filename[i]=='\0')
{
return fp;
}
i++;
}
stringnum = 0;
name_size = 0;
next_num =0 ;
}
}
}// end of for
}
}
free(fp);
return fp;
}
/******************************************************************
* Function : fnReadFile
* Description : read a file into data buffer
* Input :
* BYTE *buffer-data buffer addess
* BYTE size-size of data entry
* DWORD count -number of data entry
* FILE_t *fp-file pointer
* Return :DWORD count of reading data
*******************************************************************/
DWORD fnReadFile(BYTE *buffer, BYTE size, DWORD count, FILE_t *fp)
{
DWORD read_num;
DWORD offset,sp1,sp2,length;
DWORD bytepercluster = current_fs->byte_per_cluster;
DWORD bytepersector = current_fs->bpb.byte_per_sector;
BYTE *rbuffer;
DWORD remain;
rbuffer=buffers.currentsector.u8data;
//which sector *fp locates
offset=fp->curp/bytepersector;
//sp1 is starting address of target sector
sp1=fp->curp-offset*bytepersector;
read_num=size*count;
//counting reading data, cut data if overflow
if((read_num+fp->curp)>fp->filesize)
{
read_num=fp->filesize-fp->curp;
}
//length: numbers of Byte will be read next operation
//if length more than one sector, cut length or do next reading operation?? 快捷鍵說明
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