fat16.h

Go to the documentation of this file.

#ifndef __fat16_h
#define __fat16_h

//________________________________________________________________________________________________________________________________________
// 
// Structure of a filepointer
//                              
//________________________________________________________________________________________________________________________________________

typedef struct afile
{
        unsigned long   start_cluster;                          // Sectorpointer to the first sector of the first datacluster of the file. 
        unsigned long   cluster_pointer;                        // Pointer to the cluster which is edited at the moment.
        unsigned char   sector_index;                           // The sector which is edited at the moment (cluster_pointer + sector_index).
        unsigned int    byte_index;                                     // The bytelocation within the current sector (cluster_pointer + sector_index + byte_index).
        unsigned char   mode;                                           // mode of fileoperation (read,write)
        unsigned long  filesize;                                        // the size of the opend file in bytes.
        unsigned long  fileposition;                            // pointer to a character within the file 0 < fileposition < filesize
        unsigned long  sector_in_buffer;                        // the last sector read, wich is still in the sectorbuffer.
        unsigned long  directory_sector;                        // the sectorposition where the directoryentry has been made.
        unsigned char  directory_index;                 // the index to the directoryentry within the specified sector.
        unsigned char  attribute;                                       // the attribute of the file opened.
} File;

//________________________________________________________________________________________________________________________________________
// 
// Structure of an directoryentry
//                              
//________________________________________________________________________________________________________________________________________

struct DirEntry
{
        unsigned char name[8];                                          // 8 bytes name.
        unsigned char extension[3];                             // 3 bytes extension.
        unsigned char attribute;                                        // attribute of the directory entry (unused,archive,read-only,system,directory,volume)
        unsigned char reserved[10];
        unsigned int  time;                                             // time and
        unsigned int  date;                                             // date of last write acces to the file or directory.
        unsigned int  startcluster;                             // first cluster of the file or directory.
        unsigned long size;                                             // size of the file or directory in bytes.
};

//________________________________________________________________________________________________________________________________________
// 
// Structure of an entry within the fileallocationtable.
//                              
//________________________________________________________________________________________________________________________________________

struct FatEntry
{
        unsigned int  next_cluster;                             // the next cluster of the file.
};
//________________________________________________________________________________________________________________________________________
// 
// API to the FAT16 filesystem
//                              
//________________________________________________________________________________________________________________________________________

extern unsigned char    InitFat16(void);                
extern unsigned char    fopen_(unsigned char *fname,char mode, File *file);
extern int                              fflush_(File *file);
extern void                     fclose_(File *file);
extern unsigned long    fread_(void *buffer, unsigned long size, unsigned long count, File *file); 
extern unsigned long    fwrite_(void *buffer, unsigned long size, unsigned long count, File *file);
extern int                      fseek_(File *file, long offset, int origin);
extern           int    fgetchar_(File *file);
extern unsigned char    fputchar_(File *file,char c);
extern unsigned char    fputs_(File *file,char *string);
extern char *           fgets_(char *s, int count, File *file);
extern int                              rename(char *oldname, char *newname);
extern unsigned char  fexist_(unsigned char *fname, File *file);

//________________________________________________________________________________________________________________________________________
// 
// Functions needed internaly for the fat16 implementation 
//                              
//________________________________________________________________________________________________________________________________________

extern unsigned char    CreateDirectoryEntry(unsigned char *fname, unsigned int cluster, File *file,unsigned char attrib);
extern unsigned int     FindNextFreeCluster(File *file);
extern unsigned char    SeekDirectoryEntry(unsigned char *fname, File *file);
extern void                     SeperateFileName(unsigned char *fname, unsigned char *name);
extern unsigned char  ScanSubDirectories(unsigned char *fname, File *file);
extern unsigned int   GetNextCluster(File *file);
extern unsigned char  AppendCluster(File *file);
extern unsigned int     GetFatClusterOffset(File *file);
extern unsigned int     GetFatSectorIndex(File *file);


//________________________________________________________________________________________________________________________________________
// 
// Definitions
//                              
//________________________________________________________________________________________________________________________________________

//#define               __USE_TIME_DATE_ATTRIBUTE
#define         MBR_SECTOR                                      0               // the masterboot record is located in sector 0.
#define         _UNUSED         1                                               // Bits used in the attribute of an directory entry.
#define         _ARCHIVE        2
#define         _READ_ONLY      4
#define         _SYSTEM         8
#define         _DIRECTORY      16
#define         _FILE           32

//________________________________________________________________________________________________________________________________________
// 
// Vaiables needed internaly for the fat16 implementation 
//                              
//________________________________________________________________________________________________________________________________________

extern unsigned char    SectorsPerCluster;
extern unsigned char    FileBuffer[512];
extern unsigned char    SectorsPerCluster;
extern File myfile;

//extern struct   time  rtctime;
#endif