Fat.h

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#ifndef __FAT_H__
#define __FAT_H__
 
#include <stdint.h>
#include <Fs/vdisk.h>
#ifdef ARCH_X64
#include <Sync/mutex.h>
#endif
#include <Fs/vfs.h>
 
#define FAT_ATTRIBUTE_MASK  0x3F
#define FAT_ATTRIBUTE_READ_ONLY  0x01
#define FAT_ATTRIBUTE_HIDDEN     0x02
#define FAT_ATTRIBUTE_SYSTEM     0x04
#define FAT_ATTRIBUTE_VOLUME     0x08
#define FAT_ATTRIBUTE_DIRECTORY  0x10
#define FAT_ATTRIBUTE_ARCHIVE    0x20
#define FAT_ATTRIBUTE_LONG_NAME  0x0F
 
#define FAT_EOC_MARK  0xFFFFFFF8
#define FAT_BAD_CLUSTER 0xFFFFFFF7
 
/* FAT32 end-of-chain marks span 0x0FFFFFF8-0x0FFFFFFF, and mkfs/mtools
 * terminate chains with 0x0FFFFFFF. Equality against FAT_EOC_MARK alone
 * misses that terminator, so cluster-chain walks must use this range
 * test -- otherwise they step off the end of the chain and loop forever. */
#define FAT_IS_EOC(clust) ((((uint32_t)(clust)) & 0x0FFFFFFF) >= (FAT_EOC_MARK & 0x0FFFFFFF))
 
 
#ifdef ARCH_X64
#pragma pack(push,1)
#endif
/* FAT BPB */
typedef struct _FAT_BPB_ {
    uint8_t jmp[3]; 
    char    oemid[8]; //0x03 -- 8
    uint16_t bytes_per_sector; //0x00B 2
    uint8_t  sectors_per_cluster; //0x00D 1
    uint16_t reserved_sectors; //0x00E  2
    uint8_t  num_fats; //0x010  1
    uint16_t num_dir_entries; //0x011 2
    uint16_t total_sectors_short; //0x013 2
    uint8_t  media_type; //0x015 1
    uint16_t sectors_per_fat; //0x016 2
    uint16_t sectors_per_track; //0x018 2
    uint16_t heads; //0x01A 2
    uint32_t hidden_sectors; //0x01C 4
    uint32_t large_sector_count; //0x020 4
    union {
        struct {
            uint8_t  drive_num; 
            uint8_t  WinNtFlags;
            uint8_t  signature;
            uint32_t vol_serial_num;
            char     vol_label[11];
            char     sys_id[8];
        }FAT16;
 
        struct {
            uint32_t sect_per_fat32; //0x024  4
            uint16_t falgs; //0x028 2
            uint16_t fat_version; //0x02A 2
            uint32_t root_dir_cluster; //0x02C 4
            uint16_t fs_info_sect; //0x030 2
            uint16_t backup_boot_sect; //0x032 2
            uint8_t  reserved[12]; //0x034 12
            uint8_t  drive_number; //0x040 1
            uint8_t  flagsWinNT; //0x041 1
            uint8_t  signature; //0x042 1
            uint32_t vol_serial_num; //0x043 4
            char     vol_label[11]; //0x047 11
            char     sys_id[8]; //0x052 8
        }FAT32;
    }info;
}FatBPB;
#ifdef ARCH_X64
#pragma pack(pop)
#endif
 
#pragma pack (push, 1)
typedef struct _fat_dir_
{
    uint8_t  filename[11];
    uint8_t  attrib;
    uint8_t  reserved;
    uint8_t  time_created_ms;
    uint16_t time_created;
    uint16_t date_created;
    uint16_t date_last_accessed;
    uint16_t first_cluster_hi_bytes;
    uint16_t last_wrt_time;
    uint16_t last_wrt_date;
    uint16_t first_cluster;
    uint32_t file_size;
}FatDir;
#pragma pack(pop)
 
/*
 * Long file name entry
 */
#pragma pack(push,1)
typedef struct _fat_lfn_ {
    uint8_t order;
    uint8_t nameOne[10];
    uint8_t attrib;
    uint8_t type;
    uint8_t checkSum;
    uint8_t nameTwo[12];
    uint16_t FstClusterLo;
    uint8_t nameThree[4];
}FatLFN;
#pragma pack(pop)
 
#define FSTYPE_FAT12  1
#define FSTYPE_FAT16  2
#define FSTYPE_FAT32  3
 
 
typedef struct _FatFS_ {
    FatBPB* bpb;
    AuVDisk *vdisk;
    char oemid[8];
    uint8_t fatType;
    unsigned long __FatBeginLBA;
    unsigned long __ClusterBeginLBA;
    unsigned char __SectorPerCluster;
    unsigned int __RootDirFirstCluster;
    unsigned long __RootSector;
    unsigned int __SectorPerFAT32;
    unsigned int __TotalClusters;
    unsigned char* __RootDirCache;
    unsigned int __LastIndexSector;
    unsigned int __LastIndexInFat;
    uint16_t __BytesPerSector;
    size_t cluster_sz_in_bytes;
    void* _scratchBuffer;
#ifdef ARCH_X64
    AuMutex *fat_mutex;
    AuMutex *fat_write_mutex;
    AuMutex *fat_read_mutex;
#endif
}FatFS;
 
 
 
/*
* FatInitialise -- initialise the fat file system
* @param vdisk -- Pointer to vdisk structure
* @param mountpoint -- mount point name
*/
extern AuVFSNode* FatInitialise(AuVDisk *vdisk, char* mountpoint);
 
/*
* FatClusterToSector32 -- Converts a cluster to sector
* @param cluster -- cluster number
*/
extern uint64_t FatClusterToSector32(FatFS *fs, uint64_t cluster);
 
extern void FatToDOSFilename(const char* filename, char* fname, unsigned int fname_length);
 
/*
 * FatCalculateCheckSum -- returns an unsigned byte checksum computed on an
 * unsigned byte array. The array must be 11 bytes long and is assumed to
 * contain a name stored in the format of a MS-DOS directory entry
 * @param filename -- Pointer to an unsigned byte array assumed to be
 *                    11 bytes long
 */
extern uint8_t FatCalculateCheckSum(uint8_t* filename);
 
/*
 * FatCheckDotCount -- checks the number of '.' dot
 * count in a given filename
 * @param filename -- name of the file to check
 */
extern uint8_t FatCheckDotCount(char* filename);
 
/*
* FatFindFreeCluster -- finds a free cluster from FAT
* data structure
* @param node -- fs node
*/
extern uint32_t FatFindFreeCluster(AuVFSNode* node);
 
/*
* FatAllocCluster -- allocates a cluster by writing
* n_value
* @param fsys -- Pointer to file system node
* @param position -- position of the cluster
* @param n_value -- value to write
*/
extern void FatAllocCluster(AuVFSNode* fsys, int position, uint32_t n_value);
 
extern void FatClearCluster(AuVFSNode* node, uint32_t cluster);
 
/*
* FatReadFAT -- read the file allocation table
* @param vdisk -- pointer to vdisk
* @param cluster_index -- index of the cluster
*/
extern uint32_t FatReadFAT(AuVFSNode *node, uint64_t cluster_index);
 
extern AuVFSNode * FatOpen(AuVFSNode * fsys, char* filename);
 
/*
* FatFormatDate -- returns fat formated date stamp
*/
extern uint16_t FatFormatDate();
 
/*
* FatFormatTime -- returns fat formated time stamp
*/
extern uint16_t FatFormatTime();
 
 
AuVFSNode* FatLocateDir(AuVFSNode* fsys, const char* dir);
 
AuVFSNode* FatLocateSubDir(AuVFSNode* fsys, AuVFSNode* kfile, const char* filename);
 
/*
* FatFromDosToFilename -- converts fat directoy entry filename
* to human readable filename
*/
extern void FatFromDosToFilename(char* filename, char* dirfname);
 
#endif