/*
 * fat.h
 *
 *  Created on: Aug 31, 2011
 *      Author: Tiberiu
 */

#ifndef FAT_H_
#define FAT_H_

#include <fileio.h>

/*******************************************************
 * FAT: Bios Parameter Block                           *
 *******************************************************/
typedef struct {
	uint8 AsmJmp[3];
	char OemId[8];
	uint16 BytesPerSector;
	uint8 SectorsPerCluster;
	uint16 ReservedSectors;
	uint8 FatsCount;
	uint16 DirectoryEntriesCount;
	uint16 TotalSectors;
	uint8 MediaDescriptorType;
	uint32 SectorsPerFat;
	uint16 SectorsPerTrack;
	uint16 Heads;
	uint32 HiddenSectors;
	uint32 TotalSectorsLarge;
} __attribute__((packed)) FatBiosParameterBlock ;

/*******************************************************
 * FAT12/FAT16: Extended boot record                   *
 *******************************************************/
typedef struct {
	uint8 DriveNumber;	// Useless
	uint8 NtFlags;
	uint8 Signature;	// Must be 0x28/0x29
	uint32 VolumeIdSerial;
	char VolumeLabel[11];
	char SystemId[8];
} __attribute__((packed)) Fat16ExtendedBootRecord; // fat12 or 16

/*******************************************************
 * FAT32: Extended boot record                         *
 *******************************************************/
typedef struct {
	uint32 SectorsPerFat;
	uint16 Flags;
	uint16 FatVersion; // High byte=major version, low=minor
	uint32 RootDirectoryCluster;
	uint16 FsInfoCluster;
	uint16 BackupBootSectorCluster;
	uint8 Reserved[12];	// Should be set to 0 when formatting
	uint8 DriveNumber;
	uint8 NtFlags;
	uint8 Signature; 	// Must be 0x28/0x29
	uint32 VolumeIdSerial;
	char VolumeLabel[11];
	char SystemId[8];	// Always "FAT32   "
} __attribute__((packed)) Fat32ExtendedBootRecord;

/*******************************************************
 * FAT: Extended boot record (union of above 2 fields) *
 *******************************************************/
union FatExtendedBootRecord
{
	Fat16ExtendedBootRecord fat16;
	Fat32ExtendedBootRecord fat32;
};

/*******************************************************
 * FAT: Complete boot sector info                      *
 *******************************************************/
typedef struct {
	FatBiosParameterBlock bpb;
	union FatExtendedBootRecord ext;
} __attribute__((packed)) FatBootSector;


/*******************************************************
 * FAT: Directory entry                                *
 *******************************************************/
typedef struct {
	char FileName[8];
	char FileExt[3];
	uint8 Attributes;
	uint8 _reserved;
	uint8 CreateTimeFine; // hundreds (0.01) of a second, up to 199
	uint16 CreateTime;	  // 15-11 hour; 10-5 mins; 4-0 secs/2;
	uint16 CreateDate;	  // 15-9 year (since 1980); 8-5 mon; 4-0 day
	uint16 AccessDate;

	uint16 FirstClusterHigh; // Fat32; EA-index in fat12,fat16

	uint16 LastModifiedTime;
	uint16 LastModifiedDate;

	uint16 FirstClusterLow;
	uint32 Size;
} __attribute__((packed)) FatDirectoryEntry;


/*******************************************************
 * FAT: Long file name entry                           *
 *******************************************************/
typedef struct {
	uint8 SequenceNo;
	uint16 Name1[5];	// Encoded in UTF-16
	uint8 Attributes;	// Should be 0xF;
	uint8 _reserved;
	uint16 Name2[6];
	uint16 FirstCluster;// Should be 0x0000
	uint16 Name3[2];
} FatLongFileName;


/*******************************************************
 * FAT: Directory entry (union of above 2 fields)      *
 *******************************************************/
union FatDirEntryUnion {
	FatDirectoryEntry d;
	FatLongFileName lfn;
};


extern uint32 FatDetect (void* buffer);
extern void FatInstall();

extern uint32 Fat12Detect (DevReadRoutine r, uint32 blocksz);
extern uint32 Fat16Detect (DevReadRoutine r, uint32 blocksz);
extern uint32 Fat32Detect (DevReadRoutine r, uint32 blocksz);

#endif /* FAT_H_ */