#ifndef __FAT_H__
#define __FAT_H__		    	
#include "COMM.H"	    
#include <string.h>
	  																	    
#define MSDOSFSROOT     0               // cluster 0 means the root dir
#define CLUST_FREE      0               // cluster 0 also means a free cluster
#define MSDOSFSFREE     CLUST_FREE
#define CLUST_FIRST     2             	// first legal cluster number
#define CLUST_RSRVD     0xfff6      	// reserved cluster range
#define CLUST_BAD       0xfff7     		// a cluster with a defect
#define CLUST_EOFS      0xfff8     		// start of eof cluster range
#define CLUST_EOFE      0xffff      	// end of eof cluster range

//dir_clust:當前目錄簇號
//FileInfo: 文件指針
//type:     要瀏覽的文件類型
//返回值:   當前文件索引
//文件夾中 ".":代表當前目錄,"..":代表上一級目錄
//文件目錄項的文件屬性位
#define	AM_RDO	0x01	//只讀文件
#define	AM_HID	0x02	//隱藏文件
#define	AM_SYS	0x04	//系統(tǒng)文件
#define	AM_VOL	0x08	//卷標
#define AM_LFN	0x0F	//長文件名字段
#define AM_DIR	0x10	//文件夾
#define AM_ARC	0x20	//歸檔文件
//使用packed 以字節(jié)分配.避免數(shù)據(jù)對齊的問題
typedef __packed struct  // length 16 bytes
{			
	BYTE	prIsActive;					// 0x80 indicates active partition
	BYTE	prStartHead;				// starting head for partition
	WORD	prStartCylSect;				// starting cylinder and sector
	BYTE	prPartType;					// partition type (see above)
	BYTE	prEndHead;					// ending head for this partition
	WORD	prEndCylSect;				// ending cylinder and sector
	DWORD	prStartLBA;					// first LBA sector for this partition
	DWORD	prSize;						// size of this partition (bytes or sectors ?)
}partrecord;  
     
typedef __packed struct 
{
	BYTE	psPartCode[512-64-2];		// pad so struct is 512b
	BYTE	psPart[64];					// four partition records (64 bytes)
	BYTE	psBootSectSig0;				// two signature bytes (2 bytes)
	BYTE	psBootSectSig1;
#define BOOTSIG0        0x55
#define BOOTSIG1        0xaa
}partsector;

typedef __packed struct  
{
	BYTE	exDriveNumber;				// drive number (0x80)//0x00 for floopy disk 0x80 for hard disk
	BYTE	exReserved1;				// reserved should always set 0
	BYTE	exBootSignature;			// ext. boot signature (0x29)
#define EXBOOTSIG       0x29
	BYTE	exVolumeID[4];				// volume ID number
	BYTE	exVolumeLabel[11];			// volume label "NO NAME"
	BYTE	exFileSysType[8];			// fs type (FAT12 or FAT)
}extboot;

typedef __packed struct 
{
	BYTE	bsJump[3];					// jump inst E9xxxx or EBxx90
	BYTE	bsOemName[8];				// OEM name and version
	BYTE	bsBPB[25];					// BIOS parameter block
	BYTE	bsExt[26];					// Bootsector Extension
	BYTE	bsBootCode[448];			// pad so structure is 512b
	BYTE	bsBootSectSig0;				// boot sector signature byte 0x55 
	BYTE	bsBootSectSig1;				// boot sector signature byte 0xAA
#define BOOTSIG0        0x55
#define BOOTSIG1        0xaa
}bootsector50;


typedef __packed struct
{
        WORD	bpbBytesPerSec; // bytes per sector				//512 1024 2048 or 4096
        BYTE	bpbSecPerClust; // sectors per cluster			// power of 2
        WORD	bpbResSectors;  // number of reserved sectors	//1 is recommend
        BYTE	bpbFATs;        // number of FATs				// 2 is recommend
        WORD	bpbRootDirEnts; // number of root directory entries
        WORD	bpbSectors;     // total number of sectors
        BYTE	bpbMedia;       // media descriptor				//0xf8 match the fat[0]
        WORD	bpbFATsecs;     // number of sectors per FAT
        WORD	bpbSecPerTrack; // sectors per track
        WORD	bpbHeads;       // number of heads
        DWORD	bpbHiddenSecs;  // # of hidden sectors
        DWORD	bpbHugeSectors; // # of sectors if bpbSectors == 0
}bpb50;

typedef __packed struct 
{
	BYTE	bsJump[3];					// jump inst E9xxxx or EBxx90
	BYTE	bsOemName[8];				// OEM name and version
	BYTE	bsBPB[53];					// BIOS parameter block
	BYTE	bsExt[26];					// Bootsector Extension
	BYTE	bsBootCode[418];			// pad so structure is 512b
	BYTE	bsBootSectSig2;				// boot sector signature byte 0x00 
	BYTE	bsBootSectSig3;				// boot sector signature byte 0x00
	BYTE	bsBootSectSig0;				// boot sector signature byte 0x55 
	BYTE	bsBootSectSig1;				// boot sector signature byte 0xAA
#define BOOTSIG0        0x55
#define BOOTSIG1        0xaa
#define BOOTSIG2        0x00
#define BOOTSIG3        0x00
}bootsector710;

typedef __packed struct 
{
		WORD	bpbBytesPerSec;	// bytes per sector
		BYTE	bpbSecPerClust;	// sectors per cluster
		WORD	bpbResSectors;	// number of reserved sectors
		BYTE	bpbFATs;		// number of FATs
		WORD	bpbRootDirEnts;	// number of root directory entries
		WORD	bpbSectors;		// total number of sectors
		BYTE	bpbMedia;		// media descriptor
		WORD	bpbFATsecs;		// number of sectors per FAT
		WORD	bpbSecPerTrack;	// sectors per track
		WORD	bpbHeads;		// number of heads
		DWORD	bpbHiddenSecs;	// # of hidden sectors
// 3.3 compat ends here
		DWORD	bpbHugeSectors;	// # of sectors if bpbSectors == 0
// 5.0 compat ends here
		DWORD     bpbBigFATsecs;// like bpbFATsecs for FAT32
		WORD      bpbExtFlags;	// extended flags:
#define FATNUM    0xf			// mask for numbering active FAT
#define FATMIRROR 0x80			// FAT is mirrored (like it always was)
		WORD      bpbFSVers;	// filesystem version
#define FSVERS    0				// currently only 0 is understood
		DWORD     bpbRootClust;	// start cluster for root directory
		WORD      bpbFSInfo;	// filesystem info structure sector
		WORD      bpbBackup;	// backup boot sector
		// There is a 12 byte filler here, but we ignore it
}bpb710;	  

// 文件結(jié)構(gòu)體
typedef __packed struct
{
		BYTE		deName[8];      	// filename, blank filled
#define SLOT_EMPTY      0x00            // slot has never been used
#define SLOT_E5         0x05            // the real value is 0xE5
#define SLOT_DELETED    0xE5            // file in this slot deleted
#define SLOT_DIR		0x2E			// a directorymmm
		BYTE		deExtension[3]; 	// extension, blank filled
		BYTE		deAttributes;   	// file attributes
#define ATTR_NORMAL     0x00            // 普通文件
#define ATTR_READONLY   0x01            // 只讀文件
#define ATTR_HIDDEN     0x02            // 隱藏文件
#define ATTR_SYSTEM     0x04            // 系統(tǒng)文件
#define ATTR_VOLUME     0x08            // 卷標
#define ATTR_LONG_FILENAME	0x0F		// 長文件名標志			    
#define ATTR_DIRECTORY  0x10            // 文件夾文件
#define ATTR_ARCHIVE    0x20            // 新的或者歸檔文件
		BYTE        deLowerCase;    	// NT VFAT lower case flags  (set to zero)
#define LCASE_BASE      0x08            // filename base in lower case
#define LCASE_EXT       0x10            // filename extension in lower case
		BYTE        deCHundredth;   	// hundredth of seconds in CTime
		BYTE        deCTime[2];     	// create time
		BYTE        deCDate[2];     	// create date
		BYTE        deADate[2];     	// access date
		WORD        deHighClust; 		// high bytes of cluster number
		BYTE        deMTime[2];     	// last update time
		BYTE        deMDate[2];     	// last update date
		WORD        deStartCluster; 	// starting cluster of file
		DWORD       deFileSize;  		// size of file in bytes
}direntry;

// number of directory entries in one sector
#define DIRENTRIES_PER_SECTOR	0x10	//when the bpbBytesPerSec=512 

// Structure of a Win95 long name directory entry
typedef __packed struct 
{
		BYTE			weCnt;			// 
#define WIN_LAST        0x40
#define WIN_CNT         0x3f
		BYTE		wePart1[10];
		BYTE		weAttributes;
#define ATTR_WIN95      0x0f
		BYTE		weReserved1;
		BYTE		weChksum;
		BYTE		wePart2[12];
		WORD       	weReserved2;
		BYTE		wePart3[4];
}winentry;

#define WIN_ENTRY_CHARS	13      // Number of chars per winentry

// Maximum filename length in Win95
// Note: Must be < sizeof(dirent.d_name)
#define WIN_MAXLEN      255

// This is the format of the contents of the deTime field in the direntry
// structure.
// We don't use bitfields because we don't know how compilers for
// arbitrary machines will lay them out.
#define DT_2SECONDS_MASK        0x1F    // seconds divided by 2
#define DT_2SECONDS_SHIFT       0
#define DT_MINUTES_MASK         0x7E0   // minutes
#define DT_MINUTES_SHIFT        5
#define DT_HOURS_MASK           0xF800  // hours
#define DT_HOURS_SHIFT          11

// This is the format of the contents of the deDate field in the direntry
// structure.
#define DD_DAY_MASK				0x1F	// day of month
#define DD_DAY_SHIFT			0
#define DD_MONTH_MASK			0x1E0	// month
#define DD_MONTH_SHIFT			5
#define DD_YEAR_MASK			0xFE00	// year - 1980
#define DD_YEAR_SHIFT			9

//用到的外部函數(shù)
//extern u16 POINT_COLOR;		//畫筆顏色
//extern u16 BACK_COLOR;		//背景顏色
//extern void delay_ms(u16);	  						   
//FAT原有的函數(shù)	    
unsigned char FAT_Init(void);//初始化												  
unsigned long FAT_NextCluster(unsigned long cluster);//查找下一簇號	
u32 fatClustToSect(u32 cluster);//將簇號轉(zhuǎn)換為扇區(qū)號
u8 Get_File_Info(u32 dir_clust,FileInfoStruct *FileInfo,u16 type,u16 *count);//查找文件
void F_Open(FileInfoStruct *FileInfo);//打開文件
unsigned char F_Read(FileInfoStruct *FileInfo,u8 *buf);//讀文件，size=0代表整個文件

unsigned long FAT_OpenDir(BYTE * dir);//打開目錄	  
#endif