fat.h

在51下的外挂硬盘和FLASH的MP3方案程序以及原理图

/********************************************************/
/*                                                      */
/*  库   名   称：FAT文件系统函数库                   */

/*  功 能  描 述：提供对FAT文件系统按文件名存取       */
/*                                                      */
/*                                                      */
/********************************************************/

#ifndef _TYPE_DEFINE
 #define _TYPE_DEFINE
 typedef bit BOOL;
 typedef unsigned char BYTE;
 typedef unsigned char CHAR;
 typedef unsigned int WORD;
 typedef unsigned long DWORD;
#endif

#ifndef _FAT_DEFINE
 #define _FAT_DEFINE

#define FAT_MAX_FCB						2

//文件属性
#define	FAT_ATTR_READ_ONLY				0x01			//文件属性：只读
#define	FAT_ATTR_HIDDEN					0x02			//文件属性：隐含
#define	FAT_ATTR_SYSTEM					0x04			//文件属性：系统
#define	FAT_ATTR_VOLUME_ID				0x08			//文件属性：卷ID
#define	FAT_ATTR_DIRECTORY				0x10			//文件属性：目录
#define	FAT_ATTR_ARCHIVE				0x20			//文件属性：归档
#define FAT_ATTR_LONG_NAME				FAT_ATTR_READ_ONLY+FAT_ATTR_HIDDEN+FAT_ATTR_SYSTEM+FAT_ATTR_VOLUME_ID	//文件属性：长文件名
#define FAT_ATTR_LONG_NAME_MASK			FAT_ATTR_READ_ONLY+FAT_ATTR_HIDDEN+FAT_ATTR_SYSTEM+FAT_ATTR_VOLUME_ID+FAT_ATTR_DIRECTORY+FAT_ATTR_ARCHIVE	//文件属性：长文件名
#define FAT_LAST_LONG_ENTRY				0x40			//长文件名入口标记

#define FAT_ERR_MBR_FLAG				0x01			//MBR扇区标志错误	FATMountPartition
#define FAT_ERR_PARTITION_NOT_FOUND		0x02			//指定分区没找到	FATMountVolumeID
#define FAT_ERR_FILE_OPEN_ERROR			FAT_MAX_FCB		//文件打开错误
#define FAT_ERR_DIR_NOT_FOUND			0x01			//指定的目录入口没有找到F	FATChangeDirectory
#define FAT_ERR_NOT_DIR					0x02			//不是一个目录入口		FATChangeDirectory

#define FAT_SEEK_BEGIN					0x01
#define FAT_SEEK_CURRENT				0x02
#define FAT_SEEK_END					0x03

#define FAT_TYPE_FAT12					0x01
#define FAT_TYPE_FAT16					0x02
#define FAT_TYPE_FAT32					0x03

#define FAT_CLUSTER_END32				0xffffffff		//簇链终点
#define FAT_CLUSTER_END16				0xffff			//簇链终点
#define FAT_CLUSTER_END12				0xfff			//簇链终点
#define FAT_CLUSTER_RESERVED32			0xfffffff6		//保留簇
#define FAT_CLUSTER_RESERVED16			0xfff6			//保留簇
#define FAT_CLUSTER_RESERVED12			0xff6			//保留簇
#define FAT_CLUSTER_BAD32				0xfffffff7		//坏簇
#define FAT_CLUSTER_BAD16				0xfff7			//坏簇
#define FAT_CLUSTER_BAD12				0xff7			//坏簇

#define FAT_MASK_FAT32					0x0fffffff
#define FAT_MASK_FAT16					0x0000ffff
#define FAT_MASK_FAT12					0x00000fff

#define FAT_MAX_PARTITIONS				0x10
//#define IO_ERROR						0x00				//遇到io错误
//#define NO_IO_ERROR					0x01				//没有遇到io错误

//计算指定簇的开始扇区号
#define ClusterToSector(X)			FAT.ClusSec + (X - 2) * FAT.SecPerClus

struct StorageMediaStr
{
	WORD	BytesPerSec;			//每扇区字节数
	DWORD	TotalSectors;			//总扇区数
	BYTE	TotalPartitions;		//分区数
	BYTE	CurrentPartition;		//当前分区
	BYTE	(*ReadSector)(DWORD Sector,BYTE *Buffer);
	BYTE	(*WriteSector)(DWORD Sector,BYTE *Buffer);
};

struct BootSecFAT16Str					//引导扇区   FAT16  扩展结构
{
	BYTE	BS_DrvNum;
	BYTE	BS_Reserved1;
	BYTE	BS_BootSig;
	DWORD	BS_VolID;
	char	BS_VolLab[11];
	char	BS_FilSysType[8];
};

struct BootSecFAT32Str					//引导扇区   FAT  扩展结构
{
	DWORD	BPB_FATSz32;			//FAT扇区总数
	WORD	BPB_ExtFlags;
	WORD	BPB_FSVer;
	DWORD	BPB_RootClus;			//根目录开始的簇
	WORD	BPB_FSInfo;
	WORD	BPB_BkBootSec;
	char	BPB_Reserved[12];
	BYTE	BS_DrvNum;
	BYTE	BS_Reserved1;
	BYTE	BS_BootSig;
	DWORD	BS_VolID;
	char	BS_VolLab[11];
	char	BS_FilSysType[8];
};

struct BootSecStr						//引导扇区结构
{
	BYTE	BS_jmpBoot[3];
	BYTE	BS_OEMName[8];
	WORD	BPB_BytesPerSec;		//每扇区字节数  512
	BYTE	BPB_SecPerClus;			//每簇扇区数	1 2 4 8 16 32 64 128
	WORD	BPB_RsvdSecCnt;			//保留扇区数	0x20
	BYTE	BPB_NumFATs;			//FAT表个数		2
	WORD	BPB_RootEntCnt;		
	WORD	BPB_TotSec16;
	BYTE	BPB_Media;
	WORD	BPB_FATSz16;
	WORD	BPB_SecPerTrk;
	WORD	BPB_NumHeads;
	DWORD	BPB_HiddSec;
	DWORD	BPB_TotSec32;
	union	FATUni
	{
		struct BootSecFAT32Str	F32;
		struct BootSecFAT16Str	F16;
	}FAT;

};

struct DPTStr				//分区表结构
{
	BYTE	BootFlag;
	BYTE	CHSBegin[3];
	BYTE	TypeCode;
	BYTE	CHSEnd[3];
	DWORD	LBABegin;
	DWORD	CntSec;
};

struct sDPTStr				//简化的分区表
{
	BYTE	FATType;
	DWORD	LBABegin;
	DWORD	CntSec;
};

struct FAT32FSInfoStr		//FAT32扩展信息结构
{
	DWORD	LeadSig;
	BYTE	Reserved1[480];
	DWORD	StrucSig;
	DWORD	FreeCount;
	DWORD	NxtFree;
	BYTE	Reserved2[12];
	DWORD	TrailSig;
};

struct FATSDirStr			//FAT目录结构 短文件名
{
	CHAR	Name[11];
	BYTE	Attr;
	BYTE	NTRes;
	BYTE	CrtTimeTenth;
	WORD	CrtTime;
	WORD	CrtDate;
	WORD	LstAccDate;
	WORD	FstClusHI;
	WORD	WrtTime;
	WORD	WrtDate;
	WORD	FstClusLO;
	DWORD	FileSize;
};

struct FATLDirStr			//FAT目录结构 长文件名
{
	BYTE	Ord;
	BYTE	Name1[10];
	BYTE	Attr;
	BYTE	Type;
	BYTE	Chksum;
	BYTE	Name2[12];
	WORD	FstClusLO;
	BYTE	Name3[4];
};

struct FATStr					//FAT参数表
{
//	BYTE	ClusSecCnt;			//当前簇扇区计数
	DWORD	CurrentDirectory;	//当前目录入口（簇号）
	BYTE	SecPerClus;			//每簇扇区数	1 2 4 8 16 32 64 128
	DWORD	RootClus;			//根目录开始的簇
	BYTE	RootSectors;		//根目录占用的扇区数
	DWORD	ClusSec;			//簇开始的扇区
	DWORD	FATSz;				//FAT表大小（扇区）
	DWORD	FATSec;				//FAT表开始扇区
	DWORD	FSISec;				//FSI所在扇区
	DWORD	FSIFreeCount;		//空闲簇数
	DWORD	FSINxtFree;			//空闲簇搜索指针
};

struct FCBStr
{
	CHAR	FileName[12];		//文件名
	DWORD	Size;				//文件大小
	DWORD	FirstCluster;		//第一个簇
	DWORD	LastCluster;		//最近一次读到的簇号
	DWORD	ClusSecCnt;			//当前簇扇区计数
	DWORD	ByteCnt;			//当前字节计数
};

struct FATTableStr
{
	DWORD	Sector;
	union FATUin
	{
		DWORD	F32[128];
		WORD	F16[256];
		BYTE	F12[512];
	}FAT;
};

struct FATClusterStr
{
	BYTE	SecOffset;				//扇区偏移量
	DWORD	Sector;				//扇区号
	DWORD	Cluster;			//簇号
};

#ifndef _LIBRARY_DEFINE
 xdata BYTE DiskBuffer[512];

 xdata struct StorageMediaStr StorageMedia;
 xdata struct sDPTStr sDPT[FAT_MAX_PARTITIONS];
 xdata struct FATStr FAT;
 xdata struct FCBStr FCB[FAT_MAX_FCB];
 xdata CHAR LongFileName[256]; 
 xdata struct FATTableStr FATTable;
 xdata struct DPTStr *DPT;			//分区表结构指针
 xdata struct BootSecStr *BOOTSEC;		//引导扇区结构指针
 xdata struct FAT32FSInfoStr *FSI;		//FAT32扩展信息
 xdata struct FATSDirStr *sDIR;		//FAT目录结构指针
 xdata struct FATLDirStr *lDIR;		//FAT目录结构指针
#endif
#endif

extern xdata BYTE DiskBuffer[512];

extern xdata struct StorageMediaStr StorageMedia;
extern xdata struct sDPTStr sDPT[FAT_MAX_PARTITIONS];
extern xdata struct FATStr FAT;
extern xdata struct FCBStr FCB[FAT_MAX_FCB];
extern xdata CHAR LongFileName[256]; 
extern xdata struct FATTableStr FATTable;
extern xdata struct DPTStr *DPT;		//分区表结构指针
extern xdata struct BootSecStr *BOOTSEC;	//引导扇区结构指针
extern xdata struct FAT32FSInfoStr *FSI;	//FAT32扩展信息
extern xdata struct FATSDirStr *sDIR;		//FAT目录结构指针
extern xdata struct FATLDirStr *lDIR;		//FAT目录结构指针

extern void FATInit(void);
extern BYTE FATSelectMedia(BYTE Media);
extern BYTE FATFindPartitions(void);
extern BYTE FATMountPartition(void);
extern BYTE FATMountVolumeID(BYTE Partition);
extern void FATGetPartLongName(struct FATLDirStr *ldp,CHAR *name);
extern DWORD FATDiskSize(void);
extern DWORD FATDiskFreeSize(void);
extern BYTE FATFindDIREntry(CHAR *DirName);
extern BYTE FAT32FindDIREntry(CHAR *DirName);
extern BYTE FAT16FindDIREntry(CHAR *DirName);
void FATReadCluster(struct FATClusterStr *Cluster,BYTE *Buffer);
extern BYTE FATChangeDirectory(CHAR *DirName);
extern BYTE FATListDirectory(void);
extern BYTE FAT32ListDirectory(void);
extern BYTE FAT16ListDirectory(void);
extern void FATNextCluster(DWORD *CurrentCluster);
extern BYTE FATGetDirName(WORD SecNum);
extern BYTE FATOpenFile(CHAR *filename);
extern void FATCloseFile(BYTE fp);
extern WORD FATReadFile(BYTE fp);