TCP/IP Stack, FAT16 System on a Microcontroller

/*
 * myfat.h
 *
 *  Created on: 29/07/2011
 *      Author: lyl
 */

#ifndef MYFAT_H_
#define MYFAT_H_

#define FAT_INIT_OK							0
#define FAT_INIT_MEDIA_ACCESS_ERROR			(-1)
#define FAT_INIT_INVALID_SECTOR_SIZE		(-2)
#define FAT_INIT_INVALID_SIGNATURE			(-3)
#define FAT_INIT_ENDIAN_ERROR				(-4)
#define FAT_INIT_WRONG_FILESYS_TYPE			(-5)
#define FAT_INIT_WRONG_PARTITION_TYPE		(-6)

#define FAT_SECTOR_SIZE						512
#define SIGNATURE_VALUE						0xAA55
#define FAT_DIR_ENTRY_SIZE					32
// Max filename Length 
#define FATFS_MAX_LONG_FILENAME				260

#define FAT_DIR_ENTRIES_PER_SECTOR			(FAT_SECTOR_SIZE / FAT_DIR_ENTRY_SIZE)

#define FAT32_LAST_CLUSTER		0xFFFFFFFF
#define FAT32_INVALID_CLUSTER	0xFFFFFFFF

#define FILE_ATTR_READ_ONLY   	0x01
#define FILE_ATTR_HIDDEN 		0x02
#define FILE_ATTR_SYSTEM 		0x04
#define FILE_ATTR_SYSHID		0x06
#define FILE_ATTR_VOLUME_ID 	0x08
#define FILE_ATTR_DIRECTORY		0x10
#define FILE_ATTR_ARCHIVE  		0x20
#define FILE_ATTR_LFN_TEXT		0x0F
#define FILE_HEADER_BLANK		0x00
#define FILE_HEADER_DELETED		0xE5
#define FILE_TYPE_DIR			0x10
#define FILE_TYPE_FILE			0x20

typedef enum 
{
	FAT_TYPE_16,
	FAT_TYPE_32
} FAT_TYPE;

typedef struct{
	BYTE	boot[446];
}__attribute__((packed)) BOOT_CODE;

typedef struct{
	BYTE	jmp[3];
	BYTE	oem_name[8];
	WORD	bytes_per_sector;
	BYTE	sectors_per_cluster;
	WORD	reserved_sectors;
	BYTE	number_of_fats;
	WORD	number_of_root_entries;
	WORD	total_sectors_low;
	BYTE	media_descriptor;
	WORD	number_of_sectors_per_fat;
} __attribute__((packed)) BOOT_SECTOR_DETAIL;

typedef struct{
	union{
		BYTE data[FAT_SECTOR_SIZE];
		BOOT_SECTOR_DETAIL detail;
	} value;
} __attribute__((packed)) BOOT_SECTOR;

typedef struct{
	BYTE	boot_desc;
	BYTE	first_partition[3];
	BYTE	file_system_desc;
	BYTE	last_partition[3];
	DWORD	num_sectors_before_first;
	DWORD	num_sectors_in_partition;
}__attribute__((packed)) PARTITION_ENTRY;

typedef struct{
	BOOT_CODE boot_section;
	PARTITION_ENTRY entry[4];
	WORD	  boot_signature;//0x55aa
}__attribute__((packed)) MBR;

typedef struct {
	BYTE Name[11];
	BYTE Attr;
	BYTE NTRes;
	BYTE CrtTimeTenth;
	BYTE CrtTime[2];
	BYTE CrtDate[2];
	BYTE LstAccDate[2];
	WORD first_cluster_hi;
	BYTE WrtTime[2];
	BYTE WrtDate[2];
	WORD first_cluster_low;
	DWORD file_size;
} __attribute__((packed)) FAT_FILE_ENTRY;

//MY OWN PROGRAM RUNNING STRUCTURES
struct _SECTOR_BUFFER;

typedef struct _SECTOR_BUFFER
{
	BYTE		buffer[FAT_SECTOR_SIZE];
	DWORD		address; 
	BYTE		dirty;

	struct _SECTOR_BUFFER  *next;
} SECTOR_BUFFER;

typedef struct
{
	BYTE					sectors_per_cluster;
	DWORD					cluster_begin_lba;
	DWORD					rootdir_first_cluster;
	DWORD					rootdir_first_sector;
	DWORD					rootdir_sectors;
	DWORD					fat_begin_lba;
	WORD					fs_info_sector;
	DWORD					lba_begin;
	DWORD					fat_sectors;
	DWORD					next_free_cluster;
	WORD					root_entry_count;
	WORD					reserved_sectors;
	BYTE					num_of_fats;
	FAT_TYPE				fat_type;

	SECTOR_BUFFER			current_sector;
} FAT_SYSTEM;


typedef struct 
{
	DWORD					sector;
	DWORD					cluster;
	unsigned char			offset;
} DIR_STATUS;

typedef struct
{
	char					filename[FATFS_MAX_LONG_FILENAME];
	BOOL					is_dir;
	DWORD					cluster;
	DWORD					size;
} FAT_DIR_ENTRY;

#endif /* MYFAT_H_ */