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repo2/firmware_legacy/defunct/fat.h

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/*! \file fat.h \brief FAT16/32 file system driver. */
//*****************************************************************************
//
// File Name : 'fat.h'
// Title : FAT16/32 file system driver
// Author : Pascal Stang
// Date : 11/07/2000
// Revised : 12/12/2000
// Version : 0.3
// Target MCU : ATmega103 (should work for Atmel AVR Series)
// Editor Tabs : 4
//
// NOTE: This code is currently below version 1.0, and therefore is considered
// to be lacking in some functionality or documentation, or may not be fully
// tested. Nonetheless, you can expect most functions to work.
//
/// \ingroup general
/// \defgroup fat FAT16/32 File System Interface (fat.c)
/// \code #include "fat.h" \endcode
/// \par Overview
/// This FAT16/32 interface allows you to detect and mount FAT16/32
/// partitions, browse directories and files, and read file data.
/// The interface is designed to operate with the avrlib IDE/ATA driver.
/// Reading FAT efficiently requires at least 512+ bytes of RAM so this
/// interface may not be suitable for processors with less than 1K of RAM.
/// This interface will properly follow a file's cluster chain so files
/// need not be defragmented.
///
/// \note This code is based in part on work done by Jesper Hansen for his
/// excellent YAMPP MP3 player project.
//
// ----------------------------------------------------------------------------
// 17.8.2008
// Bob!k & Raster, C.P.U.
// Original code was modified especially for the SDrive device.
// Some parts of code have been added, removed, rewrited or optimized due to
// lack of MCU AVR Atmega8 memory.
// ----------------------------------------------------------------------------
//
// This code is distributed under the GNU Public License
// which can be found at http://www.gnu.org/licenses/gpl.txt
//
//*****************************************************************************

#ifndef FAT_H
#define FAT_H

#define FALSE 0
#define TRUE -1

#define DRIVE0 1

// Some useful cluster numbers
#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 0xfffffff6 // reserved cluster range
#define CLUST_BAD 0xfffffff7 // a cluster with a defect
#define CLUST_EOFS 0xfffffff8 // start of eof cluster range
#define CLUST_EOFE 0xffffffff // end of eof cluster range

#define FAT12_MASK 0x00000fff // mask for 12 bit cluster numbers
#define FAT16_MASK 0x0000ffff // mask for 16 bit cluster numbers
#define FAT32_MASK 0x0fffffff // mask for FAT32 cluster numbers


// Partition Type used in the partition record
#define PART_TYPE_UNKNOWN 0x00
#define PART_TYPE_FAT12 0x01
#define PART_TYPE_XENIX 0x02
#define PART_TYPE_DOSFAT16 0x04
#define PART_TYPE_EXTDOS 0x05
#define PART_TYPE_FAT16 0x06
#define PART_TYPE_NTFS 0x07
#define PART_TYPE_FAT32 0x0B
#define PART_TYPE_FAT32LBA 0x0C
#define PART_TYPE_FAT16LBA 0x0E
#define PART_TYPE_EXTDOSLBA 0x0F
#define PART_TYPE_ONTRACK 0x33
#define PART_TYPE_NOVELL 0x40
#define PART_TYPE_PCIX 0x4B
#define PART_TYPE_PHOENIXSAVE 0xA0
#define PART_TYPE_CPM 0xDB
#define PART_TYPE_DBFS 0xE0
#define PART_TYPE_BBT 0xFF

struct partrecord // length 16 bytes
{
unsigned char prIsActive; // 0x80 indicates active partition
unsigned char prStartHead; // starting head for partition
unsigned short prStartCylSect; // starting cylinder and sector
unsigned char prPartType; // partition type (see above)
unsigned char prEndHead; // ending head for this partition
unsigned short prEndCylSect; // ending cylinder and sector
unsigned long prStartLBA; // first LBA sector for this partition
unsigned long prSize; // size of this partition (bytes or sectors ?)
};


struct partsector
{
unsigned char psPartCode[512-64-2]; // pad so struct is 512b
unsigned char psPart[64]; // four partition records (64 bytes)
unsigned char psBootSectSig0; // two signature bytes (2 bytes)
unsigned char psBootSectSig1;
#define BOOTSIG0 0x55
#define BOOTSIG1 0xaa
};


// Format of a boot sector. This is the first sector on a DOS floppy disk
// or the first sector of a partition on a hard disk. But, it is not the
// first sector of a partitioned hard disk.
struct bootsector33 {
unsigned char bsJump[3]; // jump inst E9xxxx or EBxx90
unsigned char bsOemName[8]; // OEM name and version
unsigned char bsBPB[19]; // BIOS parameter block
unsigned char bsDriveNumber; // drive number (0x80)
unsigned char bsBootCode[479]; // pad so struct is 512b
unsigned char bsBootSectSig0; // boot sector signature byte 0x55
unsigned char bsBootSectSig1; // boot sector signature byte 0xAA
#define BOOTSIG0 0x55
#define BOOTSIG1 0xaa
};

struct extboot {
unsigned char exDriveNumber; // drive number (0x80)
unsigned char exReserved1; // reserved
unsigned char exBootSignature; // ext. boot signature (0x29)
#define EXBOOTSIG 0x29
unsigned char exVolumeID[4]; // volume ID number
unsigned char exVolumeLabel[11]; // volume label
unsigned char exFileSysType[8]; // fs type (FAT12 or FAT16)
};

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

struct bootsector710 {
unsigned char bsJump[3]; // jump inst E9xxxx or EBxx90
unsigned char bsOEMName[8]; // OEM name and version
unsigned char bsBPB[53]; // BIOS parameter block
unsigned char bsExt[26]; // Bootsector Extension
unsigned char bsBootCode[418]; // pad so structure is 512b
unsigned char bsBootSectSig2; // 2 & 3 are only defined for FAT32?
unsigned char bsBootSectSig3;
unsigned char bsBootSectSig0; // boot sector signature byte 0x55
unsigned char bsBootSectSig1; // boot sector signature byte 0xAA
#define BOOTSIG0 0x55
#define BOOTSIG1 0xaa
#define BOOTSIG2 0
#define BOOTSIG3 0
};


/***************************************************************/
/***************************************************************/

// BIOS Parameter Block (BPB) for DOS 3.3
struct bpb33 {
unsigned short bpbBytesPerSec; // bytes per sector
unsigned char bpbSecPerClust; // sectors per cluster
unsigned short bpbResSectors; // number of reserved sectors
unsigned char bpbFATs; // number of FATs
unsigned short bpbRootDirEnts; // number of root directory entries
unsigned short bpbSectors; // total number of sectors
unsigned char bpbMedia; // media descriptor
unsigned short bpbFATsecs; // number of sectors per FAT
unsigned short bpbSecPerTrack; // sectors per track
unsigned short bpbHeads; // number of heads
unsigned short bpbHiddenSecs; // number of hidden sectors
};

// BPB for DOS 5.0
// The difference is bpbHiddenSecs is a short for DOS 3.3,
// and bpbHugeSectors is not present in the DOS 3.3 bpb.
struct bpb50 {
unsigned short bpbBytesPerSec; // bytes per sector
unsigned char bpbSecPerClust; // sectors per cluster
unsigned short bpbResSectors; // number of reserved sectors
unsigned char bpbFATs; // number of FATs
unsigned short bpbRootDirEnts; // number of root directory entries
unsigned short bpbSectors; // total number of sectors
unsigned char bpbMedia; // media descriptor
unsigned short bpbFATsecs; // number of sectors per FAT
unsigned short bpbSecPerTrack; // sectors per track
unsigned short bpbHeads; // number of heads
unsigned long bpbHiddenSecs; // # of hidden sectors
// 3.3 compat ends here
unsigned long bpbHugeSectors; // # of sectors if bpbSectors == 0
};

// BPB for DOS 7.10 (FAT32)
// This one has a few extensions to bpb50.
struct bpb710 {
unsigned short bpbBytesPerSec; // bytes per sector
unsigned char bpbSecPerClust; // sectors per cluster
unsigned short bpbResSectors; // number of reserved sectors
unsigned char bpbFATs; // number of FATs
unsigned short bpbRootDirEnts; // number of root directory entries
unsigned short bpbSectors; // total number of sectors
unsigned char bpbMedia; // media descriptor
unsigned short bpbFATsecs; // number of sectors per FAT
unsigned short bpbSecPerTrack; // sectors per track
unsigned short bpbHeads; // number of heads
unsigned long bpbHiddenSecs; // # of hidden sectors
// 3.3 compat ends here
unsigned long bpbHugeSectors; // # of sectors if bpbSectors == 0
// 5.0 compat ends here
unsigned long bpbBigFATsecs;// like bpbFATsecs for FAT32
unsigned short bpbExtFlags; // extended flags:
#define FATNUM 0xf // mask for numbering active FAT
#define FATMIRROR 0x80 // FAT is mirrored (like it always was)
unsigned short bpbFSVers; // filesystem version
#define FSVERS 0 // currently only 0 is understood
unsigned long bpbRootClust; // start cluster for root directory
unsigned short bpbFSInfo; // filesystem info structure sector
unsigned short bpbBackup; // backup boot sector
// There is a 12 byte filler here, but we ignore it
};


// ***************************************************************
// * byte versions of the above structs *
// ***************************************************************

// BIOS Parameter Block (BPB) for DOS 3.3
struct byte_bpb33 {
unsigned char bpbBytesPerSec[2]; // bytes per sector
unsigned char bpbSecPerClust; // sectors per cluster
unsigned char bpbResSectors[2]; // number of reserved sectors
unsigned char bpbFATs; // number of FATs
unsigned char bpbRootDirEnts[2]; // number of root directory entries
unsigned char bpbSectors[2]; // total number of sectors
unsigned char bpbMedia; // media descriptor
unsigned char bpbFATsecs[2]; // number of sectors per FAT
unsigned char bpbSecPerTrack[2]; // sectors per track
unsigned char bpbHeads[2]; // number of heads
unsigned char bpbHiddenSecs[2]; // number of hidden sectors
};

// BPB for DOS 5.0
// The difference is bpbHiddenSecs is a short for DOS 3.3,
// and bpbHugeSectors is not in the 3.3 bpb.
struct byte_bpb50 {
unsigned char bpbBytesPerSec[2]; // bytes per sector
unsigned char bpbSecPerClust; // sectors per cluster
unsigned char bpbResSectors[2]; // number of reserved sectors
unsigned char bpbFATs; // number of FATs
unsigned char bpbRootDirEnts[2]; // number of root directory entries
unsigned char bpbSectors[2]; // total number of sectors
unsigned char bpbMedia; // media descriptor
unsigned char bpbFATsecs[2]; // number of sectors per FAT
unsigned char bpbSecPerTrack[2]; // sectors per track
unsigned char bpbHeads[2]; // number of heads
unsigned char bpbHiddenSecs[4]; // number of hidden sectors
unsigned char bpbHugeSectors[4]; // # of sectors if bpbSectors == 0
};

// BPB for DOS 7.10 (FAT32).
// This one has a few extensions to bpb50.
struct byte_bpb710 {
unsigned char bpbBytesPerSec[2]; // bytes per sector
unsigned char bpbSecPerClust; // sectors per cluster
unsigned char bpbResSectors[2]; // number of reserved sectors
unsigned char bpbFATs; // number of FATs
unsigned char bpbRootDirEnts[2]; // number of root directory entries
unsigned char bpbSectors[2]; // total number of sectors
unsigned char bpbMedia; // media descriptor
unsigned char bpbFATsecs[2]; // number of sectors per FAT
unsigned char bpbSecPerTrack[2]; // sectors per track
unsigned char bpbHeads[2]; // number of heads
unsigned char bpbHiddenSecs[4]; // # of hidden sectors
unsigned char bpbHugeSectors[4]; // # of sectors if bpbSectors == 0
unsigned char bpbBigFATsecs[4]; // like bpbFATsecs for FAT32
unsigned char bpbExtFlags[2]; // extended flags:
unsigned char bpbFSVers[2]; // filesystem version
unsigned char bpbRootClust[4]; // start cluster for root directory
unsigned char bpbFSInfo[2]; // filesystem info structure sector
unsigned char bpbBackup[2]; // backup boot sector
// There is a 12 byte filler here, but we ignore it
};

// FAT32 FSInfo block.
struct fsinfo {
unsigned char fsisig1[4];
unsigned char fsifill1[480];
unsigned char fsisig2[4];
unsigned char fsinfree[4];
unsigned char fsinxtfree[4];
unsigned char fsifill2[12];
unsigned char fsisig3[4];
unsigned char fsifill3[508];
unsigned char fsisig4[4];
};


// Structure of a dos directory entry.
struct direntry {
unsigned char 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
unsigned char deExtension[3]; // extension, blank filled
unsigned char deAttributes; // file attributes
#define ATTR_NORMAL 0x00 // normal file
#define ATTR_READONLY 0x01 // file is readonly
#define ATTR_HIDDEN 0x02 // file is hidden
#define ATTR_SYSTEM 0x04 // file is a system file
#define ATTR_VOLUME 0x08 // entry is a volume label
#define ATTR_LONG_FILENAME 0x0F // this is a long filename entry
#define ATTR_DIRECTORY 0x10 // entry is a directory name
#define ATTR_ARCHIVE 0x20 // file is new or modified
unsigned char 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
unsigned char deCHundredth; // hundredth of seconds in CTime
unsigned char deCTime[2]; // create time
unsigned char deCDate[2]; // create date
unsigned char deADate[2]; // access date
unsigned short deHighClust; // high bytes of cluster number
unsigned char deMTime[2]; // last update time
unsigned char deMDate[2]; // last update date
unsigned short deStartCluster; // starting cluster of file
unsigned long deFileSize; // size of file in bytes
};

// number of directory entries in one sector
#define DIRENTRIES_PER_SECTOR 0x10

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

#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


#define FLAGS_ATRMEDIUMSIZE 0x80
#define FLAGS_XEXLOADER 0x40
#define FLAGS_ATRDOUBLESECTORS 0x20
#define FLAGS_XFDTYPE 0x10
#define FLAGS_READONLY 0x08
#define FLAGS_WRITEERROR 0x04
#define FLAGS_DRIVEON 0x01

// Stuctures
typedef struct //2+2+2+2+2+4+1=15
{
unsigned short start_cluster; //< file starting cluster
unsigned short dir_cluster;
unsigned short current_cluster;
unsigned short ncluster;
unsigned short file_index; //< file index
unsigned long size; //< file size
unsigned char flags; //< file flags
}virtual_disk_t;

struct FileInfoStruct
{
unsigned char Attr; //< file attr for last file accessed
unsigned short Date; //< last update date
unsigned short Time; //< last update time
unsigned char percomstate; //=0 default, 1=percomwrite ok (single sectors), 2=percomwrite ok (double sectors), 3=percomwrite bad
//
virtual_disk_t vDisk;
};

struct GlobalSystemValues //4+4+2+2+1=13 bytes
{
unsigned long FirstFATSector;
unsigned long FirstDataSector;
unsigned short RootDirSectors;
unsigned short BytesPerSector;
unsigned char SectorsPerCluster;
};

#define FirstFATSector GS.FirstFATSector
#define FirstDataSector GS.FirstDataSector
#define RootDirSectors GS.RootDirSectors
#define BytesPerSector GS.BytesPerSector
#define SectorsPerCluster GS.SectorsPerCluster


unsigned char fatInit();
unsigned long fatClustToSect(unsigned short clust);
unsigned char fatChangeDirectory(unsigned short entry);
unsigned char fatGetDirEntry(unsigned short entry, unsigned char use_long_names);
unsigned short nextCluster(unsigned short cluster);

#endif