/*! \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