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/*! \file fat.h \brief FAT16/32 file system driver. */
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//*****************************************************************************
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//
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// File Name : 'fat.h'
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// Title : FAT16/32 file system driver
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// Author : Pascal Stang
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// Date : 11/07/2000
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// Revised : 12/12/2000
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// Version : 0.3
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// Target MCU : ATmega103 (should work for Atmel AVR Series)
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// Editor Tabs : 4
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//
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// NOTE: This code is currently below version 1.0, and therefore is considered
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// to be lacking in some functionality or documentation, or may not be fully
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// tested. Nonetheless, you can expect most functions to work.
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//
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/// \ingroup general
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/// \defgroup fat FAT16/32 File System Interface (fat.c)
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/// \code #include "fat.h" \endcode
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/// \par Overview
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/// This FAT16/32 interface allows you to detect and mount FAT16/32
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/// partitions, browse directories and files, and read file data.
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/// The interface is designed to operate with the avrlib IDE/ATA driver.
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/// Reading FAT efficiently requires at least 512+ bytes of RAM so this
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/// interface may not be suitable for processors with less than 1K of RAM.
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/// This interface will properly follow a file's cluster chain so files
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/// need not be defragmented.
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///
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/// \note This code is based in part on work done by Jesper Hansen for his
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/// excellent YAMPP MP3 player project.
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//
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// ----------------------------------------------------------------------------
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// 17.8.2008
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// Bob!k & Raster, C.P.U.
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// Original code was modified especially for the SDrive device.
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// Some parts of code have been added, removed, rewrited or optimized due to
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// lack of MCU AVR Atmega8 memory.
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// ----------------------------------------------------------------------------
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//
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// This code is distributed under the GNU Public License
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// which can be found at http://www.gnu.org/licenses/gpl.txt
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//
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//*****************************************************************************
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#ifndef FAT_H
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#define FAT_H
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#define FALSE 0
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#define TRUE -1
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#define DRIVE0 1
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// Some useful cluster numbers
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#define MSDOSFSROOT 0 // cluster 0 means the root dir
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#define CLUST_FREE 0 // cluster 0 also means a free cluster
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#define MSDOSFSFREE CLUST_FREE
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#define CLUST_FIRST 2 // first legal cluster number
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#define CLUST_RSRVD 0xfffffff6 // reserved cluster range
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#define CLUST_BAD 0xfffffff7 // a cluster with a defect
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#define CLUST_EOFS 0xfffffff8 // start of eof cluster range
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#define CLUST_EOFE 0xffffffff // end of eof cluster range
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#define FAT12_MASK 0x00000fff // mask for 12 bit cluster numbers
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#define FAT16_MASK 0x0000ffff // mask for 16 bit cluster numbers
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#define FAT32_MASK 0x0fffffff // mask for FAT32 cluster numbers
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// Partition Type used in the partition record
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#define PART_TYPE_UNKNOWN 0x00
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#define PART_TYPE_FAT12 0x01
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#define PART_TYPE_XENIX 0x02
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#define PART_TYPE_DOSFAT16 0x04
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#define PART_TYPE_EXTDOS 0x05
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#define PART_TYPE_FAT16 0x06
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#define PART_TYPE_NTFS 0x07
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#define PART_TYPE_FAT32 0x0B
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#define PART_TYPE_FAT32LBA 0x0C
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#define PART_TYPE_FAT16LBA 0x0E
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#define PART_TYPE_EXTDOSLBA 0x0F
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#define PART_TYPE_ONTRACK 0x33
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#define PART_TYPE_NOVELL 0x40
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#define PART_TYPE_PCIX 0x4B
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#define PART_TYPE_PHOENIXSAVE 0xA0
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#define PART_TYPE_CPM 0xDB
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#define PART_TYPE_DBFS 0xE0
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#define PART_TYPE_BBT 0xFF
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struct partrecord // length 16 bytes
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{
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unsigned char prIsActive; // 0x80 indicates active partition
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unsigned char prStartHead; // starting head for partition
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unsigned short prStartCylSect; // starting cylinder and sector
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unsigned char prPartType; // partition type (see above)
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unsigned char prEndHead; // ending head for this partition
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unsigned short prEndCylSect; // ending cylinder and sector
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unsigned long prStartLBA; // first LBA sector for this partition
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unsigned long prSize; // size of this partition (bytes or sectors ?)
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};
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struct partsector
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{
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unsigned char psPartCode[512-64-2]; // pad so struct is 512b
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unsigned char psPart[64]; // four partition records (64 bytes)
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unsigned char psBootSectSig0; // two signature bytes (2 bytes)
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unsigned char psBootSectSig1;
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#define BOOTSIG0 0x55
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#define BOOTSIG1 0xaa
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};
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// Format of a boot sector. This is the first sector on a DOS floppy disk
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// or the first sector of a partition on a hard disk. But, it is not the
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// first sector of a partitioned hard disk.
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struct bootsector33 {
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unsigned char bsJump[3]; // jump inst E9xxxx or EBxx90
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unsigned char bsOemName[8]; // OEM name and version
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unsigned char bsBPB[19]; // BIOS parameter block
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unsigned char bsDriveNumber; // drive number (0x80)
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unsigned char bsBootCode[479]; // pad so struct is 512b
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unsigned char bsBootSectSig0; // boot sector signature byte 0x55
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unsigned char bsBootSectSig1; // boot sector signature byte 0xAA
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#define BOOTSIG0 0x55
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#define BOOTSIG1 0xaa
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};
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struct extboot {
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unsigned char exDriveNumber; // drive number (0x80)
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unsigned char exReserved1; // reserved
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unsigned char exBootSignature; // ext. boot signature (0x29)
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#define EXBOOTSIG 0x29
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unsigned char exVolumeID[4]; // volume ID number
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unsigned char exVolumeLabel[11]; // volume label
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unsigned char exFileSysType[8]; // fs type (FAT12 or FAT16)
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};
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struct bootsector50 {
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unsigned char bsJump[3]; // jump inst E9xxxx or EBxx90
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unsigned char bsOemName[8]; // OEM name and version
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unsigned char bsBPB[25]; // BIOS parameter block
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unsigned char bsExt[26]; // Bootsector Extension
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unsigned char bsBootCode[448]; // pad so structure is 512b
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unsigned char bsBootSectSig0; // boot sector signature byte 0x55
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unsigned char bsBootSectSig1; // boot sector signature byte 0xAA
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#define BOOTSIG0 0x55
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#define BOOTSIG1 0xaa
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};
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struct bootsector710 {
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unsigned char bsJump[3]; // jump inst E9xxxx or EBxx90
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unsigned char bsOEMName[8]; // OEM name and version
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unsigned char bsBPB[53]; // BIOS parameter block
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unsigned char bsExt[26]; // Bootsector Extension
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unsigned char bsBootCode[418]; // pad so structure is 512b
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unsigned char bsBootSectSig2; // 2 & 3 are only defined for FAT32?
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unsigned char bsBootSectSig3;
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unsigned char bsBootSectSig0; // boot sector signature byte 0x55
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unsigned char bsBootSectSig1; // boot sector signature byte 0xAA
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#define BOOTSIG0 0x55
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#define BOOTSIG1 0xaa
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#define BOOTSIG2 0
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#define BOOTSIG3 0
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};
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/***************************************************************/
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/***************************************************************/
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// BIOS Parameter Block (BPB) for DOS 3.3
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struct bpb33 {
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unsigned short bpbBytesPerSec; // bytes per sector
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unsigned char bpbSecPerClust; // sectors per cluster
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unsigned short bpbResSectors; // number of reserved sectors
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unsigned char bpbFATs; // number of FATs
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unsigned short bpbRootDirEnts; // number of root directory entries
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unsigned short bpbSectors; // total number of sectors
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unsigned char bpbMedia; // media descriptor
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unsigned short bpbFATsecs; // number of sectors per FAT
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unsigned short bpbSecPerTrack; // sectors per track
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unsigned short bpbHeads; // number of heads
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unsigned short bpbHiddenSecs; // number of hidden sectors
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};
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// BPB for DOS 5.0
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// The difference is bpbHiddenSecs is a short for DOS 3.3,
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// and bpbHugeSectors is not present in the DOS 3.3 bpb.
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struct bpb50 {
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unsigned short bpbBytesPerSec; // bytes per sector
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unsigned char bpbSecPerClust; // sectors per cluster
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unsigned short bpbResSectors; // number of reserved sectors
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unsigned char bpbFATs; // number of FATs
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unsigned short bpbRootDirEnts; // number of root directory entries
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unsigned short bpbSectors; // total number of sectors
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unsigned char bpbMedia; // media descriptor
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unsigned short bpbFATsecs; // number of sectors per FAT
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unsigned short bpbSecPerTrack; // sectors per track
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unsigned short bpbHeads; // number of heads
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unsigned long bpbHiddenSecs; // # of hidden sectors
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// 3.3 compat ends here
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unsigned long bpbHugeSectors; // # of sectors if bpbSectors == 0
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};
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// BPB for DOS 7.10 (FAT32)
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// This one has a few extensions to bpb50.
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struct bpb710 {
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unsigned short bpbBytesPerSec; // bytes per sector
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unsigned char bpbSecPerClust; // sectors per cluster
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unsigned short bpbResSectors; // number of reserved sectors
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unsigned char bpbFATs; // number of FATs
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unsigned short bpbRootDirEnts; // number of root directory entries
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unsigned short bpbSectors; // total number of sectors
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unsigned char bpbMedia; // media descriptor
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unsigned short bpbFATsecs; // number of sectors per FAT
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unsigned short bpbSecPerTrack; // sectors per track
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unsigned short bpbHeads; // number of heads
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unsigned long bpbHiddenSecs; // # of hidden sectors
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// 3.3 compat ends here
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unsigned long bpbHugeSectors; // # of sectors if bpbSectors == 0
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// 5.0 compat ends here
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unsigned long bpbBigFATsecs;// like bpbFATsecs for FAT32
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unsigned short bpbExtFlags; // extended flags:
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#define FATNUM 0xf // mask for numbering active FAT
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#define FATMIRROR 0x80 // FAT is mirrored (like it always was)
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unsigned short bpbFSVers; // filesystem version
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#define FSVERS 0 // currently only 0 is understood
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unsigned long bpbRootClust; // start cluster for root directory
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unsigned short bpbFSInfo; // filesystem info structure sector
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unsigned short bpbBackup; // backup boot sector
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// There is a 12 byte filler here, but we ignore it
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};
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// ***************************************************************
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// * byte versions of the above structs *
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// ***************************************************************
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// BIOS Parameter Block (BPB) for DOS 3.3
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struct byte_bpb33 {
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unsigned char bpbBytesPerSec[2]; // bytes per sector
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unsigned char bpbSecPerClust; // sectors per cluster
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unsigned char bpbResSectors[2]; // number of reserved sectors
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unsigned char bpbFATs; // number of FATs
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unsigned char bpbRootDirEnts[2]; // number of root directory entries
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unsigned char bpbSectors[2]; // total number of sectors
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unsigned char bpbMedia; // media descriptor
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unsigned char bpbFATsecs[2]; // number of sectors per FAT
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unsigned char bpbSecPerTrack[2]; // sectors per track
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unsigned char bpbHeads[2]; // number of heads
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unsigned char bpbHiddenSecs[2]; // number of hidden sectors
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};
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// BPB for DOS 5.0
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// The difference is bpbHiddenSecs is a short for DOS 3.3,
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// and bpbHugeSectors is not in the 3.3 bpb.
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struct byte_bpb50 {
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unsigned char bpbBytesPerSec[2]; // bytes per sector
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unsigned char bpbSecPerClust; // sectors per cluster
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unsigned char bpbResSectors[2]; // number of reserved sectors
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unsigned char bpbFATs; // number of FATs
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unsigned char bpbRootDirEnts[2]; // number of root directory entries
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unsigned char bpbSectors[2]; // total number of sectors
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unsigned char bpbMedia; // media descriptor
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unsigned char bpbFATsecs[2]; // number of sectors per FAT
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unsigned char bpbSecPerTrack[2]; // sectors per track
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unsigned char bpbHeads[2]; // number of heads
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unsigned char bpbHiddenSecs[4]; // number of hidden sectors
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unsigned char bpbHugeSectors[4]; // # of sectors if bpbSectors == 0
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};
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// BPB for DOS 7.10 (FAT32).
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// This one has a few extensions to bpb50.
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struct byte_bpb710 {
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unsigned char bpbBytesPerSec[2]; // bytes per sector
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unsigned char bpbSecPerClust; // sectors per cluster
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unsigned char bpbResSectors[2]; // number of reserved sectors
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unsigned char bpbFATs; // number of FATs
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unsigned char bpbRootDirEnts[2]; // number of root directory entries
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unsigned char bpbSectors[2]; // total number of sectors
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unsigned char bpbMedia; // media descriptor
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unsigned char bpbFATsecs[2]; // number of sectors per FAT
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unsigned char bpbSecPerTrack[2]; // sectors per track
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unsigned char bpbHeads[2]; // number of heads
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unsigned char bpbHiddenSecs[4]; // # of hidden sectors
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unsigned char bpbHugeSectors[4]; // # of sectors if bpbSectors == 0
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unsigned char bpbBigFATsecs[4]; // like bpbFATsecs for FAT32
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unsigned char bpbExtFlags[2]; // extended flags:
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unsigned char bpbFSVers[2]; // filesystem version
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unsigned char bpbRootClust[4]; // start cluster for root directory
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unsigned char bpbFSInfo[2]; // filesystem info structure sector
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unsigned char bpbBackup[2]; // backup boot sector
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// There is a 12 byte filler here, but we ignore it
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};
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// FAT32 FSInfo block.
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struct fsinfo {
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unsigned char fsisig1[4];
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unsigned char fsifill1[480];
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unsigned char fsisig2[4];
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unsigned char fsinfree[4];
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unsigned char fsinxtfree[4];
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unsigned char fsifill2[12];
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unsigned char fsisig3[4];
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unsigned char fsifill3[508];
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unsigned char fsisig4[4];
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};
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// Structure of a dos directory entry.
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struct direntry {
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unsigned char deName[8]; // filename, blank filled
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#define SLOT_EMPTY 0x00 // slot has never been used
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#define SLOT_E5 0x05 // the real value is 0xE5
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#define SLOT_DELETED 0xE5 // file in this slot deleted
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unsigned char deExtension[3]; // extension, blank filled
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unsigned char deAttributes; // file attributes
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#define ATTR_NORMAL 0x00 // normal file
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#define ATTR_READONLY 0x01 // file is readonly
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#define ATTR_HIDDEN 0x02 // file is hidden
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#define ATTR_SYSTEM 0x04 // file is a system file
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#define ATTR_VOLUME 0x08 // entry is a volume label
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#define ATTR_LONG_FILENAME 0x0F // this is a long filename entry
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#define ATTR_DIRECTORY 0x10 // entry is a directory name
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#define ATTR_ARCHIVE 0x20 // file is new or modified
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unsigned char deLowerCase; // NT VFAT lower case flags (set to zero)
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#define LCASE_BASE 0x08 // filename base in lower case
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#define LCASE_EXT 0x10 // filename extension in lower case
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unsigned char deCHundredth; // hundredth of seconds in CTime
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unsigned char deCTime[2]; // create time
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unsigned char deCDate[2]; // create date
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unsigned char deADate[2]; // access date
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unsigned short deHighClust; // high bytes of cluster number
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unsigned char deMTime[2]; // last update time
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unsigned char deMDate[2]; // last update date
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unsigned short deStartCluster; // starting cluster of file
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unsigned long deFileSize; // size of file in bytes
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};
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// number of directory entries in one sector
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#define DIRENTRIES_PER_SECTOR 0x10
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// Structure of a Win95 long name directory entry
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struct winentry {
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unsigned char weCnt; //
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#define WIN_LAST 0x40
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#define WIN_CNT 0x3f
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unsigned char wePart1[10];
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unsigned char weAttributes;
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#define ATTR_WIN95 0x0f
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unsigned char weReserved1;
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unsigned char weChksum;
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unsigned char wePart2[12];
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unsigned short weReserved2;
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unsigned char wePart3[4];
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};
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#define WIN_ENTRY_CHARS 13 // Number of chars per winentry
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// Maximum filename length in Win95
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// Note: Must be < sizeof(dirent.d_name)
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#define WIN_MAXLEN 255
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// This is the format of the contents of the deTime field in the direntry
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// structure.
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// We don't use bitfields because we don't know how compilers for
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// arbitrary machines will lay them out.
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#define DT_2SECONDS_MASK 0x1F // seconds divided by 2
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#define DT_2SECONDS_SHIFT 0
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#define DT_MINUTES_MASK 0x7E0 // minutes
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#define DT_MINUTES_SHIFT 5
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#define DT_HOURS_MASK 0xF800 // hours
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#define DT_HOURS_SHIFT 11
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// This is the format of the contents of the deDate field in the direntry
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// structure.
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#define DD_DAY_MASK 0x1F // day of month
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#define DD_DAY_SHIFT 0
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#define DD_MONTH_MASK 0x1E0 // month
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#define DD_MONTH_SHIFT 5
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#define DD_YEAR_MASK 0xFE00 // year - 1980
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#define DD_YEAR_SHIFT 9
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#define FLAGS_ATRMEDIUMSIZE 0x80
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#define FLAGS_XEXLOADER 0x40
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#define FLAGS_ATRDOUBLESECTORS 0x20
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#define FLAGS_XFDTYPE 0x10
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#define FLAGS_READONLY 0x08
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#define FLAGS_WRITEERROR 0x04
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#define FLAGS_DRIVEON 0x01
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// Stuctures
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typedef struct //2+2+2+2+2+4+1=15
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{
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unsigned short start_cluster; //< file starting cluster
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unsigned short dir_cluster;
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unsigned short current_cluster;
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unsigned short ncluster;
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unsigned short file_index; //< file index
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unsigned long size; //< file size
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unsigned char flags; //< file flags
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}virtual_disk_t;
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struct FileInfoStruct
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{
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unsigned char Attr; //< file attr for last file accessed
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unsigned short Date; //< last update date
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unsigned short Time; //< last update time
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unsigned char percomstate; //=0 default, 1=percomwrite ok (single sectors), 2=percomwrite ok (double sectors), 3=percomwrite bad
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//
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virtual_disk_t vDisk;
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};
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struct GlobalSystemValues //4+4+2+2+1=13 bytes
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{
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unsigned long FirstFATSector;
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unsigned long FirstDataSector;
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unsigned short RootDirSectors;
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unsigned short BytesPerSector;
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unsigned char SectorsPerCluster;
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};
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#define FirstFATSector GS.FirstFATSector
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#define FirstDataSector GS.FirstDataSector
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#define RootDirSectors GS.RootDirSectors
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#define BytesPerSector GS.BytesPerSector
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#define SectorsPerCluster GS.SectorsPerCluster
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unsigned char fatInit();
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unsigned long fatClustToSect(unsigned short clust);
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unsigned char fatChangeDirectory(unsigned short entry);
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unsigned char fatGetDirEntry(unsigned short entry, unsigned char use_long_names);
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unsigned short nextCluster(unsigned short cluster);
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#endif
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