fat.h

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/*
 *  FreeLoader
 *  Copyright (C) 1998-2003  Brian Palmer  <brianp@sginet.com>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
 
#pragma once
 
#include <pshpack1.h>
typedef struct _FAT_BOOTSECTOR
{
    UCHAR        JumpBoot[3];                // Jump instruction to boot code
    CHAR        OemName[8];                    // "MSWIN4.1" for MS formatted volumes
    USHORT        BytesPerSector;                // Bytes per sector
    UCHAR        SectorsPerCluster;            // Number of sectors in a cluster
    USHORT        ReservedSectors;            // Reserved sectors, usually 1 (the bootsector)
    UCHAR        NumberOfFats;                // Number of FAT tables
    USHORT        RootDirEntries;                // Number of root directory entries (fat12/16)
    USHORT        TotalSectors;                // Number of total sectors on the drive, 16-bit
    UCHAR        MediaDescriptor;            // Media descriptor byte
    USHORT        SectorsPerFat;                // Sectors per FAT table (fat12/16)
    USHORT        SectorsPerTrack;            // Number of sectors in a track
    USHORT        NumberOfHeads;                // Number of heads on the disk
    ULONG        HiddenSectors;                // Hidden sectors (sectors before the partition start like the partition table)
    ULONG        TotalSectorsBig;            // This field is the new 32-bit total count of sectors on the volume
    UCHAR        DriveNumber;                // Int 0x13 drive number (e.g. 0x80)
    UCHAR        Reserved1;                    // Reserved (used by Windows NT). Code that formats FAT volumes should always set this byte to 0.
    UCHAR        BootSignature;                // Extended boot signature (0x29). This is a signature byte that indicates that the following three fields in the boot sector are present.
    ULONG        VolumeSerialNumber;            // Volume serial number
    CHAR        VolumeLabel[11];            // Volume label. This field matches the 11-byte volume label recorded in the root directory
    CHAR        FileSystemType[8];            // One of the strings "FAT12   ", "FAT16   ", or "FAT     "
 
    UCHAR        BootCodeAndData[448];        // The remainder of the boot sector
 
    USHORT        BootSectorMagic;            // 0xAA55
 
} FAT_BOOTSECTOR, *PFAT_BOOTSECTOR;
 
typedef struct _FAT32_BOOTSECTOR
{
    UCHAR        JumpBoot[3];                // Jump instruction to boot code
    CHAR        OemName[8];                    // "MSWIN4.1" for MS formatted volumes
    USHORT        BytesPerSector;                // Bytes per sector
    UCHAR        SectorsPerCluster;            // Number of sectors in a cluster
    USHORT        ReservedSectors;            // Reserved sectors, usually 1 (the bootsector)
    UCHAR        NumberOfFats;                // Number of FAT tables
    USHORT        RootDirEntries;                // Number of root directory entries (fat12/16)
    USHORT        TotalSectors;                // Number of total sectors on the drive, 16-bit
    UCHAR        MediaDescriptor;            // Media descriptor byte
    USHORT        SectorsPerFat;                // Sectors per FAT table (fat12/16)
    USHORT        SectorsPerTrack;            // Number of sectors in a track
    USHORT        NumberOfHeads;                // Number of heads on the disk
    ULONG        HiddenSectors;                // Hidden sectors (sectors before the partition start like the partition table)
    ULONG        TotalSectorsBig;            // This field is the new 32-bit total count of sectors on the volume
    ULONG        SectorsPerFatBig;            // This field is the FAT32 32-bit count of sectors occupied by ONE FAT. BPB_FATSz16 must be 0
    USHORT        ExtendedFlags;                // Extended flags (fat32)
    USHORT        FileSystemVersion;            // File system version (fat32)
    ULONG        RootDirStartCluster;        // Starting cluster of the root directory (fat32)
    USHORT        FsInfo;                        // Sector number of FSINFO structure in the reserved area of the FAT32 volume. Usually 1.
    USHORT        BackupBootSector;            // If non-zero, indicates the sector number in the reserved area of the volume of a copy of the boot record. Usually 6.
    UCHAR        Reserved[12];                // Reserved for future expansion
    UCHAR        DriveNumber;                // Int 0x13 drive number (e.g. 0x80)
    UCHAR        Reserved1;                    // Reserved (used by Windows NT). Code that formats FAT volumes should always set this byte to 0.
    UCHAR        BootSignature;                // Extended boot signature (0x29). This is a signature byte that indicates that the following three fields in the boot sector are present.
    ULONG        VolumeSerialNumber;            // Volume serial number
    CHAR        VolumeLabel[11];            // Volume label. This field matches the 11-byte volume label recorded in the root directory
    CHAR        FileSystemType[8];            // Always set to the string "FAT32   "
 
    UCHAR        BootCodeAndData[420];        // The remainder of the boot sector
 
    USHORT        BootSectorMagic;            // 0xAA55
 
} FAT32_BOOTSECTOR, *PFAT32_BOOTSECTOR;
 
typedef struct _FATX_BOOTSECTOR
{
    CHAR        FileSystemType[4];            /* String "FATX" */
    ULONG        VolumeSerialNumber;            /* Volume serial number */
    ULONG        SectorsPerCluster;            /* Number of sectors in a cluster */
    USHORT        NumberOfFats;                /* Number of FAT tables */
    ULONG        Unknown;                /* Always 0? */
    UCHAR        Unused[494];                /* Actually size should be 4078 (boot block is 4096 bytes) */
 
} FATX_BOOTSECTOR, *PFATX_BOOTSECTOR;
 
/*
 * Structure of MSDOS directory entry
 */
typedef struct //_DIRENTRY
{
    CHAR    FileName[11];    /* Filename + extension */
    UCHAR    Attr;        /* File attributes */
    UCHAR    ReservedNT;    /* Reserved for use by Windows NT */
    UCHAR    TimeInTenths;    /* Millisecond stamp at file creation */
    USHORT    CreateTime;    /* Time file was created */
    USHORT    CreateDate;    /* Date file was created */
    USHORT    LastAccessDate;    /* Date file was last accessed */
    USHORT    ClusterHigh;    /* High word of this entry's start cluster */
    USHORT    Time;        /* Time last modified */
    USHORT    Date;        /* Date last modified */
    USHORT    ClusterLow;    /* First cluster number low word */
    ULONG    Size;        /* File size */
} DIRENTRY, * PDIRENTRY;
 
typedef struct
{
    UCHAR    SequenceNumber;        /* Sequence number for slot */
    WCHAR    Name0_4[5];        /* First 5 characters in name */
    UCHAR    EntryAttributes;    /* Attribute byte */
    UCHAR    Reserved;        /* Always 0 */
    UCHAR    AliasChecksum;        /* Checksum for 8.3 alias */
    WCHAR    Name5_10[6];        /* 6 more characters in name */
    USHORT    StartCluster;        /* Starting cluster number */
    WCHAR    Name11_12[2];        /* Last 2 characters in name */
} LFN_DIRENTRY, * PLFN_DIRENTRY;
 
typedef struct
{
    UCHAR    FileNameSize;    /* Size of filename (max 42) */
    UCHAR    Attr;        /* File attributes */
    CHAR    FileName[42];    /* Filename in ASCII, padded with 0xff (not zero-terminated) */
    ULONG    StartCluster;    /* Starting cluster number */
    ULONG    Size;        /* File size */
    USHORT    Time;        /* Time last modified */
    USHORT    Date;        /* Date last modified */
    USHORT    CreateTime;    /* Time file was created */
    USHORT    CreateDate;    /* Date file was created */
    USHORT    LastAccessTime;    /* Time file was last accessed */
    USHORT    LastAccessDate;    /* Date file was last accessed */
} FATX_DIRENTRY, * PFATX_DIRENTRY;
#include <poppack.h>
 
#define FAT_ATTR_NORMAL     0x00
#define FAT_ATTR_READONLY   0x01
#define FAT_ATTR_HIDDEN     0x02
#define FAT_ATTR_SYSTEM     0x04
#define FAT_ATTR_VOLUMENAME 0x08
#define FAT_ATTR_DIRECTORY  0x10
#define FAT_ATTR_ARCHIVE    0x20
#define FAT_ATTR_LONG_NAME  (FAT_ATTR_READONLY | FAT_ATTR_HIDDEN | FAT_ATTR_SYSTEM | FAT_ATTR_VOLUMENAME)
 
#define FAT12   1
#define FAT16   2
#define FAT32   3
#define FATX16  4
#define FATX32  5
 
#define ISFATX(FT) ((FT) == FATX16 || (FT) == FATX32)
 
typedef struct _FAT_VOLUME_INFO *PFAT_VOLUME_INFO;
 
typedef struct _FAT_FILE_INFO
{
    PFAT_VOLUME_INFO Volume;
    ULONG FileSize;         // File size
    ULONG FilePointer;      // File pointer
    ULONG CurrentCluster;   // Cluster for file pointer
    ULONG StartCluster;     // File first cluster
    ULONG FileNameLength;
    UCHAR Attributes;
    CHAR FileName[RTL_FIELD_SIZE(FILEINFORMATION, FileName)];
} FAT_FILE_INFO, *PFAT_FILE_INFO;
 
ULONGLONG
FatGetVolumeSize(
    _In_ ULONG DeviceId);
 
const DEVVTBL* FatMount(ULONG DeviceId);