fat32disk.h

#ifndef FATFILESYSTEM_H
#define FATFILESYSTEM_H

#include <stdlib.h>
#include <stdint.h>

#pragma pack(push,1)
typedef struct BootEntry {
  unsigned char  BS_jmpBoot[3];     // Assembly instruction to jump to boot code
  unsigned char  BS_OEMName[8];     // OEM Name in ASCII
  unsigned short BPB_BytsPerSec;    // Bytes per sector. Allowed values include 512, 1024, 2048, and 4096
  unsigned char  BPB_SecPerClus;    // Sectors per cluster (data unit). Allowed values are powers of 2, but the cluster size must be 32KB or smaller
  unsigned short BPB_RsvdSecCnt;    // Size in sectors of the reserved area
  unsigned char  BPB_NumFATs;       // Number of FATs
  unsigned short BPB_RootEntCnt;    // Maximum number of files in the root directory for FAT12 and FAT16. This is 0 for FAT32
  unsigned short BPB_TotSec16;      // 16-bit value of number of sectors in file system
  unsigned char  BPB_Media;         // Media type
  unsigned short BPB_FATSz16;       // 16-bit size in sectors of each FAT for FAT12 and FAT16. For FAT32, this field is 0
  unsigned short BPB_SecPerTrk;     // Sectors per track of storage device
  unsigned short BPB_NumHeads;      // Number of heads in storage device
  unsigned int   BPB_HiddSec;       // Number of sectors before the start of partition
  unsigned int   BPB_TotSec32;      // 32-bit value of number of sectors in file system. Either this value or the 16-bit value above must be 0
  unsigned int   BPB_FATSz32;       // 32-bit size in sectors of one FAT
  unsigned short BPB_ExtFlags;      // A flag for FAT
  unsigned short BPB_FSVer;         // The major and minor version number
  unsigned int   BPB_RootClus;      // Cluster where the root directory can be found
  unsigned short BPB_FSInfo;        // Sector where FSINFO structure can be found
  unsigned short BPB_BkBootSec;     // Sector where backup copy of boot sector is located
  unsigned char  BPB_Reserved[12];  // Reserved
  unsigned char  BS_DrvNum;         // BIOS INT13h drive number
  unsigned char  BS_Reserved1;      // Not used
  unsigned char  BS_BootSig;        // Extended boot signature to identify if the next three values are valid
  unsigned int   BS_VolID;          // Volume serial number
  unsigned char  BS_VolLab[11];     // Volume label in ASCII. User defines when creating the file system
  unsigned char  BS_FilSysType[8];  // File system type label in ASCII
} BootEntry;
#pragma pack(pop)

#pragma pack(push,1)
typedef struct DirEntry {
  unsigned char  DIR_Name[11];      // File name
  unsigned char  DIR_Attr;          // File attributes
  unsigned char  DIR_NTRes;         // Reserved
  unsigned char  DIR_CrtTimeTenth;  // Created time (tenths of second)
  unsigned short DIR_CrtTime;       // Created time (hours, minutes, seconds)
  unsigned short DIR_CrtDate;       // Created day
  unsigned short DIR_LstAccDate;    // Accessed day
  unsigned short DIR_FstClusHI;     // High 2 bytes of the first cluster address
  unsigned short DIR_WrtTime;       // Written time (hours, minutes, seconds
  unsigned short DIR_WrtDate;       // Written day
  unsigned short DIR_FstClusLO;     // Low 2 bytes of the first cluster address
  unsigned int   DIR_FileSize;      // File size in bytes. (0 for directories)
} DirEntry;
#pragma pack(pop)

unsigned int getFileDirectory(const char *diskName);
BootEntry* readFileSystem(int fd);
void showDiskInformation(BootEntry* disk);
void showUsage();

#endif