FatStructs.h

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/* Arduino SdFat Library
 * Copyright (C) 2009 by William Greiman
 *
 * This file is part of the Arduino SdFat Library
 *
 * This Library 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 3 of the License, or
 * (at your option) any later version.
 *
 * This Library 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 the Arduino SdFat Library.  If not, see
 * <http://www.gnu.org/licenses/>.
 */
#ifndef FatStructs_h
#define FatStructs_h

/*
 * mostly from Microsoft document fatgen103.doc
 * http://www.microsoft.com/whdc/system/platform/firmware/fatgen.mspx
 */
//------------------------------------------------------------------------------
uint8_t const BOOTSIG0 = 0X55;
uint8_t const BOOTSIG1 = 0XAA;
//------------------------------------------------------------------------------
struct partitionTable {
  uint8_t  boot;
  uint8_t  beginHead;
  unsigned beginSector : 6;
  unsigned beginCylinderHigh : 2;
  uint8_t  beginCylinderLow;
  uint8_t  type;
  uint8_t  endHead;
  unsigned endSector : 6;
  unsigned endCylinderHigh : 2;
  uint8_t  endCylinderLow;
  uint32_t firstSector;
  uint32_t totalSectors;
} __attribute__((packed));
typedef struct partitionTable part_t;
//------------------------------------------------------------------------------
struct masterBootRecord {
  uint8_t  codeArea[440];
  uint32_t diskSignature;
  uint16_t usuallyZero;
  part_t   part[4];
  uint8_t  mbrSig0;
  uint8_t  mbrSig1;
} __attribute__((packed));
typedef struct masterBootRecord mbr_t;
//------------------------------------------------------------------------------
struct biosParmBlock {
  uint16_t bytesPerSector;
  uint8_t  sectorsPerCluster;
  uint16_t reservedSectorCount;
  uint8_t  fatCount;
  uint16_t rootDirEntryCount;
  uint16_t totalSectors16;
  uint8_t  mediaType;
  uint16_t sectorsPerFat16;
  uint16_t sectorsPerTrtack;
  uint16_t headCount;
  uint32_t hidddenSectors;
  uint32_t totalSectors32;
  uint32_t sectorsPerFat32;
  uint16_t fat32Flags;
  uint16_t fat32Version;
  uint32_t fat32RootCluster;
  uint16_t fat32FSInfo;
  uint16_t fat32BackBootBlock;
  uint8_t  fat32Reserved[12];
} __attribute__((packed));
typedef struct biosParmBlock bpb_t;
//------------------------------------------------------------------------------
struct fat32BootSector {
  uint8_t  jmpToBootCode[3];
  char     oemName[8];
  bpb_t    bpb;
  uint8_t  driveNumber;
  uint8_t  reserved1;
  uint8_t  bootSignature;
  uint32_t volumeSerialNumber;
  char     volumeLabel[11];
  char     fileSystemType[8];
  uint8_t  bootCode[420];
  uint8_t  bootSectorSig0;
  uint8_t  bootSectorSig1;
} __attribute__((packed));
//------------------------------------------------------------------------------
// End Of Chain values for FAT entries
uint16_t const FAT16EOC = 0XFFFF;
uint16_t const FAT16EOC_MIN = 0XFFF8;
uint32_t const FAT32EOC = 0X0FFFFFFF;
uint32_t const FAT32EOC_MIN = 0X0FFFFFF8;
uint32_t const FAT32MASK = 0X0FFFFFFF;

typedef struct fat32BootSector fbs_t;
//------------------------------------------------------------------------------
struct directoryEntry {
  uint8_t  name[11];
  uint8_t  attributes;
  uint8_t  reservedNT;
  uint8_t  creationTimeTenths;
  uint16_t creationTime;
  uint16_t creationDate;
  uint16_t lastAccessDate;
  uint16_t firstClusterHigh;
  uint16_t lastWriteTime;
  uint16_t lastWriteDate;
  uint16_t firstClusterLow;
  uint32_t fileSize;
} __attribute__((packed));
//------------------------------------------------------------------------------
// Definitions for directory entries
//
typedef struct directoryEntry dir_t;
uint8_t const DIR_NAME_0XE5 = 0X05;
uint8_t const DIR_NAME_DELETED = 0XE5;
uint8_t const DIR_NAME_FREE = 0X00;
uint8_t const DIR_ATT_READ_ONLY = 0X01;
uint8_t const DIR_ATT_HIDDEN = 0X02;
uint8_t const DIR_ATT_SYSTEM = 0X04;
uint8_t const DIR_ATT_VOLUME_ID = 0X08;
uint8_t const DIR_ATT_DIRECTORY = 0X10;
uint8_t const DIR_ATT_ARCHIVE = 0X20;
uint8_t const DIR_ATT_LONG_NAME = 0X0F;
uint8_t const DIR_ATT_LONG_NAME_MASK = 0X3F;
uint8_t const DIR_ATT_DEFINED_BITS = 0X3F;
static inline uint8_t DIR_IS_LONG_NAME(const dir_t* dir) {
  return (dir->attributes & DIR_ATT_LONG_NAME_MASK) == DIR_ATT_LONG_NAME;
}
uint8_t const DIR_ATT_FILE_TYPE_MASK = (DIR_ATT_VOLUME_ID | DIR_ATT_DIRECTORY);
static inline uint8_t DIR_IS_FILE(const dir_t* dir) {
  return (dir->attributes & DIR_ATT_FILE_TYPE_MASK) == 0;
}
static inline uint8_t DIR_IS_SUBDIR(const dir_t* dir) {
  return (dir->attributes & DIR_ATT_FILE_TYPE_MASK) == DIR_ATT_DIRECTORY;
}
static inline uint8_t DIR_IS_FILE_OR_SUBDIR(const dir_t* dir) {
  return (dir->attributes & DIR_ATT_VOLUME_ID) == 0;
}
#endif  // FatStructs_h