Quadrotor

/* 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

/**

 * \file

 * FAT file structures

 */

/*

 * mostly from Microsoft document fatgen103.doc

 * http://www.microsoft.com/whdc/system/platform/firmware/fatgen.mspx

 */

//------------------------------------------------------------------------------

/** Value for byte 510 of boot block or MBR */

uint8_t const BOOTSIG0 = 0X55;

/** Value for byte 511 of boot block or MBR */

uint8_t const BOOTSIG1 = 0XAA;

//------------------------------------------------------------------------------

/**

 * \struct partitionTable

 * \brief MBR partition table entry

 *

 * A partition table entry for a MBR formatted storage device.

 * The MBR partition table has four entries.

 */

struct partitionTable {

          /**

           * Boot Indicator . Indicates whether the volume is the active

           * partition.  Legal values include: 0X00. Do not use for booting.

           * 0X80 Active partition.

           */

  uint8_t  boot;

          /**

            * Head part of Cylinder-head-sector address of the first block in

            * the partition. Legal values are 0-255. Only used in old PC BIOS.

            */

  uint8_t  beginHead;

          /**

           * Sector part of Cylinder-head-sector address of the first block in

           * the partition. Legal values are 1-63. Only used in old PC BIOS.

           */

  unsigned beginSector : 6;

           /** High bits cylinder for first block in partition. */

  unsigned beginCylinderHigh : 2;

          /**

           * Combine beginCylinderLow with beginCylinderHigh. Legal values

           * are 0-1023.  Only used in old PC BIOS.

           */

  uint8_t  beginCylinderLow;

          /**

           * Partition type. See defines that begin with PART_TYPE_ for

           * some Microsoft partition types.

           */

  uint8_t  type;

          /**

           * head part of cylinder-head-sector address of the last sector in the

           * partition.  Legal values are 0-255. Only used in old PC BIOS.

           */

  uint8_t  endHead;

          /**

           * Sector part of cylinder-head-sector address of the last sector in

           * the partition.  Legal values are 1-63. Only used in old PC BIOS.

           */

  unsigned endSector : 6;

           /** High bits of end cylinder */

  unsigned endCylinderHigh : 2;

          /**

           * Combine endCylinderLow with endCylinderHigh. Legal values

           * are 0-1023.  Only used in old PC BIOS.

           */

  uint8_t  endCylinderLow;

           /** Logical block address of the first block in the partition. */

  uint32_t firstSector;

           /** Length of the partition, in blocks. */

  uint32_t totalSectors;

};

/** Type name for partitionTable */

typedef struct partitionTable part_t;

//------------------------------------------------------------------------------

/**

 * \struct masterBootRecord

 *

 * \brief Master Boot Record

 *

 * The first block of a storage device that is formatted with a MBR.

 */

struct masterBootRecord {

           /** Code Area for master boot program. */

  uint8_t  codeArea[440];

           /** Optional WindowsNT disk signature. May contain more boot code. */

  uint32_t diskSignature;

           /** Usually zero but may be more boot code. */

  uint16_t usuallyZero;

           /** Partition tables. */

  part_t   part[4];

           /** First MBR signature byte. Must be 0X55 */

  uint8_t  mbrSig0;

           /** Second MBR signature byte. Must be 0XAA */

  uint8_t  mbrSig1;

};

/** Type name for masterBootRecord */

typedef struct masterBootRecord mbr_t;

//------------------------------------------------------------------------------

/** 

 * \struct biosParmBlock

 *

 * \brief BIOS parameter block

 * 

 *  The BIOS parameter block describes the physical layout of a FAT volume.

 */

struct biosParmBlock {

          /**

           * Count of bytes per sector. This value may take on only the

           * following values: 512, 1024, 2048 or 4096

           */

  uint16_t bytesPerSector;

          /**

           * Number of sectors per allocation unit. This value must be a

           * power of 2 that is greater than 0. The legal values are

           * 1, 2, 4, 8, 16, 32, 64, and 128.

           */

  uint8_t  sectorsPerCluster;

          /**

           * Number of sectors before the first FAT.

           * This value must not be zero.

           */

  uint16_t reservedSectorCount;

          /** The count of FAT data structures on the volume. This field should

           *  always contain the value 2 for any FAT volume of any type.

           */

  uint8_t  fatCount;

          /**

          * For FAT12 and FAT16 volumes, this field contains the count of

          * 32-byte directory entries in the root directory. For FAT32 volumes,

          * this field must be set to 0. For FAT12 and FAT16 volumes, this

          * value should always specify a count that when multiplied by 32

          * results in a multiple of bytesPerSector.  FAT16 volumes should

          * use the value 512.

          */

  uint16_t rootDirEntryCount;

          /**

           * This field is the old 16-bit total count of sectors on the volume.

           * This count includes the count of all sectors in all four regions

           * of the volume. This field can be 0; if it is 0, then totalSectors32

           * must be non-zero.  For FAT32 volumes, this field must be 0. For

           * FAT12 and FAT16 volumes, this field contains the sector count, and

           * totalSectors32 is 0 if the total sector count fits

           * (is less than 0x10000).

           */

  uint16_t totalSectors16;

          /**

           * This dates back to the old MS-DOS 1.x media determination and is

           * no longer usually used for anything.  0xF8 is the standard value

           * for fixed (non-removable) media. For removable media, 0xF0 is

           * frequently used. Legal values are 0xF0 or 0xF8-0xFF.

           */

  uint8_t  mediaType;

          /**

           * Count of sectors occupied by one FAT on FAT12/FAT16 volumes.

           * On FAT32 volumes this field must be 0, and sectorsPerFat32

           * contains the FAT size count.

           */

  uint16_t sectorsPerFat16;

           /** Sectors per track for interrupt 0x13. Not used otherwise. */

  uint16_t sectorsPerTrtack;

           /** Number of heads for interrupt 0x13.  Not used otherwise. */

  uint16_t headCount;

          /**

           * Count of hidden sectors preceding the partition that contains this

           * FAT volume. This field is generally only relevant for media

           *  visible on interrupt 0x13.

           */

  uint32_t hidddenSectors;

          /**

           * This field is the new 32-bit total count of sectors on the volume.

           * This count includes the count of all sectors in all four regions

           * of the volume.  This field can be 0; if it is 0, then

           * totalSectors16 must be non-zero.

           */

  uint32_t totalSectors32;

          /**

           * Count of sectors occupied by one FAT on FAT32 volumes.

           */

  uint32_t sectorsPerFat32;

          /**

           * This field is only defined for FAT32 media and does not exist on

           * FAT12 and FAT16 media.

           * Bits 0-3 -- Zero-based number of active FAT.

           *             Only valid if mirroring is disabled.

           * Bits 4-6 -- Reserved.

           * Bit 7        -- 0 means the FAT is mirrored at runtime into all FATs.

                 *        -- 1 means only one FAT is active; it is the one referenced in bits 0-3.

           * Bits 8-15         -- Reserved.

           */

  uint16_t fat32Flags;

          /**

           * FAT32 version. High byte is major revision number.

           * Low byte is minor revision number. Only 0.0 define.

           */

  uint16_t fat32Version;

          /**

           * Cluster number of the first cluster of the root directory for FAT32.

           * This usually 2 but not required to be 2.

           */

  uint32_t fat32RootCluster;

          /**

           * Sector number of FSINFO structure in the reserved area of the

           * FAT32 volume. Usually 1.

           */

  uint16_t fat32FSInfo;

          /**

           * If non-zero, indicates the sector number in the reserved area

           * of the volume of a copy of the boot record. Usually 6.

           * No value other than 6 is recommended.

           */

  uint16_t fat32BackBootBlock;

          /**

           * Reserved for future expansion. Code that formats FAT32 volumes

           * should always set all of the bytes of this field to 0.

           */

  uint8_t  fat32Reserved[12];

};

/** Type name for biosParmBlock */

typedef struct biosParmBlock bpb_t;

//------------------------------------------------------------------------------

/**

 * \struct fat32BootSector

 *

 * \brief Boot sector for a FAT16 or FAT32 volume.

 * 

 */  

struct fat32BootSector {

           /** X86 jmp to boot program */

  uint8_t  jmpToBootCode[3];

           /** informational only - don't depend on it */

  char     oemName[8];

           /** BIOS Parameter Block */

  bpb_t    bpb;

           /** for int0x13 use value 0X80 for hard drive */

  uint8_t  driveNumber;

           /** used by Windows NT - should be zero for FAT */

  uint8_t  reserved1;

           /** 0X29 if next three fields are valid */

  uint8_t  bootSignature;

           /** usually generated by combining date and time */

  uint32_t volumeSerialNumber;

           /** should match volume label in root dir */

  char     volumeLabel[11];

           /** informational only - don't depend on it */

  char     fileSystemType[8];

           /** X86 boot code */

  uint8_t  bootCode[420];

           /** must be 0X55 */

  uint8_t  bootSectorSig0;

           /** must be 0XAA */

  uint8_t  bootSectorSig1;

};

//------------------------------------------------------------------------------

// End Of Chain values for FAT entries

/** FAT16 end of chain value used by Microsoft. */

uint16_t const FAT16EOC = 0XFFFF;

/** Minimum value for FAT16 EOC.  Use to test for EOC. */

uint16_t const FAT16EOC_MIN = 0XFFF8;

/** FAT32 end of chain value used by Microsoft. */

uint32_t const FAT32EOC = 0X0FFFFFFF;

/** Minimum value for FAT32 EOC.  Use to test for EOC. */

uint32_t const FAT32EOC_MIN = 0X0FFFFFF8;

/** Mask a for FAT32 entry. Entries are 28 bits. */

uint32_t const FAT32MASK = 0X0FFFFFFF;

/** Type name for fat32BootSector */

typedef struct fat32BootSector fbs_t;

//------------------------------------------------------------------------------

/**

 * \struct directoryEntry

 * \brief FAT short directory entry

 *

 * Short means short 8.3 name, not the entry size.

 *  

 * Date Format. A FAT directory entry date stamp is a 16-bit field that is 

 * basically a date relative to the MS-DOS epoch of 01/01/1980. Here is the

 * format (bit 0 is the LSB of the 16-bit word, bit 15 is the MSB of the 

 * 16-bit word):

 *   

 * Bits 9-15: Count of years from 1980, valid value range 0-127 

 * inclusive (1980-2107).

 *   

 * Bits 5-8: Month of year, 1 = January, valid value range 1-12 inclusive.

 *

 * Bits 0-4: Day of month, valid value range 1-31 inclusive.

 *

 * Time Format. A FAT directory entry time stamp is a 16-bit field that has

 * a granularity of 2 seconds. Here is the format (bit 0 is the LSB of the 

 * 16-bit word, bit 15 is the MSB of the 16-bit word).

 *   

 * Bits 11-15: Hours, valid value range 0-23 inclusive.

 * 

 * Bits 5-10: Minutes, valid value range 0-59 inclusive.

 *      

 * Bits 0-4: 2-second count, valid value range 0-29 inclusive (0 - 58 seconds).

 *   

 * The valid time range is from Midnight 00:00:00 to 23:59:58.

 */

struct directoryEntry {

           /**

            * Short 8.3 name.

            * The first eight bytes contain the file name with blank fill.

            * The last three bytes contain the file extension with blank fill.

            */

  uint8_t  name[11];

          /** Entry attributes.

           *

           * The upper two bits of the attribute byte are reserved and should

           * always be set to 0 when a file is created and never modified or

           * looked at after that.  See defines that begin with DIR_ATT_.

           */

  uint8_t  attributes;

          /**

           * Reserved for use by Windows NT. Set value to 0 when a file is

           * created and never modify or look at it after that.

           */

  uint8_t  reservedNT;

          /**

           * The granularity of the seconds part of creationTime is 2 seconds

           * so this field is a count of tenths of a second and its valid

           * value range is 0-199 inclusive. (WHG note - seems to be hundredths)

           */

  uint8_t  creationTimeTenths;

           /** Time file was created. */

  uint16_t creationTime;

           /** Date file was created. */

  uint16_t creationDate;

          /**

           * Last access date. Note that there is no last access time, only

           * a date.  This is the date of last read or write. In the case of

           * a write, this should be set to the same date as lastWriteDate.

           */

  uint16_t lastAccessDate;

          /**

           * High word of this entry's first cluster number (always 0 for a

           * FAT12 or FAT16 volume).

           */

  uint16_t firstClusterHigh;

           /** Time of last write. File creation is considered a write. */

  uint16_t lastWriteTime;

           /** Date of last write. File creation is considered a write. */

  uint16_t lastWriteDate;

           /** Low word of this entry's first cluster number. */

  uint16_t firstClusterLow;

           /** 32-bit unsigned holding this file's size in bytes. */

  uint32_t fileSize;

};

//------------------------------------------------------------------------------

// Definitions for directory entries

//

/** Type name for directoryEntry */

typedef struct directoryEntry dir_t;

/** escape for name[0] = 0XE5 */

uint8_t const DIR_NAME_0XE5 = 0X05;

/** name[0] value for entry that is free after being "deleted" */

uint8_t const DIR_NAME_DELETED = 0XE5;

/** name[0] value for entry that is free and no allocated entries follow */

uint8_t const DIR_NAME_FREE = 0X00;

/** file is read-only */

uint8_t const DIR_ATT_READ_ONLY = 0X01;

/** File should hidden in directory listings */

uint8_t const DIR_ATT_HIDDEN = 0X02;

/** Entry is for a system file */

uint8_t const DIR_ATT_SYSTEM = 0X04;

/** Directory entry contains the volume label */

uint8_t const DIR_ATT_VOLUME_ID = 0X08;

/** Entry is for a directory */

uint8_t const DIR_ATT_DIRECTORY = 0X10;

/** Old DOS archive bit for backup support */

uint8_t const DIR_ATT_ARCHIVE = 0X20;

/** Test value for long name entry.  Test is

  (d->attributes & DIR_ATT_LONG_NAME_MASK) == DIR_ATT_LONG_NAME. */

uint8_t const DIR_ATT_LONG_NAME = 0X0F;

/** Test mask for long name entry */

uint8_t const DIR_ATT_LONG_NAME_MASK = 0X3F;

/** defined attribute bits */

uint8_t const DIR_ATT_DEFINED_BITS = 0X3F;

/** Directory entry is part of a long name */

static inline uint8_t DIR_IS_LONG_NAME(const dir_t* dir) {

  return (dir->attributes & DIR_ATT_LONG_NAME_MASK) == DIR_ATT_LONG_NAME;

}

/** Mask for file/subdirectory tests */

uint8_t const DIR_ATT_FILE_TYPE_MASK = (DIR_ATT_VOLUME_ID | DIR_ATT_DIRECTORY);

/** Directory entry is for a file */

static inline uint8_t DIR_IS_FILE(const dir_t* dir) {

  return (dir->attributes & DIR_ATT_FILE_TYPE_MASK) == 0;

}

/** Directory entry is for a subdirectory */

static inline uint8_t DIR_IS_SUBDIR(const dir_t* dir) {

  return (dir->attributes & DIR_ATT_FILE_TYPE_MASK) == DIR_ATT_DIRECTORY;

}

/** Directory entry is for a file or subdirectory */

static inline uint8_t DIR_IS_FILE_OR_SUBDIR(const dir_t* dir) {

  return (dir->attributes & DIR_ATT_VOLUME_ID) == 0;

}

#endif  // FatStructs_h