src/main/io/asyncfatfs/fat_standard.h

   1 /*
   2  * This file is part of Cleanflight and Betaflight.
   3  *
   4  * Cleanflight and Betaflight are free software. You can redistribute
   5  * this software and/or modify this software under the terms of the
   6  * GNU General Public License as published by the Free Software
   7  * Foundation, either version 3 of the License, or (at your option)
   8  * any later version.
   9  *
  10  * Cleanflight and Betaflight are distributed in the hope that they
  11  * will be useful, but WITHOUT ANY WARRANTY; without even the implied
  12  * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  13  * See the GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this software.
  17  *
  18  * If not, see <http://www.gnu.org/licenses/>.
  19  */
  20
  21 #pragma once
  22
  23 #include <stdint.h>
  24 #include <stdbool.h>
  25
  26 #define MBR_PARTITION_TYPE_FAT16     0x06
  27 #define MBR_PARTITION_TYPE_FAT32     0x0B
  28 #define MBR_PARTITION_TYPE_FAT32_LBA 0x0C
  29 #define MBR_PARTITION_TYPE_FAT16_LBA 0x0E
  30
  31 // Signature bytes found at index 510 and 511 in the volume ID sector
  32 #define FAT_VOLUME_ID_SIGNATURE_1 0x55
  33 #define FAT_VOLUME_ID_SIGNATURE_2 0xAA
  34
  35 #define FAT_DIRECTORY_ENTRY_SIZE 32
  36 #define FAT_SMALLEST_LEGAL_CLUSTER_NUMBER 2
  37
  38 #define FAT_MAXIMUM_FILESIZE 0xFFFFFFFF
  39
  40 #define FAT12_MAX_CLUSTERS 4084
  41 #define FAT16_MAX_CLUSTERS 65524
  42
  43 #define FAT_FILE_ATTRIBUTE_READ_ONLY 0x01
  44 #define FAT_FILE_ATTRIBUTE_HIDDEN    0x02
  45 #define FAT_FILE_ATTRIBUTE_SYSTEM    0x04
  46 #define FAT_FILE_ATTRIBUTE_VOLUME_ID 0x08
  47 #define FAT_FILE_ATTRIBUTE_DIRECTORY 0x10
  48 #define FAT_FILE_ATTRIBUTE_ARCHIVE   0x20
  49
  50 #define FAT_FILENAME_LENGTH 11
  51 #define FAT_DELETED_FILE_MARKER 0xE5
  52
  53 #define FAT_MAKE_DATE(year, month, day)     (day | (month << 5) | ((year - 1980) << 9))
  54 #define FAT_MAKE_TIME(hour, minute, second) ((second / 2) | (minute << 5) | (hour << 11))
  55
  56 typedef enum {
  57     FAT_FILESYSTEM_TYPE_INVALID,
  58     FAT_FILESYSTEM_TYPE_FAT12,
  59     FAT_FILESYSTEM_TYPE_FAT16,
  60     FAT_FILESYSTEM_TYPE_FAT32
  61 } fatFilesystemType_e;
  62
  63 typedef struct mbrPartitionEntry_t {
  64     uint8_t bootFlag;
  65     uint8_t chsBegin[3];
  66     uint8_t type;
  67     uint8_t chsEnd[3];
  68     uint32_t lbaBegin;
  69     uint32_t numSectors;
  70 } __attribute__((packed)) mbrPartitionEntry_t;
  71
  72 typedef struct fat16Descriptor_t {
  73     uint8_t driveNumber;
  74     uint8_t reserved1;
  75     uint8_t bootSignature;
  76     uint32_t volumeID;
  77     char volumeLabel[11];
  78     char fileSystemType[8];
  79 } __attribute__((packed)) fat16Descriptor_t;
  80
  81 typedef struct fat32Descriptor_t {
  82     uint32_t FATSize32;
  83     uint16_t extFlags;
  84     uint16_t fsVer;
  85     uint32_t rootCluster;
  86     uint16_t fsInfo;
  87     uint16_t backupBootSector;
  88     uint8_t reserved[12];
  89     uint8_t driveNumber;
  90     uint8_t reserved1;
  91     uint8_t bootSignature;
  92     uint32_t volumeID;
  93     char volumeLabel[11];
  94     char fileSystemType[8];
  95 } __attribute__((packed)) fat32Descriptor_t;
  96
  97 typedef struct fatVolumeID_t {
  98     uint8_t jmpBoot[3];
  99     char oemName[8];
 100     uint16_t bytesPerSector;
 101     uint8_t sectorsPerCluster;
 102     uint16_t reservedSectorCount;
 103     uint8_t numFATs;
 104     uint16_t rootEntryCount;
 105     uint16_t totalSectors16;
 106     uint8_t media;
 107     uint16_t FATSize16;
 108     uint16_t sectorsPerTrack;
 109     uint16_t numHeads;
 110     uint32_t hiddenSectors;
 111     uint32_t totalSectors32;
 112     union {
 113         fat16Descriptor_t fat16;
 114         fat32Descriptor_t fat32;
 115     } fatDescriptor;
 116 } __attribute__((packed)) fatVolumeID_t;
 117
 118 typedef struct fatDirectoryEntry_t {
 119     char filename[FAT_FILENAME_LENGTH];
 120     uint8_t attrib;
 121     uint8_t ntReserved;
 122     uint8_t creationTimeTenths;
 123     uint16_t creationTime;
 124     uint16_t creationDate;
 125     uint16_t lastAccessDate;
 126     uint16_t firstClusterHigh;
 127     uint16_t lastWriteTime;
 128     uint16_t lastWriteDate;
 129     uint16_t firstClusterLow;
 130     uint32_t fileSize;
 131 } __attribute__((packed)) fatDirectoryEntry_t;
 132
 133 uint32_t fat32_decodeClusterNumber(uint32_t clusterNumber);
 134
 135 bool fat32_isEndOfChainMarker(uint32_t clusterNumber);
 136 bool fat16_isEndOfChainMarker(uint16_t clusterNumber);
 137
 138 bool fat_isFreeSpace(uint32_t clusterNumber);
 139
 140 bool fat_isDirectoryEntryTerminator(fatDirectoryEntry_t *entry);
 141 bool fat_isDirectoryEntryEmpty(fatDirectoryEntry_t *entry);
 142
 143 void fat_convertFilenameToFATStyle(const char *filename, uint8_t *fatFilename);