src/main/io/asyncfatfs/fat_standard.h

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