src/main/io/asyncfatfs/fat_standard.c

   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 #include <ctype.h>
  22
  23 #include "platform.h"
  24
  25 #include "fat_standard.h"
  26
  27 bool fat16_isEndOfChainMarker(uint16_t clusterNumber)
  28 {
  29     return clusterNumber >= 0xFFF8;
  30 }
  31
  32 // Pass the cluster number after fat32_decodeClusterNumber().
  33 bool fat32_isEndOfChainMarker(uint32_t clusterNumber)
  34 {
  35     return clusterNumber >= 0x0FFFFFF8;
  36 }
  37
  38 /**
  39  * FAT32 cluster numbers are really only 28 bits, and the top 4 bits must be left alone and not treated as part of the
  40  * cluster number (so various FAT drivers can use those bits for their own purposes, or they can be used in later
  41  * extensions)
  42  */
  43 uint32_t fat32_decodeClusterNumber(uint32_t clusterNumber)
  44 {
  45     return clusterNumber & 0x0FFFFFFF;
  46 }
  47
  48 // fat32 needs fat32_decodeClusterNumber() applied first.
  49 bool fat_isFreeSpace(uint32_t clusterNumber)
  50 {
  51     return clusterNumber == 0;
  52 }
  53
  54 bool fat_isDirectoryEntryTerminator(fatDirectoryEntry_t *entry)
  55 {
  56     return entry->filename[0] == 0x00;
  57 }
  58
  59 bool fat_isDirectoryEntryEmpty(fatDirectoryEntry_t *entry)
  60 {
  61     return (unsigned char) entry->filename[0] == FAT_DELETED_FILE_MARKER;
  62 }
  63
  64 /**
  65  * Convert the given "prefix.ext" style filename to the FAT format to be stored on disk.
  66  *
  67  * fatFilename must point to a buffer which is FAT_FILENAME_LENGTH bytes long. The buffer is not null-terminated.
  68  */
  69 void fat_convertFilenameToFATStyle(const char *filename, uint8_t *fatFilename)
  70 {
  71     for (int i = 0; i < 8; i++) {
  72         if (*filename == '\0' || *filename == '.') {
  73             *fatFilename = ' ';
  74         } else {
  75             *fatFilename = toupper((unsigned char)*filename);
  76             filename++;
  77         }
  78         fatFilename++;
  79     }
  80
  81     if (*filename == '.') {
  82         filename++;
  83     }
  84
  85     for (int i = 0; i < 3; i++) {
  86          if (*filename == '\0') {
  87              *fatFilename = ' ';
  88          } else {
  89              *fatFilename = toupper((unsigned char)*filename);
  90              filename++;
  91          }
  92          fatFilename++;
  93      }
  94 }