fat_access.c

Go to the documentation of this file.

//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
//                            FAT16/32 File IO Library
//                                    V2.6
//                              Ultra-Embedded.com
//                            Copyright 2003 - 2012
//
//                         Email: admin@ultra-embedded.com
//
//                                License: GPL
//   If you would like a version with a more permissive license for use in
//   closed source commercial applications please contact me for details.
//-----------------------------------------------------------------------------
//
// This file is part of FAT File IO Library.
//
// FAT File IO 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 2 of the License, or
// (at your option) any later version.
//
// FAT File IO 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 FAT File IO Library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
#include <string.h>
#include "fat_defs.h"
#include "fat_access.h"
#include "fat_table.h"
#include "fat_write.h"
#include "fat_string.h"
#include "fat_misc.h"
 
//-----------------------------------------------------------------------------
// fatfs_init: Load FAT Parameters
//-----------------------------------------------------------------------------
int fatfs_init(struct fatfs *fs) {
  uint8 num_of_fats;
  uint16 reserved_sectors;
  uint32 FATSz;
  uint32 root_dir_sectors;
  uint32 total_sectors;
  uint32 data_sectors;
  uint32 count_of_clusters;
  uint8 valid_partition = 0;
 
  fs->currentsector.address = FAT32_INVALID_CLUSTER;
  fs->currentsector.dirty = 0;
 
  fs->next_free_cluster = 0; // Invalid
 
  fatfs_fat_init(fs);
 
  // Make sure we have a read function (write function is optional)
  if (!fs->disk_io.read_media)
    return FAT_INIT_MEDIA_ACCESS_ERROR;
 
  // MBR: Sector 0 on the disk
  // NOTE: Some removeable media does not have this.
 
  // Load MBR (LBA 0) into the 512 byte buffer
  if (!fs->disk_io.read_media(0, fs->currentsector.sector, 1))
    return FAT_INIT_MEDIA_ACCESS_ERROR;
 
  // Make Sure 0x55 and 0xAA are at end of sector
  // (this should be the case regardless of the MBR or boot sector)
  if (fs->currentsector.sector[SIGNATURE_POSITION] != 0x55 || fs->currentsector.sector[SIGNATURE_POSITION + 1] != 0xAA)
    return FAT_INIT_INVALID_SIGNATURE;
 
  // Now check again using the access function to prove endian conversion function
  if (GET_16BIT_WORD(fs->currentsector.sector,
      SIGNATURE_POSITION) != SIGNATURE_VALUE)
    return FAT_INIT_ENDIAN_ERROR;
 
  // Verify packed structures
  if (sizeof(struct fat_dir_entry) != FAT_DIR_ENTRY_SIZE)
    return FAT_INIT_STRUCT_PACKING;
 
  // Check the partition type code
  switch (fs->currentsector.sector[PARTITION1_TYPECODE_LOCATION]) {
    case 0x0B:
    case 0x06:
    case 0x0C:
    case 0x0E:
    case 0x0F:
    case 0x05:
      valid_partition = 1;
      break;
    case 0x00:
      valid_partition = 0;
      break;
    default:
      if (fs->currentsector.sector[PARTITION1_TYPECODE_LOCATION] <= 0x06)
        valid_partition = 1;
      break;
  }
 
  // Read LBA Begin for the file system
  if (valid_partition)
    fs->lba_begin = GET_32BIT_WORD(fs->currentsector.sector, PARTITION1_LBA_BEGIN_LOCATION);
  // Else possibly MBR less disk
  else
    fs->lba_begin = 0;
 
  // Load Volume 1 table into sector buffer
  // (We may already have this in the buffer if MBR less drive!)
  if (!fs->disk_io.read_media(fs->lba_begin, fs->currentsector.sector, 1))
    return FAT_INIT_MEDIA_ACCESS_ERROR;
 
  // Make sure there are 512 bytes per cluster
  if (GET_16BIT_WORD(fs->currentsector.sector, 0x0B) != FAT_SECTOR_SIZE)
    return FAT_INIT_INVALID_SECTOR_SIZE;
 
  // Load Parameters of FAT partition
  fs->sectors_per_cluster = fs->currentsector.sector[BPB_SECPERCLUS];
  reserved_sectors = GET_16BIT_WORD(fs->currentsector.sector, BPB_RSVDSECCNT);
  num_of_fats = fs->currentsector.sector[BPB_NUMFATS];
  fs->root_entry_count = GET_16BIT_WORD(fs->currentsector.sector, BPB_ROOTENTCNT);
 
  if (GET_16BIT_WORD(fs->currentsector.sector, BPB_FATSZ16) != 0)
    fs->fat_sectors = GET_16BIT_WORD(fs->currentsector.sector, BPB_FATSZ16);
  else
    fs->fat_sectors = GET_32BIT_WORD(fs->currentsector.sector, BPB_FAT32_FATSZ32);
 
  // For FAT32 (which this may be)
  fs->rootdir_first_cluster = GET_32BIT_WORD(fs->currentsector.sector, BPB_FAT32_ROOTCLUS);
  fs->fs_info_sector = GET_16BIT_WORD(fs->currentsector.sector, BPB_FAT32_FSINFO);
 
  // For FAT16 (which this may be), rootdir_first_cluster is actuall rootdir_first_sector
  fs->rootdir_first_sector = reserved_sectors + (num_of_fats * fs->fat_sectors);
  fs->rootdir_sectors = ((fs->root_entry_count * 32) + (FAT_SECTOR_SIZE - 1)) / FAT_SECTOR_SIZE;
 
  // First FAT LBA address
  fs->fat_begin_lba = fs->lba_begin + reserved_sectors;
 
  // The address of the first data cluster on this volume
  fs->cluster_begin_lba = fs->fat_begin_lba + (num_of_fats * fs->fat_sectors);
 
  if (GET_16BIT_WORD(fs->currentsector.sector, 0x1FE) != 0xAA55) // This signature should be AA55
    return FAT_INIT_INVALID_SIGNATURE;
 
  // Calculate the root dir sectors
  root_dir_sectors = ((GET_16BIT_WORD(fs->currentsector.sector, BPB_ROOTENTCNT) * 32) + (GET_16BIT_WORD(fs->currentsector.sector, BPB_BYTSPERSEC) - 1)) / GET_16BIT_WORD(fs->currentsector.sector, BPB_BYTSPERSEC);
 
  if (GET_16BIT_WORD(fs->currentsector.sector, BPB_FATSZ16) != 0)
    FATSz = GET_16BIT_WORD(fs->currentsector.sector, BPB_FATSZ16);
  else
    FATSz = GET_32BIT_WORD(fs->currentsector.sector, BPB_FAT32_FATSZ32);
 
  if (GET_16BIT_WORD(fs->currentsector.sector, BPB_TOTSEC16) != 0)
    total_sectors = GET_16BIT_WORD(fs->currentsector.sector, BPB_TOTSEC16);
  else
    total_sectors = GET_32BIT_WORD(fs->currentsector.sector, BPB_TOTSEC32);
 
  data_sectors = total_sectors - (GET_16BIT_WORD(fs->currentsector.sector, BPB_RSVDSECCNT) + (fs->currentsector.sector[BPB_NUMFATS] * FATSz) + root_dir_sectors);
 
  // Find out which version of FAT this is...
  if (fs->sectors_per_cluster != 0) {
    count_of_clusters = data_sectors / fs->sectors_per_cluster;
 
    if (count_of_clusters < 4085)
      // Volume is FAT12
      return FAT_INIT_WRONG_FILESYS_TYPE;
    else if (count_of_clusters < 65525) {
      // Clear this FAT32 specific param
      fs->rootdir_first_cluster = 0;
 
      // Volume is FAT16
      fs->fat_type = FAT_TYPE_16;
      return FAT_INIT_OK;
    }
    else {
      // Volume is FAT32
      fs->fat_type = FAT_TYPE_32;
      return FAT_INIT_OK;
    }
  }
  else
    return FAT_INIT_WRONG_FILESYS_TYPE;
}
//-----------------------------------------------------------------------------
// fatfs_lba_of_cluster: This function converts a cluster number into a sector /
// LBA number.
//-----------------------------------------------------------------------------
uint32 fatfs_lba_of_cluster(struct fatfs *fs, uint32 Cluster_Number) {
  if (fs->fat_type == FAT_TYPE_16)
    return (fs->cluster_begin_lba + (fs->root_entry_count * 32 / FAT_SECTOR_SIZE) + ((Cluster_Number - 2) * fs->sectors_per_cluster));
  else
    return ((fs->cluster_begin_lba + ((Cluster_Number - 2) * fs->sectors_per_cluster)));
}
//-----------------------------------------------------------------------------
// fatfs_sector_read:
//-----------------------------------------------------------------------------
int fatfs_sector_read(struct fatfs *fs, uint32 lba, uint8 *target, uint32 count) {
  return fs->disk_io.read_media(lba, target, count);
}
//-----------------------------------------------------------------------------
// fatfs_sector_write:
//-----------------------------------------------------------------------------
int fatfs_sector_write(struct fatfs *fs, uint32 lba, uint8 *target, uint32 count) {
  return fs->disk_io.write_media(lba, target, count);
}
//-----------------------------------------------------------------------------
// fatfs_sector_reader: From the provided startcluster and sector offset
// Returns True if success, returns False if not (including if read out of range)
//-----------------------------------------------------------------------------
int fatfs_sector_reader(struct fatfs *fs, uint32 start_cluster, uint32 offset, uint8 *target) {
  uint32 sector_to_read = 0;
  uint32 cluster_to_read = 0;
  uint32 cluster_chain = 0;
  uint32 i;
  uint32 lba;
 
  // FAT16 Root directory
  if (fs->fat_type == FAT_TYPE_16 && start_cluster == 0) {
    if (offset < fs->rootdir_sectors)
      lba = fs->lba_begin + fs->rootdir_first_sector + offset;
    else
      return 0;
  }
  // FAT16/32 Other
  else {
    // Set start of cluster chain to initial value
    cluster_chain = start_cluster;
 
    // Find parameters
    cluster_to_read = offset / fs->sectors_per_cluster;
    sector_to_read = offset - (cluster_to_read * fs->sectors_per_cluster);
 
    // Follow chain to find cluster to read
    for (i = 0; i < cluster_to_read; i++)
      cluster_chain = fatfs_find_next_cluster(fs, cluster_chain);
 
    // If end of cluster chain then return false
    if (cluster_chain == FAT32_LAST_CLUSTER)
      return 0;
 
    // Calculate sector address
    lba = fatfs_lba_of_cluster(fs, cluster_chain) + sector_to_read;
  }
 
  // User provided target array
  if (target)
    return fs->disk_io.read_media(lba, target, 1);
  // Else read sector if not already loaded
  else if (lba != fs->currentsector.address) {
    fs->currentsector.address = lba;
    return fs->disk_io.read_media(fs->currentsector.address, fs->currentsector.sector, 1);
  }
  else
    return 1;
}
//-----------------------------------------------------------------------------
// fatfs_read_sector: Read from the provided cluster and sector offset
// Returns True if success, returns False if not
//-----------------------------------------------------------------------------
int fatfs_read_sector(struct fatfs *fs, uint32 cluster, uint32 sector, uint8 *target) {
  // FAT16 Root directory
  if (fs->fat_type == FAT_TYPE_16 && cluster == 0) {
    uint32 lba;
 
    // In FAT16, there are a limited amount of sectors in root dir!
    if (sector < fs->rootdir_sectors)
      lba = fs->lba_begin + fs->rootdir_first_sector + sector;
    else
      return 0;
 
    // User target buffer passed in
    if (target) {
      // Read from disk
      return fs->disk_io.read_media(lba, target, 1);
    }
    else {
      // Calculate read address
      fs->currentsector.address = lba;
 
      // Read from disk
      return fs->disk_io.read_media(fs->currentsector.address, fs->currentsector.sector, 1);
    }
  }
  // FAT16/32 Other
  else {
    // User target buffer passed in
    if (target) {
      // Calculate read address
      uint32 lba = fatfs_lba_of_cluster(fs, cluster) + sector;
 
      // Read from disk
      return fs->disk_io.read_media(lba, target, 1);
    }
    else {
      // Calculate write address
      fs->currentsector.address = fatfs_lba_of_cluster(fs, cluster) + sector;
 
      // Read from disk
      return fs->disk_io.read_media(fs->currentsector.address, fs->currentsector.sector, 1);
    }
  }
}
//-----------------------------------------------------------------------------
// fatfs_write_sector: Write to the provided cluster and sector offset
// Returns True if success, returns False if not
//-----------------------------------------------------------------------------
#if FATFS_INC_WRITE_SUPPORT
int fatfs_write_sector(struct fatfs *fs, uint32 cluster, uint32 sector, uint8 *target) {
  // No write access?
  if (!fs->disk_io.write_media)
    return 0;
 
  // FAT16 Root directory
  if (fs->fat_type == FAT_TYPE_16 && cluster == 0) {
    uint32 lba;
 
    // In FAT16 we cannot extend the root dir!
    if (sector < fs->rootdir_sectors)
      lba = fs->lba_begin + fs->rootdir_first_sector + sector;
    else
      return 0;
 
    // User target buffer passed in
    if (target) {
      // Write to disk
      return fs->disk_io.write_media(lba, target, 1);
    }
    else {
      // Calculate write address
      fs->currentsector.address = lba;
 
      // Write to disk
      return fs->disk_io.write_media(fs->currentsector.address, fs->currentsector.sector, 1);
    }
  }
  // FAT16/32 Other
  else {
    // User target buffer passed in
    if (target) {
      // Calculate write address
      uint32 lba = fatfs_lba_of_cluster(fs, cluster) + sector;
 
      // Write to disk
      return fs->disk_io.write_media(lba, target, 1);
    }
    else {
      // Calculate write address
      fs->currentsector.address = fatfs_lba_of_cluster(fs, cluster) + sector;
 
      // Write to disk
      return fs->disk_io.write_media(fs->currentsector.address, fs->currentsector.sector, 1);
    }
  }
}
#endif
//-----------------------------------------------------------------------------
// fatfs_show_details: Show the details about the filesystem
//-----------------------------------------------------------------------------
void fatfs_show_details(struct fatfs *fs) {
  FAT_PRINTF(("FAT details:\r\n"));
  FAT_PRINTF((" Type =%s", (fs->fat_type == FAT_TYPE_32) ? "FAT32": "FAT16"));
  FAT_PRINTF((" Root Dir First Cluster = %x\r\n", fs->rootdir_first_cluster));
  FAT_PRINTF((" FAT Begin LBA = 0x%x\r\n",fs->fat_begin_lba));
  FAT_PRINTF((" Cluster Begin LBA = 0x%x\r\n",fs->cluster_begin_lba));
  FAT_PRINTF((" Sectors Per Cluster = %d\r\n", fs->sectors_per_cluster));
}
//-----------------------------------------------------------------------------
// fatfs_get_root_cluster: Get the root dir cluster
//-----------------------------------------------------------------------------
uint32 fatfs_get_root_cluster(struct fatfs *fs) {
  // NOTE: On FAT16 this will be 0 which has a special meaning...
  return fs->rootdir_first_cluster;
}
//-------------------------------------------------------------
// fatfs_get_file_entry: Find the file entry for a filename
//-------------------------------------------------------------
uint32 fatfs_get_file_entry(struct fatfs *fs, uint32 Cluster, char *name_to_find, struct fat_dir_entry *sfEntry) {
  uint8 item = 0;
  uint16 recordoffset = 0;
  uint8 i = 0;
  int x = 0;
  char *long_filename = NULL;
  char short_filename[13];
  struct lfn_cache lfn;
  int dotRequired = 0;
  struct fat_dir_entry *directoryEntry;
 
  fatfs_lfn_cache_init(&lfn, 1);
 
  // Main cluster following loop
  while (1) {
    // Read sector
    if (fatfs_sector_reader(fs, Cluster, x++, 0)) { // If sector read was successfull
      // Analyse Sector
      for (item = 0; item < FAT_DIR_ENTRIES_PER_SECTOR; item++) {
        // Create the multiplier for sector access
        recordoffset = FAT_DIR_ENTRY_SIZE * item;
 
        // Overlay directory entry over buffer
        directoryEntry = (struct fat_dir_entry*) (fs->currentsector.sector + recordoffset);
 
#if FATFS_INC_LFN_SUPPORT
 
        if (fatfs_entry_lfn_text(directoryEntry)) { // Long File Name Text Found
          fatfs_lfn_cache_entry(&lfn, fs->currentsector.sector + recordoffset);
        }
        else if (fatfs_entry_lfn_invalid(directoryEntry)) { // If Invalid record found delete any long file name information collated
 
          fatfs_lfn_cache_init(&lfn, 0);
        }
        else if (fatfs_entry_lfn_exists(&lfn, directoryEntry)) { // Normal SFN Entry and Long text exists
          long_filename = fatfs_lfn_cache_get(&lfn);
 
          // Compare names to see if they match
          if (fatfs_compare_names(long_filename, name_to_find)) {
            memcpy(sfEntry, directoryEntry, sizeof(struct fat_dir_entry));
            return 1;
          }
 
          fatfs_lfn_cache_init(&lfn, 0);
        }
        else {
#endif
          if (fatfs_entry_sfn_only(directoryEntry)) { // Normal Entry, only 8.3 Text
            memset(short_filename, 0, sizeof(short_filename));
 
            // Copy name to string
            for (i = 0; i < 8; i++)
              short_filename[i] = directoryEntry->Name[i];
 
            // Extension
            dotRequired = 0;
            for (i = 8; i < 11; i++) {
              short_filename[i + 1] = directoryEntry->Name[i];
              if (directoryEntry->Name[i] != ' ')
                dotRequired = 1;
            }
 
            // Dot only required if extension present
            if (dotRequired) {
              // If not . or .. entry
              if (short_filename[0] != '.')
                short_filename[8] = '.';
              else
                short_filename[8] = ' ';
            }
            else
              short_filename[8] = ' ';
 
            // Compare names to see if they match
            if (fatfs_compare_names(short_filename, name_to_find)) {
              memcpy(sfEntry, directoryEntry, sizeof(struct fat_dir_entry));
              return 1;
            }
 
            fatfs_lfn_cache_init(&lfn, 0);
          }
#if FATFS_INC_LFN_SUPPORT
        }
#endif
 
      } // End of for
    }
    else
      break;
  } // End of while loop
 
  return 0;
}
//-------------------------------------------------------------
// fatfs_sfn_exists: Check if a short filename exists.
// NOTE: shortname is XXXXXXXXYYY not XXXXXXXX.YYY
//-------------------------------------------------------------
#if FATFS_INC_WRITE_SUPPORT
int fatfs_sfn_exists(struct fatfs *fs, uint32 Cluster, char *shortname) {
  uint8 item = 0;
  uint16 recordoffset = 0;
  int x = 0;
  struct fat_dir_entry *directoryEntry;
 
  // Main cluster following loop
  while (1) {
    // Read sector
    if (fatfs_sector_reader(fs, Cluster, x++, 0)) // If sector read was successfull
        {
      // Analyse Sector
      for (item = 0; item < FAT_DIR_ENTRIES_PER_SECTOR; item++) {
        // Create the multiplier for sector access
        recordoffset = FAT_DIR_ENTRY_SIZE * item;
 
        // Overlay directory entry over buffer
        directoryEntry = (struct fat_dir_entry*) (fs->currentsector.sector + recordoffset);
 
#if FATFS_INC_LFN_SUPPORT
        // Long File Name Text Found
        if (fatfs_entry_lfn_text(directoryEntry))
          ;
 
        // If Invalid record found delete any long file name information collated
        else if (fatfs_entry_lfn_invalid(directoryEntry))
          ;
        else
#endif
        // Normal Entry, only 8.3 Text
        if (fatfs_entry_sfn_only(directoryEntry)) {
          if (strncmp((const char*) directoryEntry->Name, shortname, 11) == 0)
            return 1;
        }
      } // End of if
    }
    else
      break;
  } // End of while loop
 
  return 0;
}
#endif
//-------------------------------------------------------------
// fatfs_update_timestamps: Update date/time details
//-------------------------------------------------------------
#if FATFS_INC_TIME_DATE_SUPPORT
int fatfs_update_timestamps(struct fat_dir_entry *directoryEntry, int create, int modify, int access)
{
    time_t time_now;
    struct tm * time_info;
    uint16 fat_time;
    uint16 fat_date;
 
    // Get system time
    time(&time_now);
 
    // Convert to local time
    time_info = localtime(&time_now);
 
    // Convert time to FAT format
    fat_time = fatfs_convert_to_fat_time(time_info->tm_hour, time_info->tm_min, time_info->tm_sec);
 
    // Convert date to FAT format
    fat_date = fatfs_convert_to_fat_date(time_info->tm_mday, time_info->tm_mon + 1, time_info->tm_year + 1900);
 
    // Update requested fields
    if (create)
    {
        directoryEntry->CrtTime[1] = fat_time >> 8;
        directoryEntry->CrtTime[0] = fat_time >> 0;
        directoryEntry->CrtDate[1] = fat_date >> 8;
        directoryEntry->CrtDate[0] = fat_date >> 0;
    }
 
    if (modify)
    {
        directoryEntry->WrtTime[1] = fat_time >> 8;
        directoryEntry->WrtTime[0] = fat_time >> 0;
        directoryEntry->WrtDate[1] = fat_date >> 8;
        directoryEntry->WrtDate[0] = fat_date >> 0;
    }
 
    if (access)
    {
        directoryEntry->LstAccDate[1] = fat_time >> 8;
        directoryEntry->LstAccDate[0] = fat_time >> 0;
        directoryEntry->LstAccDate[1] = fat_date >> 8;
        directoryEntry->LstAccDate[0] = fat_date >> 0;
    }
 
    return 1;
}
#endif
 
//-------------------------------------------------------------
// fatfs_update_file_length: Find a SFN entry and update it
// NOTE: shortname is XXXXXXXXYYY not XXXXXXXX.YYY
//-------------------------------------------------------------
#if FATFS_INC_WRITE_SUPPORT
int fatfs_update_file_length(struct fatfs *fs, uint32 Cluster, char *shortname, uint32 fileLength) {
  uint8 item = 0;
  uint16 recordoffset = 0;
  int x = 0;
  struct fat_dir_entry *directoryEntry;
 
  // No write access?
  if (!fs->disk_io.write_media)
    return 0;
 
  // Main cluster following loop
  while (1) {
    // Read sector
    if (fatfs_sector_reader(fs, Cluster, x++, 0)) // If sector read was successfull
        {
      // Analyse Sector
      for (item = 0; item < FAT_DIR_ENTRIES_PER_SECTOR; item++) {
        // Create the multiplier for sector access
        recordoffset = FAT_DIR_ENTRY_SIZE * item;
 
        // Overlay directory entry over buffer
        directoryEntry = (struct fat_dir_entry*) (fs->currentsector.sector + recordoffset);
 
#if FATFS_INC_LFN_SUPPORT
        // Long File Name Text Found
        if (fatfs_entry_lfn_text(directoryEntry))
          ;
 
        // If Invalid record found delete any long file name information collated
        else if (fatfs_entry_lfn_invalid(directoryEntry))
          ;
 
        // Normal Entry, only 8.3 Text
        else
#endif
        if (fatfs_entry_sfn_only(directoryEntry)) {
          if (strncmp((const char*) directoryEntry->Name, shortname, 11) == 0) {
            directoryEntry->FileSize = FAT_HTONL(fileLength);
 
#if FATFS_INC_TIME_DATE_SUPPORT
                        // Update access / modify time & date
                        fatfs_update_timestamps(directoryEntry, 0, 1, 1);
#endif
 
            // Update sfn entry
            memcpy((uint8*) (fs->currentsector.sector + recordoffset), (uint8*) directoryEntry, sizeof(struct fat_dir_entry));
 
            // Write sector back
            return fs->disk_io.write_media(fs->currentsector.address, fs->currentsector.sector, 1);
          }
        }
      } // End of if
    }
    else
      break;
  } // End of while loop
 
  return 0;
}
#endif
//-------------------------------------------------------------
// fatfs_mark_file_deleted: Find a SFN entry and mark if as deleted
// NOTE: shortname is XXXXXXXXYYY not XXXXXXXX.YYY
//-------------------------------------------------------------
#if FATFS_INC_WRITE_SUPPORT
int fatfs_mark_file_deleted(struct fatfs *fs, uint32 Cluster, char *shortname) {
  uint8 item = 0;
  uint16 recordoffset = 0;
  int x = 0;
  struct fat_dir_entry *directoryEntry;
 
  // No write access?
  if (!fs->disk_io.write_media)
    return 0;
 
  // Main cluster following loop
  while (1) {
    // Read sector
    if (fatfs_sector_reader(fs, Cluster, x++, 0)) // If sector read was successfull
        {
      // Analyse Sector
      for (item = 0; item < FAT_DIR_ENTRIES_PER_SECTOR; item++) {
        // Create the multiplier for sector access
        recordoffset = FAT_DIR_ENTRY_SIZE * item;
 
        // Overlay directory entry over buffer
        directoryEntry = (struct fat_dir_entry*) (fs->currentsector.sector + recordoffset);
 
#if FATFS_INC_LFN_SUPPORT
        // Long File Name Text Found
        if (fatfs_entry_lfn_text(directoryEntry))
          ;
 
        // If Invalid record found delete any long file name information collated
        else if (fatfs_entry_lfn_invalid(directoryEntry))
          ;
 
        // Normal Entry, only 8.3 Text
        else
#endif
        if (fatfs_entry_sfn_only(directoryEntry)) {
          if (strncmp((const char*) directoryEntry->Name, shortname, 11) == 0) {
            // Mark as deleted
            directoryEntry->Name[0] = FILE_HEADER_DELETED;
 
#if FATFS_INC_TIME_DATE_SUPPORT
                        // Update access / modify time & date
                        fatfs_update_timestamps(directoryEntry, 0, 1, 1);
#endif
 
            // Update sfn entry
            memcpy((uint8*) (fs->currentsector.sector + recordoffset), (uint8*) directoryEntry, sizeof(struct fat_dir_entry));
 
            // Write sector back
            return fs->disk_io.write_media(fs->currentsector.address, fs->currentsector.sector, 1);
          }
        }
      } // End of if
    }
    else
      break;
  } // End of while loop
 
  return 0;
}
#endif
//-----------------------------------------------------------------------------
// fatfs_list_directory_start: Initialise a directory listing procedure
//-----------------------------------------------------------------------------
#if FATFS_DIR_LIST_SUPPORT
void fatfs_list_directory_start(struct fatfs *fs, struct fs_dir_list_status *dirls, uint32 StartCluster) {
  dirls->cluster = StartCluster;
  dirls->sector = 0;
  dirls->offset = 0;
}
#endif
//-----------------------------------------------------------------------------
// fatfs_list_directory_next: Get the next entry in the directory.
// Returns: 1 = found, 0 = end of listing
//-----------------------------------------------------------------------------
#if FATFS_DIR_LIST_SUPPORT
int fatfs_list_directory_next(struct fatfs *fs, struct fs_dir_list_status *dirls, struct fs_dir_ent *entry) {
  uint8 i, item;
  uint16 recordoffset;
  struct fat_dir_entry *directoryEntry;
  char *long_filename = NULL;
  char short_filename[13];
  struct lfn_cache lfn;
  int dotRequired = 0;
  int result = 0;
 
  // Initialise LFN cache first
  fatfs_lfn_cache_init(&lfn, 0);
 
  while (1) {
    // If data read OK
    if (fatfs_sector_reader(fs, dirls->cluster, dirls->sector, 0)) {
      // Maximum of 16 directory entries
      for (item = dirls->offset; item < FAT_DIR_ENTRIES_PER_SECTOR; item++) {
        // Increase directory offset
        recordoffset = FAT_DIR_ENTRY_SIZE * item;
 
        // Overlay directory entry over buffer
        directoryEntry = (struct fat_dir_entry*) (fs->currentsector.sector + recordoffset);
 
#if FATFS_INC_LFN_SUPPORT
        // Long File Name Text Found
        if (fatfs_entry_lfn_text(directoryEntry))
          fatfs_lfn_cache_entry(&lfn, fs->currentsector.sector + recordoffset);
 
        // If Invalid record found delete any long file name information collated
        else if (fatfs_entry_lfn_invalid(directoryEntry))
          fatfs_lfn_cache_init(&lfn, 0);
 
        // Normal SFN Entry and Long text exists
        else if (fatfs_entry_lfn_exists(&lfn, directoryEntry)) {
          // Get text
          long_filename = fatfs_lfn_cache_get(&lfn);
          strncpy(entry->filename, long_filename, FATFS_MAX_LONG_FILENAME - 1);
 
          if (fatfs_entry_is_dir(directoryEntry))
            entry->is_dir = 1;
          else
            entry->is_dir = 0;
 
#if FATFS_INC_TIME_DATE_SUPPORT
                    // Get time / dates
                    entry->create_time = ((uint16)directoryEntry->CrtTime[1] << 8) | directoryEntry->CrtTime[0];
                    entry->create_date = ((uint16)directoryEntry->CrtDate[1] << 8) | directoryEntry->CrtDate[0];
                    entry->access_date = ((uint16)directoryEntry->LstAccDate[1] << 8) | directoryEntry->LstAccDate[0];
                    entry->write_time  = ((uint16)directoryEntry->WrtTime[1] << 8) | directoryEntry->WrtTime[0];
                    entry->write_date  = ((uint16)directoryEntry->WrtDate[1] << 8) | directoryEntry->WrtDate[0];
#endif
 
          entry->size = FAT_HTONL(directoryEntry->FileSize);
          entry->cluster = (FAT_HTONS(directoryEntry->FstClusHI) << 16) | FAT_HTONS(directoryEntry->FstClusLO);
 
          // Next starting position
          dirls->offset = item + 1;
          result = 1;
          return 1;
        }
        // Normal Entry, only 8.3 Text
        else
#endif
        if (fatfs_entry_sfn_only(directoryEntry)) {
          fatfs_lfn_cache_init(&lfn, 0);
 
          memset(short_filename, 0, sizeof(short_filename));
 
          // Copy name to string
          for (i = 0; i < 8; i++)
            short_filename[i] = directoryEntry->Name[i];
 
          // Extension
          dotRequired = 0;
          for (i = 8; i < 11; i++) {
            short_filename[i + 1] = directoryEntry->Name[i];
            if (directoryEntry->Name[i] != ' ')
              dotRequired = 1;
          }
 
          // Dot only required if extension present
          if (dotRequired) {
            // If not . or .. entry
            if (short_filename[0] != '.')
              short_filename[8] = '.';
            else
              short_filename[8] = ' ';
          }
          else
            short_filename[8] = ' ';
 
          fatfs_get_sfn_display_name(entry->filename, short_filename);
 
          if (fatfs_entry_is_dir(directoryEntry))
            entry->is_dir = 1;
          else
            entry->is_dir = 0;
 
#if FATFS_INC_TIME_DATE_SUPPORT
                    // Get time / dates
                    entry->create_time = ((uint16)directoryEntry->CrtTime[1] << 8) | directoryEntry->CrtTime[0];
                    entry->create_date = ((uint16)directoryEntry->CrtDate[1] << 8) | directoryEntry->CrtDate[0];
                    entry->access_date = ((uint16)directoryEntry->LstAccDate[1] << 8) | directoryEntry->LstAccDate[0];
                    entry->write_time  = ((uint16)directoryEntry->WrtTime[1] << 8) | directoryEntry->WrtTime[0];
                    entry->write_date  = ((uint16)directoryEntry->WrtDate[1] << 8) | directoryEntry->WrtDate[0];
#endif
 
          entry->size = FAT_HTONL(directoryEntry->FileSize);
          entry->cluster = (FAT_HTONS(directoryEntry->FstClusHI) << 16) | FAT_HTONS(directoryEntry->FstClusLO);
 
          // Next starting position
          dirls->offset = item + 1;
          result = 1;
          return 1;
        }
      } // end of for
 
      // If reached end of the dir move onto next sector
      dirls->sector++;
      dirls->offset = 0;
    }
    else
      break;
  }
 
  return result;
}
#endif