Stack Overflow
Stack Overflow

Questions tagged [fat]

FAT short for File Allocation Table is the name of a computer file system architecture and a family of industry standard file systems utilizing it.

188 questions
1
vote
0 answers

Out of memory when exporting a FAT partition using NFS

After several hours of data transfer to a FAT partition using an NFSv3 server the server has no free memory left. What happens: For each NFS Write command the NFS daemon opens the file, writes the data received and release the file. When the FAT…
G. Bourreau
  • 11
  • 3
1
vote
1 answer

Calculation of exFAT checksum

I'm currently trying to format a disk to exFAT using a micro controller. My issue is that I need to calculate a checksum that uses the bytes from sector 1 to 11 of the VBR (Volume Boot Region) to store it into sector 12 but my result is incorrect.…
Arthur Penguin
  • 83
  • 1
  • 7
1
vote
1 answer

AVR FAT-driver design

Title might be misleading, however I felt unable to write an accurate one. My apologies. I'm working on a "partial" FAT32-driver for AVRs, written in C. I'm trying to write a function that would basically read 4 valid entries (skip LFNs and empty…
carazh
  • 11
  • 1
  • 2
1
vote
2 answers

File Allocation Table Reading

I am working on a custom FAT file system explorer and things have been going quite well. However, I want to know if there is a better way to efficiently read/write to the chainmap. For large devices, this can be incredible resource intensive and it…
Eaton
  • 1,310
  • 2
  • 15
  • 31
1
vote
1 answer

How are floppy disk sectors numbered

I was wondering how are floppy disk sectors ordered, I am currently writing a program to access the root directory of a floppy disk (fat12 formated High Density), I can load it with debug at sector 13h but in assembly it is at head 1 track 0 sector…
user4674223
1
vote
1 answer

Creating a fat jar for Dropwizard application

I am trying to create a fat jar for a multi module java project following the dropwizard documentation that makes use of the maven shade plugin. https://dropwizard.github.io/dropwizard/getting-started.html#building-fat-jars In order to do this I…
user_mda
  • 18,148
  • 27
  • 82
  • 145
1
vote
1 answer

Basic File System Implementation

I've been given 2k bytes to make a ultra minimalistic file system and I thought about making a stripped out version of FAT16. My only problem is understanding how do I store the FAT in the volume. Let's say I use 2 bytes per block hence I'd have…
Cristian Eduardo Lehuede Lyon
  • 1,937
  • 4
  • 22
  • 39
1
vote
2 answers

Using MCU's internal flash memory as FatFs drive

I'm trying to make internal flash on STM32F051xx to be seen as a drive. This is the code on the top level: char USER_Path[4]; /* USER logical drive path */ FATFS USER_FatFs; /* File system object for User logical drive */ FIL USER_File; /* File…
andrey
  • 1,515
  • 5
  • 23
  • 39
1
vote
0 answers

File allocation table (FAT8) implementation error in C++?

I am trying to simulate FAT8 File_Allocation_Table. FAT entries varies from -1 to 255 inclusive. Directory entry contains starting address of FAT table for a particular directory. Whenever the starting address is greater than 127 then it's give a…
user3182811
  • 115
  • 2
  • 9
1
vote
1 answer

Detecting FAT directory entries

While trying to data-recovery of a flash-drive, I am trying to write a tool that can search for FAT directory entries. Since I cannot rely on the FAT to tell me where to look, I am doing a simple scan of the drive sectors (actually an image dump of…
Synetech
  • 9,643
  • 9
  • 64
  • 96
1
vote
2 answers

Best way to handle a multi-task file system using an RTOS in embedded C?

I am using the CMX-RTX RTOS and Elm Chan FatFS. Things work well until tasks line up to hit the file system. For those familiar with Chan FatFS I have modified the ENTER_FS and LEAVE_FS macros to take and release a resource. If a task tries to enter…
Brad
  • 21
  • 4
1
vote
1 answer

Does the FAT filesystem have a signature?

Given the following BPB: FAT32 BPB http://img121.imageshack.us/img121/1131/fat32bpb.png The "MSWIN4.1" string is just the "OEM ID" field, and by Microsoft documentation it should not be used to identify FAT volumes. The "FAT32 " string is the…
DxCK
  • 4,402
  • 7
  • 50
  • 89
1
vote
0 answers

execute permissions on fuse/fat filesystem

've successfully cross compiled ruby for android and everything goes ok in the emulator. but while i'm testing these funny things on my device ( Nexus4 ) i noticed that /sdcard ( or /storage/emulated/0 ) is a fuse mount with no execution…
tux_mind
  • 306
  • 1
  • 5
  • 15
1
vote
3 answers

Why did Windows use the FAT structure instead of a conventional linked list with a next pointer for each data block of a file?

Instead of storing references to next nodes in a table, why couldn't it be just stored like a conventional linked list, that is, with a next pointer?
adijo
  • 1,450
  • 1
  • 14
  • 20
1
vote
2 answers

Getting next cluster number in FAT12

I am using BrokenThorn's tutorial for OS develpoment. My confusion is in this piece of code, which is responsible for reading the next cluster number of the file: mov ax, WORD [cluster] ; identify current cluster from FAT ; is the…
Cygnus
  • 3,222
  • 9
  • 35
  • 65
1 2 3
…
12 13