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Flash file system

 

Article updated at 19 Jun 2019
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The Flash File System is the part of the file system on the Colibri module which does not lose its data when you power off the module. It is a transaction safe file system (TFAT) which means data can not get corrupt in case of a sudden power loss.

Name

The folder on the Colibri device is called:

  • \NOR Flash on Win CE Images older than image version 3.0 on Colibri PXAxxx modules
  • \FlashDisk on all other systems

You can change the name of the folder in the registry. Please test your final setup if you change the folder name. For example, \Flashdisk\System is in the system search path. After renaming this folder will be in the object store (RAM).
On the Tegra Modules changing the folder name is supported in WinCe image V2.0 and later

[HKLM/System/StorageManager/Profiles/MSFlash] ; PXA
 Folder="DiskName_XY"
[HKLM/System/StorageManager/Profiles/Flashdisk] ; T20 / T30
 Folder="DiskName_XY"

Format

Format internal Flash File System

  1. To format the Flash File System go to Start->Settings->Control Panel->Storage Manager
  2. Dismount the partition
  3. Format
  4. New
  5. Type any partition name (it has no effect)
  6. Finish

Internal Flash is formatted with TFAT if not configured differently in the StorageManger profile [HKLM/System/StorageManager/Profiles/XYZ/FATFS] FormatTfat.

Format external storage device with TFAT

Windows CE supports transaction save FAT (TFAT). In order to format a external sotrage device (USB Memory, SD Memory Card, ...) using TFAT, perform the following steps.

  1. To format the Flash File System go to Start->Settings->Control Panel->Storage Manager
  2. Click on Properties
  3. Click Dismount
  4. Click Format
  5. Select TFAT flag and press start

You can use the APIs of the Windows CE Storage Manager as well: OpenStore(..), FormatPartition(..), etc.

If you want to create multiple partitions proceed the steps above twice but make sure you remove the tick at Use All Available Disk Space for the first partition and define the size of the partition manually. Otherwise you get an error message Unable to create partition.

You may also have a look at our Video Tutorials about the flash file system

Registry Settings Colibri PXAxxx

Windows CE Flash File System registry key location:

[HKEY_LOCAL_MACHINE\Drivers\BlockDevice\StrataFMD]
"MemLen"=dword:0          ;if this value is 0 (zero) (for the Colibri PXA270 "-1") the system uses all free flash memory as FlashFile system 
"MemBase"=dword:1980000   ;base address

Another option for changing the position and size of the Flash File System is to use the Colibri Tweak tool.

Registry Settings for Colibri T20 Modules

Note: On the current image version (1.4) these settings can not be done in the default image, but only if build your own image.

[HKEY_LOCAL_MACHINE\BuiltIn\NAND]
"FlushTimeout"=dword:500          ;default 500ms, if there is no Flash activity for FlushTime the System makes a flush.
"FlushMaxTransactions"=dword:120  ;default 120, if the timeout was not reached "FlushMaxTransactions" times the system makes a flush anyway