PrFILE®2 exFAT overview

PrFILE2 exFAT is a file system that supports FAT12/16/32, and exFAT for embedded systems. exFAT is optimized for large-capacity storage media exceeding 32 GB, such as flash memory cards, USB flash drives, and external hard drives, using the file system specifications developed by Microsoft.
PrFILE2 exFAT enables the high-speed handling of large-sized files, such as video, audio and photos, that are stored on large-capacity media. This file system is optimal for systems that use large amounts of high-quality image or audio data, such as portable music or media players, digital cameras or video players, high definition digital TVs, photo printers, photo frames, or surveillance cameras.
PrFILE2 exFAT was developed based on PrFILE2. All the features of PrFILE2 are inherited.

Optimized for large-capacity media and large files

This file system is optimized for large-capacity storage media exceeding 32 GB, such as flash memory cards, USB flash drives, and external hard drives. Files exceeding 4 GB can be used, which was not possible in the conventional FAT32 file system. It supports 2TB or more exFAT partition and can read/write 2TB or more files.

Optimized free cluster search and file deletion

A free cluster bitmap image stored within the system is used to search at high speed for free clusters in the media. In addition, files are deleted when the free cluster bitmap image is updated, which enables the high-speed deletion even of large files.

Unicode used as the character code for file name specification

Unicode is used as the universal character code for file names in the exFAT file system, eliminating the need to support different character codes according to the language of the country or region.

High-speed operation with a small memory footprint

PrFILE2 exFAT was developed based on PrFILE2 not as an add-on to PrFILE2, but by optimizing the functions and performance as an exFAT file system. This results in a small memory footprint. Large files can also be operated at high speed.

Inherited functions and features of PrFILE2

PrFILE2 exFAT has inherited all the features of PrFILE2. These include functions and features useful for digital media devices, such as a high-speed seek back function for the file pointer, and a function for minimizing file system damage in the event of power shutoff or media removal.

Also functions as a FAT12/16/32 file system

PrFILE2 exFAT functions not only as an exFAT file system, but also as a FAT12/16/32 file system according to the format of the target media. For example, if the media format is FAT32, then the system operates as a FAT32 file system. The file name can be specified from the application in Unicode even when PrFILE2 exFAT operates as a FAT12/16/32 file system.

Supports large-capacity devices (exceeding 2 TB)

Supports GUID Partition Table (GPT) (currently under development).

Optional drivers available

The following drivers are provided as options:

• SD Memory Card
  *This device driver is for SD memory cards (SD/SDHC/SDXC) and MultiMediaCards (MMC)

Supports T-Kernel

PrFILE2 exFAT supports T-Kernel.

High portability

PrFILE2 exFAT itself is written in the C language and is not dependent on any CPU. Device drivers and code dependent on the operating system are separated to ensure easy porting to a different environment. The file system can even operate in an environment without an operating system.

Source code provided

PrFILE2 exFAT is provided as source code.

Maintenance service and customization service

The following maintenance service is provided. The maintenance service enables developers to use PrFILE2 exFAT with peace of mind.

• Response to email inquiries regarding the product
• Minor version upgrades

In addition, a customization service is available for supporting PrFILE2 exFAT in different environments, such as a custom real-time operating system or hardware.

Operating environment

PrFILE2 exFAT is not dependent on any particular hardware or operating system. Successful operation has been demonstrated on the following operating systems:

• eSOL's eMCOS® POSIX
• eSOL's eT-Kernel™ (extended T-Kernel)

Support LP64：It is possible to build and operate in 64bit CPU environment.

Optional products

SD Memory Card Driver

This device driver for PrFILE2 is a device driver for SD memory cards (SD/SDHC/SDXC) and MultiMediaCards (MMC).

PrFILE2 exFAT FAT Safe

This optional product for PrFILE2 provides a recovery function in case an inconsistency occurs in the file system, such as after an unexpected power shutoff or media removal.

Use Case

• Nintendo Switch Lite [Game Console]