Microsoft Wants exFAT in Linux Kernel, Opens File System Specs

Microsoft announced today that it supports the inclusion of its exFAT (Extended File Allocation Table) file system for USB flash drives and SD cards in the Linux kernel through the Open Invention Network.

"Today we’re pleased to announce that Microsoft is supporting the addition of Microsoft’s exFAT technology to the Linux kernel," said John Gossman, Microsoft Distinguished Engineer, and Linux Foundation Board Member.

The proprietary exFAT tech was introduced more than a decade ago in 2006 as the successor to FAT32 in the FAT family of file systems and it is now used by the vast majority of flash memory storage devices.

Although a free and FUSE-based exFAT implementation is available for Linux users who want to mount exFAT-formatted SD cards and flash drives on their computers, this driver still strives to provide a full-featured implementation.

Announcing support for exFAT in the #Linux kernel. Learn more: https://t.co/4H80Qc7XzT 

— Open at Microsoft (@OpenAtMicrosoft) August 28, 2019

exFAT Linux code to be available under GPLv2

In preparation for a future Linux kernel with exFAT support, Microsft published the exFAT technical specification on its Windows Dev Center website.

Redmond also said that they "are making the technical specification for exFAT freely available to all, and exFAT code incorporated into the Linux kernel will be available under GPLv2."

"It’s important to us that the Linux community can make use of exFAT included in the Linux kernel with confidence," added Gossman.

"To this end, we will be making Microsoft’s technical specification for exFAT publicly available to facilitate development of conformant, interoperable implementations."

The Linux Foundation is pleased to see Microsoft’s open source evolution extending to support inclusion of exFAT in both the Linux® kernel and the Open Invention Network’s Linux System Definition. https://t.co/DAMOUCzZUs

— The Linux Foundation (@linuxfoundation) August 28, 2019

"We also support the eventual inclusion of a Linux kernel with exFAT support in a future revision of the Open Invention Network’s Linux System Definition, where, once accepted, the code will benefit from the defensive patent commitments of OIN’s 3040+ members and licensees."

Microsoft's open-source journey

Microsoft joined The Linux Foundation as a platinum member in November 2016 after slowly embracing the open-source software model after Satya Nadella took over as the company's CEO.

Previously, Redmond had open-sourced various other core technologies and tools or core behind some of its proprietary tech including but not limited to the .NET compiler, Edge's JavaScript engine, TypeScript, and Xamarin.

Microsoft also developed the Windows Subsystem for Linux (WSL), a compatibility layer that makes it possible for users of Windows 10 and Windows Server 2019 to natively run Linux binaries in ELF format on their computers.

Even more recently, Redmond's developers have started working on WSL2 which uses a genuine open-source kernel compiled from the stable 4.19 version release of Linux at Kernel.org, thus making it no longer needed to use a translation layer between apps and their system calls.