Microsoft announces its support for bringing exFAT in the Linux kernel; open sources technical specs

Yesterday, Microsoft announced that it supports the addition of its Extended File Allocation Table (exFAT) file system in the Linux kernel and publicly released its technical specifications.

https://twitter.com/OpenAtMicrosoft/status/1166742237629308928

Launched in 2006, the exFAT file system is the successor to Microsoft's FAT and FAT32 file systems that are widely used in a majority of flash memory storage devices such as USB drives and SD cards. It uses 64-bits to describe file size and allows for clusters as large as 32MB. As per the specification, it was implemented with simplicity and extensibility in mind.

John Gossman, Microsoft Distinguished Engineer, and Linux Foundation Board Member wrote in the announcement, “exFAT is the Microsoft-developed file system that’s used in Windows and in many types of storage devices like SD cards and USB flash drives. It’s why hundreds of millions of storage devices that are formatted using exFAT “just work” when you plug them into your laptop, camera, and car.”

As exFAT was proprietary previously, mounting these flash drives and cards on Linux machines required installing additional software such as FUSE-based exFAT implementation. Supporting exFAT in the Linux kernel will provide users its full-featured implementation and can also be more performant as compared to the FUSE implementation. Also, its inclusion in OIN's Linux System Definition will allow its cross-licensing in a royalty-free manner. Microsoft shared that the exFAT code incorporated into the Linux kernel will be licensed under GPLv2.

https://twitter.com/OpenAtMicrosoft/status/1166773276166828033

In addition to supporting exFAT in the Linux kernel, Microsoft also hopes that its specifications become a part of the Open Invention Network’s (OIN) Linux definition. Keith Bergelt, OIN's CEO, told ZDNet, "We're happy and heartened to see that Microsoft is continuing to support software freedom. They are giving up the patent levers to create revenue at the expense of the community. This is another step of Microsoft's transformation in showing it's truly committed to Linux and open source." The next edition of the Linux System Definition is expected to publish in the first quarter of 2020, post which any member of the OIN will be able to use exFAT without paying a patent royalty.

The Linux Foundation also appreciated Microsoft's move to bring exFAT in the Linux kernel:

https://twitter.com/linuxfoundation/status/1166744195199115264

Other developers also shared their excitement. A Hacker News user commented, “OMG, I can't believe we finally have a cross-platform read/write disk format. At last. No more Fuse. I just need to know when it will be available for my Raspberry Pi.”

Read the official announcement by Microsoft to know more in detail.