STM32 CubeFx FatFs update to support exFAT

bobaruni · ‎2016-11-15

Posted on November 15, 2016 at 16:08

Hi, Chan has updated FatFs to version 0.12B but the bundled FatFs in CubeF0-F7 are all sitting on v0.11.

The reason I want to update to 0.12B is because of exFAT support for USB Flash memory.

I have tried to work out what changes were made to the original Chan FatFs library to port it over to STM32 MSC but it seems the ST implementation is based on some other sub branch somewhere between version 0.10C an 0.11 bot not exactly any of these.

Does ST Plan to update the bundled FatFs library?

If not, what where the steps involved in creating the ST version of the library in terms of what was the source code used for the starting point and what modifications were made?

Any help on this would be greatly appreciated.

Regards,

Bob.

Tesla DeLorean · ‎2016-11-15

Posted on November 15, 2016 at 19:36

Historically most of the platform specific portions of FatFs have been in the DISKIO.C file, where it reads/writes blocks/sectors to the underlying media.

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valentin · ‎2017-01-09

Posted on January 10, 2017 at 02:49

As I just came here because I had the same question:

Does that mean I can overwrite the provided FatFS files with the new ones from elm-chan and manually implement the ST drivers for my SD card?

Has anybody done this successfully?

Gabriele Caletti · ‎2017-03-14

Posted on March 14, 2017 at 16:31

I actually have the same problem. I tested the 0.12c version supporting the exFAT filesystem and it seems to work fine.

The problem is the licencing, exFAT must be licenced by Microsoft and I'm quite sure it's not for free...

Are you aware of any ST-Microsoft agreement about that?

Nemui Trinomius · ‎2017-03-14

Posted on March 15, 2017 at 01:39

Dear Valentin,

I migrated FatFs v0.12c with latest patch on CubeF7v1.6.0 and works fine.

Just swap older one for newer one(may be little change need on ffconf.h).

Best Regards,

Nemui.

Nor Sch · ‎2017-03-16

Posted on March 16, 2017 at 12:04

Integration of newer FatFS-Versions is not a Problem, yes.

But the Hint to the Licence is really important for commercial or in other Way distributed Products. You can disable the exFAT-Support in the File ffconf.h with

#define _FS_EXFAT 0�?�?�?

keep it at 0

This should solve the Licence-Problem ... or not? In optimized Code the exFAT-Parts should be not compiled in. In not optimized Code they (maybe) compiled in but not used. So I'm not really sure about a possible Infringement.

Gabriele Caletti · ‎2017-03-16

Posted on March 16, 2017 at 13:29

>This should solve the Licence-Problem ... or not?

It should, in fact the FatFS website (

http://elm-chan.org

) indicates this:

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Note that the exFAT is a patent of Microsoft Corporation. The exFAT function of FatFs is an implementation based on US. Pat. App. Pub. No. 2009/0164440 A1. FatFs module can swich the exFAT on/off by configuration option. When enable the exFAT on the commercial products, you will need to be licensed by Microsoft depends on the final destination of the products.

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