This is an MIT-licensed exFAT implementation for Arduinos. Maybe it can be adapted?
https://github.com/greiman/SdFat-beta -adam On Wed, Sep 2, 2020 at 9:53 PM Pelle Windestam < pelle.windes...@tagmaster.com> wrote: > > > > Hi everyone, > > > > > > Is there any support for high capacity SD-cards in NuttX, i.e. larger > > > than 32GB? I have done some research online and it seems that for > > > those sizes, SDXC cards using the exFAT file system is required. I > > > have looked through the code and cannot find anything indicating > > > support for either SDXC or exFAT. But I thought I would check in with > > > you guys in case I am missing something. > > > > > > > AFAIK there is not support to SDXC neither exFAT on NuttX. Although there > > exist exFAT support on Linux kernel introduced around version 5.4, I > think > > exFAT is covered by Patents, so it could be an issue. It appears you > need to > > be part of OIN (Open Invention Network) to get rid of patent issues: > > > > > https://www.techradar.com/news/microsoft-is-bringing-its-exfat-patents-to- > > linux-and-open-source > > > > So, instead of discussing how you could implement it, I want to asked > > you: "Why do you want SDXC and exFAT at first place?" > > The reason for asking about this is that we had customers who tried to use > 32GB+ SD-cards in our products, and they wondered why it was not working. > So, this is just an investigation from my side what our capabilities are. > We never tested with such large SD-cards ourselves. > > > Perhaps you could say you want a low cost and big storage solution. > > > > If this is the case, take a look at eMMC option. Ivan from Barin Sports > used > > this solution in their product and I think it better option for big > storage, > > low cost and will avoid you facing some issues with the Microsoft in the > > future. > > > > BTW, if you still thinking about exFAT on NuttX, you should implement it > > following the specification > > ( > https://docs.microsoft.com/en-us/windows/win32/fileio/exfat-specification) > > or if you don't have issue releasing all your company code as GPL, you > can > > port the exfat-linux project: > > > > https://github.com/arter97/exfat-linux > > > I do not think we will go that path right now, but it would be nice to > have the support of course so you could throw pretty much any SD-card into > the game without thinking about such compatibility issues. Something for > the long TODO-in-the-future list! > > //Pelle > -- Adam Feuer <a...@starcat.io>
