FSKit - Documentation? Examples?

Found this msdos file system, but I wouldn't say it's extensively documented :)

Looking for any more documentation on FSKit - < > https://developer.apple.com/documentation/fskit?language=objc

Yes. FSKit has obviously been a major effort and the teams focus has been on getting the framework into the system. There is still plenty of supporting work to be done and that will take more time, but it's really exciting to be shipping a user space file system framework for the first time.

Attempted to try to put something together and immediately ran into failed at lookup with error 159 - Sandbox restriction

Speaking of details, this is another case of this. The framework itself has been heavily tested (case in point, it's how the current system supports FAT32), but that testing was obviously focused on the file systems included with the system.

The process of how a 3rd party file system would load is what's new and that's what's breaking down here. It's not clear at this point whether that's a configuration issue that you could correct or an issue with the sandbox profile in the system itself, but either way my recommendation would be to take a look at this again in a future seed. This is the kind off issue where you can waste a whole lot of time trying to figure out exactly what you're missing, but is trivial once Xcode includes it as a project template.

Found this msdos file system, but I wouldn't say it's extensively documented :)

It's not perfect, but I appreciate that the team was able to open source a working implementation of a "real" file system. FAT is a pretty good compromise between the complexity of a more modern file system (like APFS or the final versions of HFS+) and a "toy" file system that's only intended to be a demonstration.

-Kevin Elliott
DTS Engineer, CoreOS/Hardware