I can answer the "is there an easy way to integrate said filesystem into musllibc such that one could use the
standard open/read/write/close functions"?
The answer is yes ;). Take a look at libsel4camkes  which already binds some of the common C library functions. You could extend these for some subset of file descriptors that identifies your file system, or base an implementation on the code in this
From: Devel <email@example.com> on behalf of Grant Jurgensen <firstname.lastname@example.org>
Sent: Tuesday, 24 July 2018 2:44 AM
Subject: [seL4] Implementing a Filesystem on CAmkES
I was hoping to get some advice on how to implement a filesystem on my CAmkES project. For now I'm targeting FAT32, but that is flexible. So far, my plan is to port the libsdhcdriver to my platform (which shouldn't be too bad. I'm targeting exynos5, and I see
exynos4 is already supported). After that, I assume I'm on my own when it comes to creating a filesystem interface. Perhaps there is an existing library for this that can hook into any standard SD controller implementation? Finally, is there an easy way to
integrate said filesystem into musllibc such that one could use the standard open/read/write/close functions?
Does this sound like the best way to go, or am I missing a simpler solution?