SDCardFS provides POSIX-like semantics on top of a FAT32/exFAT-formatted SD card.

[[https://www.xda-developers.com/diving-into-sdcardfs-how-googles-fuse-replacement-will-reduce-io-overhead/|Diving into SDCardFS: How Google's FUSE replacement will reduce I/O overhead]]

[[https://android.googlesource.com/kernel/common/+/refs/heads/android-4.19-q-release/fs/sdcardfs/file.c|fs/sdcardfs/file.c]] for Linux 4.19 (Q)