Must create directory for fatfs mount point?

[pahindman]

I'm wondering if the behavior I'm seeing with FAT is expected, or an indicator that I'm doing something wrong or am missing a config option. I'm using FAT with an eMMC and I can successfully mount a new FAT filesystem, but I can't actually use it until I make a directory that matches the name of the mount point. For example, using the fs shell command:

uart:~$ fs pwd
/
uart:~$ fs ls
uart:~$ fs mount fat /fat1
Successfully mounted fat fs:/fat1
uart:~$ fs ls
fat1/
uart:~$ fs cd fat1
/fat1 doesn't exist

Once I create that directory I can use it like I would expect:

uart:~$ fs mkdir fat1
uart:~$ fs ls
fat1/
uart:~$ fs cd fat1
uart:~$ fs pwd
/fat1
uart:~$ fs write phil.bin 44 55 66
uart:~$ fs read phil.bin
File size: 3
00000000  44 55 66                                         DUf

On the other hand, littlefs doesn't require creating that directory.

uart:~$ fs mount littlefs /lfs
Successfully mounted fat fs:/lfs
uart:~$ fs cd lfs
uart:~$ 

I've dug into it enough that I think this is just a consequence of how the fatfs vs littlefs modules are implemented, but I'm certainly not an expert and would be happy to be corrected. If that's just how it works then creating that directory isn't a big deal, I just want to make sure I'm not missing something obvious.

[sprhawk]

Thanks for your post, if not, I will waste more days to make it work. I can confirm it on zephyr 4.4.0.