nevermind, I found what my issue was, and in the process I learned how to use the JTAG debugger over USB with gdb and openocd, on this new target.
My sector size was wrong, I assumed some sort of cache existed to realign wl_flash to SD card sector size emulation, but it's not even needed than the ...

my bad for the double posting (new on this forum).
Update:

I did check in the IDF and the FFat arduino library indeed registers the low level implementations of diskio (disk_read, disk_write etc) in the esp_vfs_fat_spiflash_mount() function and calls ff_diskio_register_wl_partition(). Those are ...

Hello, I'm bumping this as I'm in the same boat : I'm trying to expose FFAT file system as a mass storage flash drive over USB.
I got the ram disk example working and I have implemented this on another MCU using tinyUSB, using FATFS too.

Here I understand the access to FATFS uses an interface that ...