I agree the problem I have is that in project usb_host_msd_fatfs\freertos the fatfs library is implemented with usb_host and not device stack. In file "diskio.c", low-level function implement function like USB_HostMsdInitializeDisk, USB_HostMsdReadDisk, etc...
In my case, I want to create the file on a USB ramdisk like device. I see that some function are also implemented for that kind of application: ram_disk_read(pdrv, buff, sector, count), ram_disk_write(pdrv, buff, sector, count), ... but I don't find the reference to them in the project
Regards