Consider using trackdisk.device. This would ensure it works with whatever device has been built into the Amiga. I have an old interactive shell that lets you put files on disk in its own filesystem. I used it for a 1994
music-disk which was written in Amos and had its trackload written in Basic. You can have the system, if you want. You would only need to write a confirming bootloader for the given file-structure which should be doable.