Hopper on Teensy 4.1 - first steps ..

The Hopper Portable Runtime is now running on the Teensy 4.1
I need a bit of help figuring out how to get LittleFS or some other file library working on the Teensy to finish implementing the Hopper file system.
Also need help getting attachInterruptParam(..) working.
Volunteers with more Teensy experience than me?
- SD card support
- attachInterruptParam(..)
- timer APIs
Hopper Arduino code on GitHub:
github.com/sil...
Teensy:
www.pjrc.com/t...