XON/XOFF is on ice. I decided to implement a FILE mode with a PACE character for performing a handshake with an uploader. Until I have a matching uploader, I'm using picocom with ascii-xfr (borrowed from minicom) with a long delay at the end of each line.

STM8EF is now very close to a self-contained development environment, and it's at the point of being an MVP (Minimal Viable Product).

The files on GitHub are up-to-date :-)