Merge pull request #1 from cs-education/master

Pulling upstream changes
jor1k-master tty0/tty1 char I/O
Two terminal UI
almost working (?) dual terminal implementation using 2nd UART
working (manual) dual terminal support
some code cleanup
dual terminals complete
Fixed fullscreen bug and compiler bug
Merge branch 'dual' of https://github.com/wchill/sysbuild into wchill-dual
Merge branch 'wchill-dual'