Both Virtual Terminal and USB ACM/CDC are implemented as TTYs, but for now, we haven't input mode control. VTs are more or less in Cooked mode, and USB is a pure RAW mode. As a consequence, a read() on USB TTY return only when the total lenght queried is read, and not after a new-line. We should implement a relatively generic interface to handle input/output from any TTY and manage echo, line editing, special characters, etc... outside the specific TTY implementation. Some documentation about these input mode [here](http://www.lafn.org/~dave/linux/terminalIO.html), or on [Wikipedia](http://en.wikipedia.org/wiki/Seventh_Edition_Unix_terminal_interface).