> > It looks like I was indeed supposed to use cua, and I can now get a file > > descriptor. However, I'm still not able to set the baud rate, it's stuck > > at 19200 whether I try to set it with tty01 or cua01. cua00 corresponds > > with tty00, which is the serial console, so I shouldn't use that. > > I don't recall where this is documented, but terminal devices reset > their settings when the last fd open to them is closed.
Let's simplify that: All devices reset their settings when the last open to them is closed. It is entirely obvious. Otherwise, every application would have to have a ton of reset code in it. And that would be really stupid.

