On Fri, Jan 30, 2026 at 12:31:34PM +0000, Stuart Henderson wrote: > On 2026-01-30, Stuart McKim <[email protected]> wrote: > > I have a file server that does not have a serial port, only vga. Since > > it's normally headless, I'm trying to use a USB serial adapter to > > 1. login > > that should be possible > > > 2. display boot messages > > that will not be possible with a USB adapter
I was worried that might be the case. Is there a way to get kernel panic messages via serial in such a case without taking photos of the VGA console? That's the end goal, as I've been having lockups and until the last time I didn't have a display connected, but then that time I goobered it up while trying to take photos. > > The adapter shows up as: > > uftdi0 at uhub3 port 1 configuration 1 interface 0 "FTDI USB Serial > > Converter" rev 2.00/6.00 addr 2 > > ucom0 at uftdi0 portno 1: usb3.0.00001.0 > > > > I've been able to test that it's functional by connecting to it from my > > desktop, which has a serial port, using: > > cu -l /dev/cuaU0 > > And all is well. > > > > Starting with goal 1 (login): > > > > Trying to add the appropriate entry to /etc/ttys is where I am running > > into trouble. First I tried: > > ttyU0 "/usr/libexec/getty std.9600" vt220 on secure > > > > When hitting Enter on my desktop end, I get new lines, but no prompt. > > > > I changed the entry to: > > cuaU0 "/usr/libexec/getty std.9600" vt220 on secure > > > > Now I get a login prompt, but also receive the following error after > > logging in: > > ksh: No controlling tty (open /dev/tty: Device busy) > > ksh: warning: won't have full job control > > > > And it's not really a usable session since I don't have a tty. > > > > What am I doing wrong? > > It should be ttyU0 not cuaU0 in /etc/ttys. cua is just meant for > outbound connections, it allows sharing a single device with > tty for incoming connections - see tty(4) for info. That was my understanding based on the documentation, but posted what else I tried in case it was helpful. > It's possible some of the hardware lines aren't connected up, if so > and if it's difficult to fix, you could try with 'softcar' and see > if that gets you a login prompt? The following modification makes no change in behavior (new lines, but no login prompt): ttyU0 "/usr/libexec/getty std.9600" vt220 on secure softcar -- Stuart A. McKim, P.E. Idaho Falls, ID
