Adding a separate USB-Serial console to SG-2440 - /etc/ttys woes?

Strider3000

Running 2.4 Beta on official SG-2440 hardware.

Netgate SG-2440 hardware comes with a built-in USB console for debugging.
I'm trying to add a separate "physical" serial port console to the SG-2440, mainly for the purposes of "cheap" out of band debugging from devices that support physical serial redirect function, such as some Cradlepoint routers, SpiderDuo KVM (etc).
I got a suggestion to try using an FTDI-based USB to serial adapter: http://a.co/56uzg9F
When plugged into a SG-2440 USB port, pfSense "sees" it as a serial adapter /dev/cuaU0, and I can send and receive data by running "cu -l /dev/cuaU0 -s 9600" from pfSense command-line. So far so good.
I added uftdi_load="yes" to /boot/loader.conf, and after a reboot I can send and receive data via /dev/ttyU0 by running "screen /dev/ttyU0 115200". Not sure editing /boot/loader.conf is necessary, but again it seems to work fine.

Now I want to turn /dev/ttyU0 into a console port that I can use to access pfSense CLI.
From what I've read (http://www.plugged.in/linux/linux_help/serial-console-redirection-in-pfsense.html), this should be possible. However, any changes I make to the /etc/ttys file seem to be overwritten after boot.
For instance, if I add the following to /etc/ttys:

ttyU0 "/usr/libexec/getty Pc" vt100 on secure

It gets overwritten with this on the next boot:

ttyU0 "/usr/libexec/getty al.3wire" vt100 onifconsole secure

At this point I'm still able to send/receive data on ttyU0 by connecting from pfSense command line, but this isn't what I want to do. I want to be able to access the physical serial end and have it be a command-line interface to pfSense.

Am I going about this wrong? Is adding another serial console to the SG-2440 impossible to do, or does FreeBSD have issues with creating console ports out of serial-USB devices? Any thoughts or suggestions are appreciated.

n3by

Like you I wanted to have serial console for out of band management and I succeed to assign serial console to AMT instead of local COM port. The only disadvantage is that I lost local serial console from COM port…. not a big problem if computer have a VGA port.

If you want to have other adapter assigned to serial console you have to edit:
/boot/loader.conf.local

with your COM settings:
comconsole_speed="115200"
comconsole_port="0xPORT"

or with device:
#Determine this value from the pciconf -l
comconsole_pcidev=”0:3:3″

thanks to Derelict you can have a look here:
https://forum.pfsense.org/index.php?topic=132860.msg730615#msg730615

and here for AMT related:
http://blog.ignoranthack.me/?p=51

and freebsd doc:
https://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/serialconsole-setup.html

jimp

You can't add a USB serial adapter as a console, at least not that I've ever seen work. The USB device is not present early enough for it to be viable as a console for debugging purposes. It's a path that only leads to anger, heartache, and disappointment.

You can turn a cheap rpi or similar into a network/OOB USB serial console mux/server that connects to loads of other USB serial consoles quickly and easily with off the shelf hardware and without modding anything. Just USB hub(s) and such.