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I have a laptop with a broken screen and I am using it as a home server. So I would like to install Devuan GNU/Linux on it by using a serial console.

I have a null-modem serial cable and I have successfully used it to connect to the serial console of a raspberry-pi (running FreeBSD) from another Linux laptop by using the screen command.

So, now I was hoping that the Devuan installation DVD would automatically set up a serial console and that I could access it from the other laptop as I did with the rpi. Unfortunately this is not the case: on the other laptop I have a black screen.

On the rpi I have a serial adapter card. On the screenless laptop I have a USB/serial adapter.

So: is it possible to run a Devuan installation over a serial console? Do I need to modify the installation image or pass it any special parameters to tell it that it should use the serial console?

EDIT

I have made some progress but have not solved the problem yet. I have been testing on a desktop that has a serial port, so I can use it without USB adapter. My plan is to get the console working on a running system and then try and apply the needed changes to the installation image.

I got the kernel logging on the serial console by using the kernel parameter console=ttyS0,115200. I have managed to have the grub menu on the serial console by adding

serial --speed=115200 --unit=0 --word=8 --parity=no --stop=1
terminal_input --append serial
terminal_output --append serial

at the end of /etc/grub.d/40_custom

I also got a login console by editing /etc/inittab and adding an entry for ttyS0.

Now I am stuck at the next step. The computer I want to use as a server does not have a serial port so I have to use a USB serial adapter. The USB adapter shows up as /dev/ttyUSB0 on a running system.

If I define a console in /etc/inittab for ttyUSB0 I get a serial console.

If I change the kernel parameter to console=ttyUSB0,115200 I get no kernel logging on the serial console. I suppose this is because the kernel does not have the module usbserial which is needed by the USB/serial adapter. My next attempt will be to compile a kernel with the module built-in.

Regarding the GRUB2 menu, I still have open issues:

  1. What value should I specify for the --unit= parameter: ttyS0 gets mapped to --unit=0, what about ttyUSB0?
  2. Does grub need to load some kind of module in order to use the USB adapter properly?

EDIT 2

I found some interesting help here. In particular, I did the following:

when you get the initial boot menu, just press "TAB" to edit the boot command and simply add "console=ttyS0,115200u8" to the end of the default boot command.

This brought me to an installer running on the serial console on a PC that has a serial port. So it seems I am almost there.

I then tried using the serial adapter on USB on the same PC and the option console=ttyUSB0,115200u8 on the kernel line. This leads to a black screen and no serial console.

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