Quick post about what I needed to do to get Serial Over Lan (SOL) working on an HP z420 workstation. This machine has a Xeon processor. Sincce there's no integrated graphics, the KVM capaability of Intel vPro/AMT doesn't work.
Modify /etc/default/grub and add the following two lines at the end fo the file.
GRUB_CMDLINE_LINUX="console=tty0 console=ttyS4,115200n8"
GRUB_SERIAL_COMMAND="serial --speed=115200 --port=0xe060 --word=8 --parity=no --stop=1"
Create the file /etc/systemd/system/serial-getty@ttyS4.service with the following contents.
# This file is part of systemd.
#
# systemd is free software; you can redistribute it and/or modify it
# under the terms of the GNU Lesser General Public License as published by
# the Free Software Foundation; either version 2.1 of the License, or
# (at your option) any later version.
[Unit]
Description=Serial Getty on %I
Documentation=man:agetty(8) man:systemd-getty-generator(8)
Documentation=http://0pointer.de/blog/projects/serial-console.html
BindsTo=dev-%i.device
After=dev-%i.device systemd-user-sessions.service plymouth-quit-wait.service
After=rc-local.service
# If additional gettys are spawned during boot then we should make
# sure that this is synchronized before getty.target, even though
# getty.target didn't actually pull it in.
Before=getty.target
IgnoreOnIsolate=yes
[Service]
ExecStart=-/sbin/agetty --keep-baud 115200 %I vt100-nav
Type=idle
Restart=always
UtmpIdentifier=%I
TTYPath=/dev/%I
TTYReset=yes
TTYVHangup=yes
KillMode=process
IgnoreSIGPIPE=no
SendSIGHUP=yes
[Install]
WantedBy=getty.target
Enable the ttyS4 getty in systemctl with command below.
systemctl enable serial-getty@ttyS4.service
Reboot your machine. You should be able to use SOl via the following command. There will be a prompt for the AMT password. This was set in your BIOS.
amtterm host or ip address
Check the status of the getty
systemctl status serial-getty@ttyS4.service