Fedora 27: GRUB2 and Linux with serial console

Table of Contents

1 /etc/default/grub

Change /etc/default/grub as below.

  • Change GRUB terminal to console and ttyS0. This will provide one GRUB to a monitor display and serial console.
  • Change linux kernel console to tty1 and ttyS0. This setting will be taken over to userland, and there will be two login prompt for tty1 and ttyS0.

$ cat /etc/default/grubGRUB_DEFAULT=0GRUB_TIMEOUT=1GRUB_DISTRIBUTOR=$(sed “s, release .*$,,g” /etc/system-release)GRUB_DISABLE_SUBMENU=trueGRUB_CMDLINE_LINUX=”rd.lvm.lv=fedora/root rd.lvm.lv=fedora/swap”GRUB_CMDLINE_LINUX_DEFAULT=”console=tty1 console=ttyS0,115200″GRUB_TERMINAL=”console serial”GRUB_SERIAL_COMMAND=”serial –speed=115200 –unit=0 –word=8 –parity=no –stop=1″GRUB_DISABLE_RECOVERY=”true”

2 grub2-mkconfig

Update /boot/grub2/grub.cfg with grub2-mkconfig.

$ sudo grub2-mkconfig -o /boot/grub2/grub.cfgGenerating grub configuration file …Found linux image: /boot/vmlinuz-4.13.9-300.fc27.x86_64Found initrd image: /boot/initramfs-4.13.9-300.fc27.x86_64.imgFound linux image: /boot/vmlinuz-0-rescue-55e8571f1d954b0d81bcf12ff2fd4c64Found initrd image: /boot/initramfs-0-rescue-55e8571f1d954b0d81bcf12ff2fd4c64.imgdone

Reboot system.

$ sudo reboot

3 Execution result

GRUB to monitor display is as below.


GRUB to serial console is as below. This article used “sudo virsh console <vmname>” for connecting serial console.


Login prompt to monitor display is as below. tty1 is displayed with press Ctrl + Alt + F1.


Login prompt to serial console is as below.


Android | Linux | SDL - Narrow Escape