Ask Ubuntu is a question and answer site for Ubuntu users and developers. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

How do I invoke the kernel with serial console on 12.04?

In 10.04 I could just add console=ttyS0 in kernel line or install quiet console=ttyS0 on boot: line

How do I do that in 12.04?

share|improve this question

There is nothing special in 12.04. Just follow the information from:

1) Paste the following into /etc/init/ttyS0.conf

# ttyS0 - getty
# This service maintains a getty on ttyS0 from the point the system is
# started until it is shut down again.

start on stopped rc or RUNLEVEL=[2345]
stop on runlevel [!2345]

exec /sbin/getty -L 9600 ttyS0 vt102

2) Ask upstart to start the getty

sudo start ttyS0

This will get you access to console. To get access to Linux init console, configure grub.

1) Edit /etc/default/grub to contain the following lines

GRUB_CMDLINE_LINUX="console=tty1 console=ttyS0,9600n8"
GRUB_SERIAL_COMMAND="serial --speed=9600 --unit=0 --word=8 --parity=no --stop=1"

2) update grub

sudo update-grub

I am using 9600 just because I am using a server where the BIOS is already redirected over seria using 9600. If you don't care about the BIOS settings, feel free to use a faster serial line.


share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.