How do I add a kernel boot parameter?

Question

I need to add the boot parameter foo=bar to my kernel. How can I do this once for testing, and permanently if testing was a success?

score 367 · Accepted Answer · edited Jul 25 '24 at 11:45

To temporarily add a boot parameter to a kernel

Start your system and wait for the GRUB menu to show (if you don't see a GRUB menu, press and hold the Left Shift key right after starting the system).
Now highlight the kernel you want to use, and press the e key. You should be able to see and edit the commands associated with the highlighted kernel.
Go down to the line starting with linux and add your parameter foo=bar to its end.
Now press Ctrl+x to boot.

To make this change permanent

From a terminal (or after pressing Alt+F2) run:
```
gksudo gedit /etc/default/grub
```
(or use sudo nano if gksudo or gedit are not available) and enter your password.
Find the line starting with GRUB_CMDLINE_LINUX_DEFAULT and append foo=bar to its end. For example:
```
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash foo=bar"
```
Save the file and close the editor.
Finally, start a terminal and run:
```
sudo update-grub
```
to update GRUB's configuration file (you probably need to enter your password).

On the next reboot, the kernel should be started with the boot parameter. To permanently remove it, simply remove the parameter from GRUB_CMDLINE_LINUX_DEFAULT and run sudo update-grub again.

To verify your changes, you can see exactly what parameters your kernel booted with by executing cat /proc/cmdline.

Wiki page.

score 19 · Answer 2 · answered Jul 05 '12 at 21:25

19

To add any kernel option:

for a liveCD session: follow these steps
for an Existing Installation: use Boot-Repair's Add a kernel option or Edit GRUB configuration file options.

enter image description here

See also this documentation.

answered Jul 05 '12 at 21:25

LovinBuntu

3,785

score 14 · Answer 3 · edited May 19 '18 at 08:33

14

Alternatively, you may also use the handy grub-customizer:

sudo add-apt-repository ppa:danielrichter2007/grub-customizer
sudo apt-get update
sudo apt-get install grub-customizer
gksu grub-customizer &

Just open a boot entry, and edit its kernel parameters as highlighted in the screenshot below:

edited May 19 '18 at 08:33

David Foerster

36,890
56
97
151

answered Dec 11 '12 at 01:59

jasxun

396

How do I add a kernel boot parameter?

3 Answers3

To temporarily add a boot parameter to a kernel

To make this change permanent

Linked

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