Run sudo vim /etc/default/grub from terminal
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.