For linux mint you can edit /etc/default/grub
, look for the line that matches:
Add your options, for example:
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash vga=792"
Then simply run:
linux /boot/vmlinuz-2.6.32-21-generic root (lots of numbers) quiet splash
...you can add options to the end of that (it is the kernel line), however when your kernel is updated by the package manager you will lose the settings if they are placed in here, if you want it to be persistant then edit the /etc/grub/default file.