Tux Training

This is a comprehensive HOWTO to change your TTY (Ctrol+Alt+F1) and bootscreen resolution.  I am sure we have all noticed the low resolution used while Linux is booting up, and also of the TTY (Ctrol+Alt+F1). The resolution of the TTY is set as a paramater given to the kernel before it loads. GRUB is responsible for booting the kernel, so we need to tell GRUB to tell the kernel what resolution we want. GRUB’s list of boot options is contained in the file /boot/grub/menu.lst.

• Open up the Terminal by going to Applications -> Accessories -> Terminal
• Before you open up the file we should back it up.  Just type in the terminal:

  sudo cp /boot/grub/menu.lst /boot/grub/menu.lst~

  Enter your password when prompted. This will backup the file as menu.lst~.

• Now we open it up with:

   sudo vi /boot/grub/menu.lst

• Look for the line (or first instance of the line, this will vary from distro to distro)

   kernel         /boot/vmlinuz-2.6.15-25-686 root=/dev/sda2 ro quiet splash

• where 686 is your CPU archietecture such as 386, AMD64 or PPC, and /dev/sda2 is your hard drive partition such as /dev/hda1.
• This is the command for your kernel, and we need to ammend a paramater to tell the kernel to boot into a certain resolution. This is done with the vga= flag, along with a special number for your desired screen resolution and color depth.

  Refer to the following table to see what your resolution’s number is:

  	640×480	800×600	1024×768	1280×1024	1600×1200
  8bit	769	771	773	775	777
  15bit	784	787	790	793	796
  16bit	785	788	791	794	797
  24bit	786	789	792	795	798

  You will most likely want the 24bit color depth (AKA “True Color”) (choose this if you are not sure) along with a desent resolution such as 1024×768 or 1280×1024. I, for example, want 24bit with 1280×1024 so I choose 795, and will ammend vga=795 to the line, giving me:

  kernel          /boot/vmlinuz-2.6.15-25-686 root=/dev/sda2 ro quiet splash vga=795

  Go ahead and ammend vga= to the kernel line in menu.lst along with your screen resolution number form the table above, like in the example.

• Save the file. (If you can’t save the file you haven’t opened it as root, go back and execute gksudo gedit /boot/grub/menu.lst providing your password.)
• Restart your computer.
• If your computer dies on boot, get into recovery mode and replace the menu.lst file with the backup one with:

  sudo cp /boot/grub/menu.lst~ /boot/grub/menu.lst

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Tags: menu.lst, tty resolution

This entry was posted on Friday, May 16th, 2008 at 10:55 am and is filed under Hardware, Tweaks. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.