In LILO's configuration file /etc/lilo.conf, you can configure the resolution for the VESA framebuffer that is used when Linux boots up. Resolutions are given as a predefined numerical code, instead of specifying the resolution directly. In order to find the code for the resolution you want, you can look at the LILO's configuration file for some examples.

However, this file contains only low resolutions, not fit for most modern laptops. But, you can take another approach to find your numerical code. You can ask LILO to display the available numerical codes for your machine by including the following line in LILO's configuration file:

vga = ask

Save LILO's configuration file and don't forget to run LILO:

$ lilo

Now, reboot your machine. At boot, LILO will display a table associating numerical codes with their corresponding resolutions. Remember the numerical code you choose because we will need to add it to LILO's configuration file later. For example, in my case, I use 1280x800x32k which has the numerical code 361. Therefore, I must change the previous vga option to 0x361, like so

vga = 0x361

because numerical codes, as displayed at boot time, are in hexadecimal base.

Tags: slackware