How to set NOMODESET and other kernel boot options in grub2

On some hardware configurations, you need to set some kernel parameters for ubuntu to boot or work properly. A common one is nomodeset, which is needed for some graphic cards that otherwise boot in to a black screen or corrupted splash, acpi_osi= to fix lcd backlight and other problems, and noapic and nolapic to work around various ACPI BIOS issues. In this how to I will explain briefly what this is and how to do it.

This how to applies to ubuntu 10.04 and 10.10. It may not apply to wubi, I dont know how to do it in wubi. (update, see post #8 for the differences with wubi)

What are these options?

nomodeset

The newest kernels have moved the video mode setting into the kernel. So all the programming of the hardware specific clock rates and registers on the video card happen in the kernel rather than in the X driver when the X server starts.. This makes it possible to have high resolution nice looking splash (boot) screens and flicker free transitions from boot splash to login screen. Unfortunately, on some cards this doesnt work properly and you end up with a black screen. Adding the nomodeset parameter instructs the kernel to not load video drivers and use BIOS modes instead until X is loaded.

Note that this option is sometimes needed for nVidia cards when using the default "nouveau" drivers. Installing proprietary nvidia drivers usually makes this option no longer necessary, so it may not be needed to make this option permanent, just for one boot until you installed the nvidia drivers.

continue reading