Grub2 915resolution Patch

This was a patch I created based upon 915resolution. It allows you to rewrite existing vbios resolutions w/ resolutions of your choice (ex:/ 800x480 for the EeePC 701, or 1024x600 for newer netbooks, or perhaps widescreen resolutions). After the release of Xorg 7.5, this workaround will no longer be required thanks to the development of Kernel Mode Setting (KMS). It will only work with 800-900 series Intel Graphics Chipset. (Note that this patch supports G965 thanks to a patch supplied by Scot Doyle, 915resolution does not support this chipset).

Installation

Downloads:

Requirements:

Ruby (To reconfigure the build system, otherwise 915resolution will not get built

Untar the grub tarball, and apply the patch

patch -Np1 -i ../grub-1.96-915resolution.patch

Compile and install

./configure --prefix=/opt/grub-1.96 &&
make &&
make install &&
/opt/grub-1.96/sbin/grub-install /dev/sda

Use

The 915resolution grub patch works exactly like the 915resolution linux utility, so you may view the readme.html for more information. I have provided my example configuration below to show you how I use the utility

insmod 915resolution
915resolution 32 800 480
915resolution 34 800 600
915resolution 38 1024 768
915resolution 3a 1280 1024
915resolution 3c 1600 1200

Now that mode 34 has been set to a resolution that we can use, let's boot the kernel. VGA= modes are mapped as following: 0x200 + MODE (hex). Now mode 34 is the mode we edited, so in hex the mode is 0x234. [Decimal: 564]

linux /vmlinuz root=... vga=564

History

When I first began experimenting with my EeePC 701 4G, I wanted to use the console on the largest resolution setting (800x480). Unfortunately, at that time, the intelfb driver did not allow you to set the mode to anything other then predefined modes in the video bios (640x480 would be the largest choice I could make). Steve Tomljenovic developed 915resolution for a simular problem with the Xorg intel driver (Before they supported modesetting). Unfortunately the intelfb module did not allow me to change video modes after the kernel was booted up. The only possible way for me to use the 800x480 mode, would be to run 915resolution before the kernel booted, and thus the above patch was born.

Credit

915resolution was created by Steve Tomljenovic as a temporary workaround for Xorg Bug#643. I did not drastically modify the code, and either ported C functions to avaliable grub2 functions, or disabled checks when no such function existed.