I'm trying to use GRUB2 in graphical mode with 1440x900 resolution, but the result is always garbled nonsense: the highest resolution I can get is 1280x800.

Word is from googling that long as vbeinfo lists a resolution, GRUB2 can use it. This doesn't seem to be true: vbeinfo says that 1440x900 is available but it doesn't work.

Testing it from the GRUB2 command line:

set gxfmode=1440x900
terminal_output gfxterm
# -> garbled nonsense

# back to trusty 640x480
terminal_output console

The graphics card is an Intel GM965.

Once linux boots the framebuffer switches to 1440x900.

Added after epheminent's reply and various experiments

vbeinfo lists two sets of modes.

The first set runs from 0x160 to 0x16b, with resolutions 768x480, 960x600, 1280x800 and 1440x900

Then - after a bunch of text-only modes - the second set, containing resolutions 1024x768, 800x600, and 640x480

The first set of modes aren't altered by 915resolution. They all work except 1440x900.

The resolution of modes in the second set can be altered using the 915resolution module / command available in GRUB2 >= 1.99.

# in /boot/grub/grub.cfg

insmod 915resolution

# 30, 32, 34 all work for me: all that varies is which modes are altered
915resolution 30 1440 900

# setting an impossible resolution changes the mode to "text-only"
# in my case 1280x1024 is not supported
915resolution 30 1280 1024

Clearly, 1440x900 should just work: adding it with 915resolution is just a workaround.