Kernel 2.6.29 introduced the Kernel Mode Setting feature, meaning the kernel to be able to change resolution and adresse other outputs. For example kernels pre 2.6.29 always actived the external DVI device (if connected) on my macbook and showed boot screens there. This is now configurable. Also switching between X11 and console is much faster.
To get KMS running on my macbook, I installed the 2.6.29 with the following settings
Device Drivers ---> Graphics support ---> <*> Direct Rendering Manager (XFree86 4.1.0 and higher DRI support) ---> <*> Intel 830M, 845G, 852GM, 855GM, 865G (i915 driver) ---> i915 driver [ ] Enable modesetting on intel by default
You don't have to enable KMS by default. It's possible to do this via i915.modeset=1 as a boot option.
After booting the kernel, drm should have detected your outputs and load inteldrmfb
[ 1.905481] [drm] TV-15: set mode NTSC 480i 0 [ 2.021462] allocated 1280x800 fb: 0x00fdf000, bo ffff88013eaf2900 [ 2.094941] [drm] LVDS-8: set mode 1280x800 17 [ 2.191879] Console: switching to colour frame buffer device 160x50 [ 2.195013] fb0: inteldrmfb frame buffer device [ 2.195038] registered panic notifier [ 2.195059] [drm] Initialized i915 1.6.0 20080730 on minor 0
To use KMS within X11, I had to update the latest xorg-server, x11-libs and xf86-video-intel from the x11-overlay. In /etc/X11/xorgs.conf must
Option "AccelMethod" "UXA"
set in the intel driver section.
Notice that output names may have changed, if you use a multimonitor setup oder xrandr. I had VGA,TV,LVDS,TMDS-1 prior to 2.6.29 and now it's VGA1,TV1,LVDS1,DVI1.