Conti

Replacing graphics subsystems with backports is not trivial in ML as lion simply does not function the same way. I suspect there are other extensions at play here which you have not considered. Yes it is a case of ML not supporting the framebuffer for your graphics device, but there may be a solution... though it may require considerable effort on your part. Easy solutions: Stick with Lion until your next upgrade or swap your graphics device with something known to work. Advanced solutions: Dig into the graphics subsystems further and find a way to get your device to initialize. Sorry I can't help more than that... I have no experience with HD4xxx series graphics.

I am a big fan of Gentoo myself, welcome aboard

As I suspected, based on that installer log your USB was not created correctly and is missing the majority of system files. Either your usb stick is corrupted in general or the mountain lion source you used is, in which case you should attempt a file system repair on the system you got it from and redownload it from the appstore.

ML installation should be a lot more than 500MB... If it is not seeing it even from the USB it isn't an issue with chameleon installation on the drive, it is an issue with OS X installation itself. Could you post a full copy of the installer log output to pastebin.com and link it here?

The default is GraphicsEnabler=Yes PciRoot=0 so really you only need to try PciRoot=1 if the default won't boot - GraphicsEnabler=No will in most cases not function at all with an nvidia graphics card, though it sometimes may if you have installed the nvidia graphics drivers directly from nvidia rather than those from apple. If it still will not load you are having issues with graphics initialization indeed and may need to replace the NV* and GeForce* kexts with more recent versions. Just to confirm - you are attempting to install ML right?

It's actually not stuck at IOBluetoothHCIController - that 'completed' - it is stuck at framebuffer initialization. So like the above poster mentioned it is a graphics related issue. I see that you have integrated graphics only however so you will not find any help from changing the PciRoot flag. You were correct to try the GraphicsEnabler=No flag, which may or may not be required (depends on dsdt, which I do not have time to go through right now, sorry). What you are missing though is probably the correct smbios.plist - you need to emulate a mac model that utilizes the HD3000 for it to be initialized correctly, I had the very same issue on my own i5 2520M notebook not long ago. Once you add the correct smbios.plist to /Extra/ you will either be able to use GraphicsEnabler=Yes or it will require you make a minor modification to the dsdt's GPU0 section to inject the necessary parameters (I had to do this in my case). Good luck to you, I hope this is enough information to help you sort it out, if not let me know and I will post additional information.