7 of 17 Reference to Simplest Mac OS X Installation Guide.

10.7.x or 10.8 (Build 12A269) in VirtualBox 4.1.18 or greater

Not mentioned in my earlier answer, an approach to installing and running 10.7 in a VirtualBoxVM. Assume that this approach, originally for 10.7, will be equally good for 10.8.

I'll build this answer over the next few hours, maybe testing as I go. Key points:

  1. some stages of installation make limited (short-term) use of software that is oriented to Osx86
  2. the end result makes minimal use of software that is oriented to Osx86
  3. no patching of Apple files
  4. the end result uses Apple hardware only

– an odour of Hackintosh, which is sometimes contrary to Ask Different FAQ, but points 2, 3 and 4 should keep this answer well within the bounds of what's acceptable. As a courtesy I have flagged a message for moderator attention.


Points below are adapted from a 10.7.3-oriented summary that I offered to Apple in January 2012. No objections were raised.

First draft for public consumption, what's below is a bit of a mash of Lion with Mountain Lion. For the next draft I'll read this alongside the shortlist of seven points at tonymacx86 - Simplest Mac OS X Installation Guide. Someone with recent knowledge of Osx86 might help me to put flesh on the bones; to correct any mistakes; and to simplify.

Key ingredients (not strictly in order)

  • disable EFI
  • -v for verbose boots and shut downs
  • small .iso files, each of which offers a third party boot loader – but beware of the Darwin 11.0.0 effect in Mac OS X 10.7.2 and 10.7.3 machines, where we expect Darwin 11.2.0 and 11.3.0 respectively
  • SATA port 0 present but unused
  • at SATA port 1: a virtual disk image that boots to an installer – hacked from Apple's installer
  • at SATA port 2: a virtual disk image with an installation of Lion or Mountain Lion from that minimalist hack (not ideal)
  • on a USB flash drive, or on anything that can be read within the virtual machine: Apple's true Install Mac OS X Lion.app or Install OS X Mountain Lion.app (either is ideal)
  • at SATA port 0 (zero): a virtual disk image, empty, for the files to be installed by Apple's installer
  • a boot load from an .iso to boot the hacked installer
  • recover installation, use the files that were installed by Apple's installer
  • penultimate boot load with that .iso to boot the clean installation
  • MultiBeast installation of a bare minimum of things that will enable boot without an .iso
  • shut down
  • power off the virtual machine
  • remove the virtual disk images from SATA ports 1 and 2
  • remove the .iso from the virtual CD/DVD drive
  • make the one remaining hard disk the first boot device.

Hints

In the pussycats at SATA ports 0 and 2: to improve performance during stages of installation, you might disable the dynamic_pager daemon —

sudo launchctl unload -w /System/Library/LaunchDaemons/com.apple.dynamic_pager.plist

— but don't forget that you have done so; it may be sane to re-enable that daemon. Meow. Moof.