Make a Chameleon-based USB boot thing, presuming you have access to another machine (!).
Then you can/should be able to boot from that (unless theres some BIOS fault), and using Chameleon, provided that the original HD install is still there (disk OK), you ought to be able to select that (original install on HD) and boot that, then go and repair the boot stuff on the HD. (Reinstall Chameleon/re-run net book installer etc).
Or, (again, presuming access to another machine), pull the drive and connect via USB-SATA interface to 2nd Mac, and reinstall Chameleon.
If/when you are able to boot into OSX on the original HD, may be a good idea to first boot into Single User Mode and run /sbin/fsck as prompted. Hopefully the OSX install is not "trashed" beyond repair!