boot flags are placed at the boot prompt before executing the com.apple.boot.plist file to start OS X and give the system a "heads-up" to know how you want to start up... when your computer is showing a countdown (right after your BIOS logo screen) press any key (or f8 or whatever it says when booting up a DVD/CD) and then simply input that string of "-f -x -v"

By messing with the BIOS, you aren't looking to make the system think a SATA connection is an IDE connection... we are trying to look into AHCI issues. also, by making your system boot in any legacy mode (at least for starters until we get things installed).

Best of luck

---