Well, this is a list of common boot flags for chameleon based bootloaders, I always forget them, so decided to put it here for “once and for all”… feel free to add more flags in comments if you like 🙂
-x – safe boot
-v – boot in verbose mode, to see actual error or kernel panic error
-f  – reload all kext and dump the boot config cache
-s – single user
-F
If you enter some extra boot flags into org.Chameleon.boot.plist, but they’re messing up your Hackintosh’s bootloader, enter the -F boot flag to ignore them.
-force64
Forces Mac OS X to boot into 64-bit mode.
-legacy
System loads in 32 bit mode while running on 64 bit version of Os X.