What are the correct append parameters to make bt4-final boot via a pxe server? All I can find on the internet is the following:

LABEL backtrack
KERNEL /backtrack/vmlinuz-
APPEND netboot=http httproot=http://10.x.x.x/backtrack initrd=/backtrack/initrd.img- vga=791 ramdisk_size=10000 root=/dev/ram0 rw

Unfortunately i am doing something wrong because after vmlinuz and initrd are loaded (and executed) I get a busybox shell...I can provide both nfs and http(s) exports for mountpoints. It seems af if the final bt4 dvd doesn't contain the pxe script anymore..