BootDisk Utility is intended to make a external bootable USB Flash Disk by installing to it special Data set (MBR, PBR sectors and Data files) of EFI-based Clover bootloader & Chameleon bootloaders.
In the root directory of the boot disk are numbered boot files. At boot time, for 3 seconds when the flashing line at the top left of the screen, press the corresponding key:
boot (Clover 64bit-default) - no key
boot2 (Chameleon) - 2
boot3 (Clover 32bit - in the last Clover revisions - not included) - 3
boot6 (Clover 64bit - the same default) - 6
boot7 (that includes BiosBlockIO driver for RAID controllers, JMicron, NForce and other non-Intel SATA/ATA/SCSI etc.) - 7