The usb has 2 partitions: VFAT that has the uimage (which comes from the boot folder) and mini1 (ext2) that has the rest of th eimage on it. The raptor original FW will format the usb stick into the two partitons with the plugin TGZ-USB-Installer plug-in.
HDMU_11809_E2_at7500_209_git_5570_nodebug_mix_USB. tar.gz is what i have running on the raptor withbootloader 6.00.
Rhanks for taking the time to look at this.