Is rescueOS bootable from an SD card, though?
~ $ cat /etc/bootmenu.d/73-RescueOS-2.6.37-direct_SD.item ITEM_NAME="RescueOS direct boot from SD" ITEM_KERNEL="2.6.37" #ITEM_INITRD="rescueOS-1.0.img" #now symlinked to latest img ITEM_INITRD="rescueOS.img" ITEM_CMDLINE="rootdelay root=/dev/ram0" ITEM_OMAPATAG="1" ITEM_DEVICE="${EXT_CARD}p1" ITEM_FSTYPE="fat"