mmmm, are you sure about that external SD card bootmenu item ? When trying that I'm getting in U-Boot : And I'm being dropped in the U-Boot console. The 3rd partition (the FAT one) on the SD card does not contain a boot.scr file, only a kernel config text file, a kernel memory map text file, the vmlinuz version of the kernel and the uImage version of the kernel. No boot.scr file.