Das U-Boot (subtitled "the Universal Boot Loader" and often shortened to U-Boot; see History for more about the name) is an open-source, primary boot loader used in embedded devices to package the instructions to boot the device's operating system kernel. It is available for a number of computer architectures, including 68k, ARM, Blackfin, MicroBlaze, MIPS, Nios, SuperH, PPC, RISC-V and x86.