说明：  原创作品，真正可用的超小型 bootloader。将存于norflash里的elf文件装入ram运行，比xilinx提供的bootloader好用多了，至少可以节省你1周的时间. 嵌入式系统用 edk powerpc 或 microblaze 通用
(Original works, the real availability of ultra-small bootloader. load .elf from Norflash move into the ram to run, more useful than the bootloader provided by xilinx , at least 1 week can save you time .embedded systems or microblaze GM edk powerpc application)