说明：  uboot-ppc源代码： 将uboot 移植到ppc处理器mpc8247/mpc8260/mpc8270上，命令丰富、设备驱动详尽（包括SDRAM、NOR Flash, NAND flash, serial, timer, watchdog等等),对学习理解ppc处理器和板卡很有帮助。
(uboot-ppc src: implemente uboot in ppc processor mpc8247/mpc8270/mpc8260。It has a lot of commands, and many device drivers(sdram, nor flash, nand flash, serial, timer, watchdog and so on). I think it is helpful for your ppc processor and board understanding.)