ucos-ppc，将ucos 2.52移植到ppc处理器mpc8247/8270/8260上。这里ucos运行时已经用uboot加载，所以省略了一些系统初始化的过程，但任务切换、中断响应、bsp还是有一定参考价值，且附带了bsp的应用编程接口。-ucos-ppc, implement ucos 2.52 in ppc processer mpc8247/mpc8270/mpc8260。Here ucos is bootloaded by uboot, so it omits several in