找不到init进程

小弟用的是ok6410开发板，按照韦老师的 《手把手制作根文件系统的4个视频》先制作了一个最小的文件系统,挂载NFS文件系统，出现
VFS: Mounted root (nfs filesystem) on device 0:14.
devtmpfs: mounted
Freeing init memory: 144K
Failed to execute /linuxrc.  Attempting defaults...
Kernel panic - not syncing: No init found.  Try passing init= option to kernel. See Linux Documentation/init.txt for guidance.
[] (unwind_backtrace+0x0/0xfc) from [] (dump_stack+0x18/0x1c)
[] (dump_stack+0x18/0x1c) from [] (panic+0x60/0x1ac)
[] (panic+0x60/0x1ac) from [] (init_post+0xc8/0x140)
[] (init_post+0xc8/0x140) from [] (kernel_init+0xf4/0x130)
[] (kernel_init+0xf4/0x130) from [] (kernel_thread_exit+0x0/0x8)


找不到init进程，为什么，busybox自带的啊，为什么？求解！