u-boot文档

知呼：

https://zhuanlan.zhihu.com/p/460751954

官网：

https://u-boot.readthedocs.io/en/latest/develop/bloblist.html

51：

https://blog.51cto.com/quantfabric/category5.html

CSDN:

https://blog.csdn.net/ooonebook/category_6484145.html