1.Kernel hacking ---> Kernel low-level debugging functions --> Early printk
2.boot option中你需要添加 earlyprintk项。类似于:console=ttySAC0,115200 root=/dev/mtdblock3 rootfstype=jffs2 earlyprintk
如何打开kernel最开始的打印
原文:https://www.cnblogs.com/kent-hu/p/9434161.html