normal we use bootloader paramer , but sometimes we may want to use extern
kernel-parameters, or Always use the default kernel command string......
exampel 1:
extern bootargs under kernel
Boot options --->
(quiet) Default kernel commmand string
Kernel command line type (Extend bootloader kernel arguments) --->
example 2:
use kernel command string
Boot options --->
(initrd console=ttymxc0,115200) Defautl kernel command string
Kernel command line type(Always use the default kernel command string) --->