Modify the linux kernel boot sequence

Modify the linux kernel boot sequence

# Modify the kernel boot sequence 
x86_64 CentOS: 
CAT /boot/grub2/grub.cfg | grep "menuentry"
grub2-set-default 'CentOS Linux (3.10.0-327.el7.x86_64) 7 (Core)' 

arrch64 中标麒麟：
cat /boot/efi/EFI/neokylin/grub.cfg | grep menuentry 
grub2-set-default 'NeoKylin Linux Advanced Server (4.14.0-115.5.1.el7a.06.aarch64) V7.0 (Chromium)'

# View modify the kernel is in effect
Grub2-editenv list