I tried that,but the image with 4.x kernel and desktop have something wrong with its boot script(a wrongly filesystem fix),which destroy its filesystem everytime when it's booting and I don't know how to edit it.And the other one with 5.x kernel but no desktop,after I installed xserver-xorg-core or xserver-xorg-core-rockchip and rebooted,it stoped display through HDMI (keyboard seemed work because it reacted after I pressed NumLock)(I had installed xfce4 before I install those packages),but when I checked /var/log/message, I found no error.I also tried to copy /boot from the image with 5.x kernel to the other one, still didn't work.