1.boot partition contents are emptied, the system can not start normally.
2.how to re-install the kernel it? You can not use the system first disc, install the kernel, there are too many dependent packages need to be installed. Use the second disc do the kernel source installed, I don’t know how to operate it.
Care to share how it became completely empty? That seems a little odd,
and so I wonder if perhaps it is just not mounted into the root filesystem
when you are looking at /boot which would mean you just need to make sure
that it (the /boot filesystem) is found by Grub.
If it really has been wiped out then you should use DVD 1 to recover by
booting into recovery mode. It’s made to do this kind of things. DVD 2 is
basically never used unless you really need source, so don’t bother.
Good luck.