How to fix ubuntu 12.10 can't start with kernel 3.15?

[lx]

hi all:

I get the kernel in branch:

git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
And I config and make it by:

make localmodconfig
make
make modules_install
make install

when these have done, I reboot the computer. I can see kernel 3.15 in
grub list. When I start with it, the screen is:

Loading Linux 3.15.0-rc5+ ...
Loading initial ramdisk ...

then the screen stopped. So How can fix it?
I can't find any useful error messages because the computer don't get
into the kernel.
Thank you.