Exclamation find the right git hash for nexus 5,4 kernel

Hi.
I want to compile a kernel driver (gator) for a nexus 5 and 5 devices.
I want to compile just the kernel, not the whole system, i know how to repack the kernel in the boot.img and upload to the device, that's not an issue.
I checked out the right kernel branch and extra binaries (i have the whole repo really for android platform development).
The insturctions in source.google.com are pretty ****ty and probably not up to date since they do not work.
Also if i try to use
Code:
$ git checkout [commig_hash]
where commit_hash is the hash i take from the kernel version in the "about" screen of my phone (official nexus 4 image) i get a reply that this commit does not exist.
There for it's probably a hash from googles private repo and not the public one.
Anyone knows how i can get the right hash\branch\tag for my image (one for 4.2.2 and one for 4.3).