Both my Fedora 19 & 20 remixes have 'static' kernels. What I mean by that, is when I do a yum update, I have to --exclude=kern* or I have an ubootable system. And that is not enough as you really have to work at it with some packages referencing the newer kernel rpms.

In Fedora 21 they have a current kernel that works on a lot of boards. So the question for you people that understand kernels (which I do not):

Is it possible to take the Fedora 19 kernel and get it working for all boards?

or

Is it better to take the Fedora 21 kernel and backport it to F19/Centos7?

or

A kernel is really a kernel and the Fedora 21 kernel will work just fine with Centos7-arm.

After uboot and kernel, it is 'just' a matter of recompiling stuff for arm. Noarch rpms can just be moved over; or else they are really not noarch...

Note that for my epel6 needs for RSEL6, I took a number of noarch rpms from the epel6-i386 repo and locally installed them to meet some messed up versioning challenges I had for my mailserver.