@WaseemAlkurdi: My bad, I was thinking of the PW2, which moved to an i.MX6SL.
The rest still stands though

. The libc might be an issue because it can be compiled to *require* a minimum kernel version.
EDIT: Although, you might be in luck, since FW 5.9.7 was apparently still setup to support Linux 2.6.32, even on PW2+ which moved at least to 3.0.35

.
The K4 was a funny beast in that it was essentially a K5 masquerading as a K3. The hardware is roughly similar to a K5, but it's running on what's essentially the K3 FW. There's even a nifty epdc shim to bridge between the two different epdc APIs.