Requested and received. I've merged the Jolla kernel source release (kernel-adaptation-sbj-3.4.0.20131115.2) on top of tagged Qualcomm (Android) kernel release so that it's possible to view all Jolla specific changes. Only really major change I noticed in my first quick glance through it, was that they've backported btrfs (from linux-stable 3.5.7). Other than that, their changes are mostly hardware enablement related (display, touchscreen, camera, sensor, etc drivers). Stuff you'd see in any kernel source for any e.g. Android device. Vast majority of their (or their ODM's) changes are even commented (who, when, what) which is great compared to some other stuff I've seen. In general quite clean, though I (literally :P) see red when I see all those whitespaces.

I've pushed the source to my GitHub. Happy forking.
https://github.com/KonstaT/sailfisho..._jolla_msm8930

I can write some instructions if someone is interested in building/booting custom kernels. It should be pretty basic stuff for anyone familiar with e.g. Android development (and the necessary tools are the same). From a brief chat I had with a Jolla engineer, flashing/booting a custom kernel image will result a permanent unlocked status (in bootloader?) and it will most likely void your warranty!

Edit. Stskeeps has cleared the situation in this post:
http://talk.maemo.org/showpost.php?p...8&postcount=40

Flashing/booting a kernel image using fastboot is not possible without 'fastboot oem unlock', which will most likely void your warranty. Flashing a kernel image using root/developer mode is possible. Flashing kernel images to recovery partition instead should be more suitable for any possible experiments at least for now (until actual Jolla system recovery is added in a future update).