Sources required to be on hand beneath the GPL are actually prepared for devs to check out
Proper on time, the entire kernel sources for each the HTC One and Galaxy S4 Google Play edition devices are ready for download courtesy of links from JBQ on the Android Building Group. For the enterprising developers that want (or need) it to work with for a deeper understanding of these two devices, the kernel source is a big resource to have available. This isn’t at all unexpected, however, as the terms of the GPL require that it be made freely available.
It should also be noted that the availability of the kernel source for these devices doesn’t mean that we have a full ROM or any proprietary binaries available. Things in this area are understandably still a little murky, and while we surely hope that those additional files that would give users a complete working ROM will be offered, nothing is guaranteed.
If you are someone who has a need for the kernel source and want to get right into it, you can grab a direct download for both devices from the “download” links below. HTCdev is also hosting an independent download from its own site for the HTC One.
Source: Android Building Group