HTC is making its way through the various flavors of its flagship One M9 and updating them to Android 5.1. You know what comes next: open-source kernel files. The company posted 5.0 kernels for all the variants back in April, but now the first 5.1 kernel is available for the generic international unlocked versions of the One M9. You can download it at the HTC developer center.
At the moment the international model is the first and only M9 to get a Lollipop 5.1 kernel so far - only the One M7 and M8 Google Play Editions (farewell, GPE) have been given the same treatment. They should get around to the various regional and carrier versions at some point - HTC isn't exactly speedy with this stuff, but they are pretty complete. The kernel source code will be a boon to ROM makers and developers who want to modify the original software.
- HTC Developer Center