Intel's Skylake Audio Firmware Lands
Skylake audio having a firmware blob is what the GNU Linux-libre developers were criticizing with one of their changes for Linux 4.3.
The commit mentions, "This adds Skylake audio dsp firmware which will be used in Skylake systems with adsp enabled."
This Skylake audio firmware can be redistributed only in binary form without modification and Intel's binary firmware release license warns against reverse engineering, decompilation, or disassembly. All those firmware license details can be found via the aforementioned commit.
For GNU Linux-libre fans or those wanting to ensure binary firmware blobs are kept to a minimum on their system, Skylake isn't shaping up too well as it also requires binary firmware blobs where it hadn't with previous generations of Iris/HD Graphics.