Reposting from John Stultz’ G+ page:
HDMI audio support has finally been added! Big kudos to Andy Green for the initial driver andfor the Audio HAL.
got abootimg support working in UEFI, so the default build will now just produce a boot.img file which can be flashed to the boot partition (just remember to re-flash the fastboot partition first!). This is more in-line with other Nexus devices and avoids having a fat based boot partition. But don’t fret grub fans, the fat boot partition and grub can still be built/used (just set TARGET_BOOTIMAGE_USE_FAT=true when building). Flash either and it will just work.
The last remaining issue preventing suspend/resume from functioning properly were worked out, so that is now enabled and working!
Dmitry added fiq_debugger* support! So sending brk on the serial port will drop you into an interactive debugger that doesn’t stop the device from running.
* – Well, we’re not doing FIQ bouncing from secure mode yet, so its really just an irq_debugger right now 🙂
The kernel was updated to latest v4.4.12 -stable release!
And of course, a number of smaller features have been added and quite a few bugs solved too.
On the upstream front, a bunch of great work from, , , and landed in 4.7-rc1, so you can now boot HiKey to a shell with the vanilla kernel, and usb and uSD are working too. We’re also pushing to get a number of features merged this cycle, so hopefully things will be shrinking down further.
For more details on how to get started using HiKey with AOSP see: