This is my customized linux kernel for the Nexus 9 Android tablet based on ElementalX kernel. This kernel features a battery-friendly CPU frequency governor—Sublime Active—which scales the CPU frequency less aggressively than the default CPU frequency governor (Interactive) for Nexus devices, which results in a 20% reduction in battery usage.

• Sublime Active CPU frequency governor
• Touch CPU quiet governor
• Optimized ZRAM
• 2.0 Amp charging
• IO Schedulers: noop, fiops, sio, bfq
• USB fast-charge
• Double tap to wake
• Sweep to wake
• Sweep to sleep
• CPU overclocking up to 2.5 Mhz
• GPU overclocking up to 984 Mhz
• NTFS and exFAT support

Download the build dependencies:

$ sudo apt-get install build-essential zip 

Create a project directory

$ mkdir sublime && cd sublime

Clone a toolchain for building the kernel

$ git clone https://bitbucket.org/UBERTC/aarch64-linux-android-4.9-kernel.git ubertc-4.9

Clone the source

$ git clone https://github.com/beta1440/linux-flounder.git

Set the cross compiler prefix

$ export CROSS_COMPILE=$(pwd)/ubertc-4.9/bin/aarch64-linux-android-

Additionally, you may want to add the bin folder of the gcc cross compiler to your path. Build the kernel

$ cd linux-flounder
$ make prepare
$ make sublime_defconfig
$ make otapackage -j4

The OTA package should be inside the android directory.

To change the directory of the created OTA package, set the environment variable KBUILD_FLOUNDER_OUTPUT to the absolute path of your preferred output directory.