Select the newest branch available. This step is not necessary with Omni because Omni already includes TWRP source by default.
If you are using CM 12.0 then you will probably want to cherry pick this patch into external/sepolicy:http://review.cyanogenmod.org/#/c/89474/
根据 Dees-Troy 的原话。需要修改 external/sepolicy的源代码添加对 twrp的支持。
为了能根据编译不同的Recovery而把sepolicy相关支持添加到源代码了。
我的修改内容如下：
https://github.com/sndnvaps/android_device_lge_hammerheadcaf/commit/7d9aeec2fb74a9c63e35fedfb4b74ff1725063a8