Buidling a LXC-ready Android kernel with Gentoo toolchain
To run LXC, we need a kernel that has the options required by LXC on. This article shows how to build an Android kernel that has the required options on, built by Gentoo's latest stable cross-compile toolchain built by
Install Cross-Compile Toolchain
We'll use crossdev, a set of wrapper scripts that provides cross-compilation capability to Portage. The following instructions assume that the workstation is a Gentoo machine.
emerge -av sys-devel/crossdev
Install the latest stable toolchain:
crossdev --stable -t aarch64-unknown-linux-gnu
Clone the kernel sources and compile
The kernel source repository for Nexus 6P with my patches for compiling with GCC 6 as well as LXC-enabled config is at
KireinaHoro/android_kernel_huawei_angler. Clone this repository and compile the kernel:
git clone https://github.com/KireinaHoro/android_kernel_huawei_angler cd android_kernel_huawei_angler make sharkbait_angler_defconfig make -j8
The target kernel image will be available at
arch/arm64/Image.gz-dtb. Copy this to the
preinit repository to continue following Starting Android in LXC to build the
make savedefconfig doesn't really save a working
defconfig, at least it's not the case for Android kernels. When changes are made to
make menuconfig or so), copy
.config back to
arch/arm64/configs instead of relying on the
savedefconfig target, otherwise you may encounter problems such as missing drivers or things that should be built-in turned out to be built as a module.
GCC 6 support was accomplished by introducing
compiler-gcc6.h from SaberMod/android-kernel-lge-hammerhead on GitLab. A few fixes regarding the
static inline behavior change since GCC 6 has been made to make the source compile without problem. Warning checks in
gcc-wrapper.py was disabled as well.