Building Kernels

In this document

This page details how to build only the kernel. The following instructions assume you have not downloaded all of AOSP; if you have already done so, you can skip the git clone steps except the step that downloads the kernel sources.

All examples in this section use the panda kernel.

Figuring out which kernel to build

This table lists the name and locations of the kernel sources and binaries:

Device Binary location Source location Build configuration
shamu device/moto/shamu-kernel kernel/msm shamu_defconfig
fugu device/asus/fugu-kernel kernel/x86_64 fugu_defconfig
volantis device/htc/flounder-kernel kernel/tegra flounder_defconfig
hammerhead device/lge/hammerhead-kernel kernel/msm hammerhead_defconfig
flo device/asus/flo-kernel/kernel kernel/msm flo_defconfig
deb device/asus/flo-kernel/kernel kernel/msm flo_defconfig
manta device/samsung/manta/kernel kernel/exynos manta_defconfig
mako device/lge/mako-kernel/kernel kernel/msm mako_defconfig
grouper device/asus/grouper/kernel kernel/tegra tegra3_android_defconfig
tilapia device/asus/grouper/kernel kernel/tegra tegra3_android_defconfig
maguro device/samsung/tuna/kernel kernel/omap tuna_defconfig
toro device/samsung/tuna/kernel kernel/omap tuna_defconfig
panda device/ti/panda/kernel kernel/omap panda_defconfig
stingray device/moto/wingray/kernel kernel/tegra stingray_defconfig
wingray device/moto/wingray/kernel kernel/tegra stingray_defconfig
crespo device/samsung/crespo/kernel kernel/samsung herring_defconfig
crespo4g device/samsung/crespo/kernel kernel/samsung herring_defconfig

After determining the device project you want to work with, view the git log for the kernel binary. Device projects use the form device/<vendor>/<name>.

$ git clone
$ cd panda
$ git log --max-count=1 kernel

The commit message for the kernel binary contains a partial git log of the kernel sources used to build the binary. The first entry in the log is the most recent (the one used to build the kernel). Make a note of the commit message as you will need it in a later step.

Identifying kernel version

To determine the kernel version used in a system image, run the following command against the kernel file:

$ dd if=kernel bs=1 skip=$(LC_ALL=C grep -a -b -o $'\x1f\x8b\x08\x00\x00\x00\x00\x00' kernel | cut -d ':' -f 1) | zgrep -a 'Linux version'

For Nexus 5 (hammerhead), the command is:

$ dd if=zImage-dtb bs=1 skip=$(LC_ALL=C od -Ad -x -w2 zImage-dtb | grep 8b1f | cut -d ' ' -f1 | head -1) | zgrep -a 'Linux version'

Downloading sources

Download the source for the kernel you want to build using the appropriate git clone command:

$ git clone
$ git clone
$ git clone
$ git clone
$ git clone
$ git clone
$ git clone
$ git clone
  • The goldfish project contains the kernel sources for the emulated platforms.
  • The msm project has the sources for ADP1, ADP2, Nexus One, Nexus 4, Nexus 5, Nexus 6, and can be used as a starting point for work on Qualcomm MSM chipsets.
  • The omap project is used for PandaBoard and Galaxy Nexus, and can be used as a starting point for work on TI OMAP chipsets.
  • The samsung project is used for Nexus S, and can be used as a starting point for work on Samsung Hummingbird chipsets.
  • The tegra project is for Xoom, Nexus 7, Nexus 9, and can be used as a starting point for work on NVIDIA Tegra chipsets.
  • The exynos project has the kernel sources for Nexus 10, and can be used as a starting point for work on Samsung Exynos chipsets.
  • The x86_64 project has the kernel sources for Nexus Player, and can be used as a starting point for work on Intel x86_64 chipsets.

Downloading a prebuilt gcc

Ensure the prebuilt toolchain is in your path:

$ export PATH=$(pwd)/prebuilts/gcc/linux-x86/arm/arm-eabi-4.6/bin:$PATH


$ export PATH=$(pwd)/prebuilts/gcc/darwin-x86/arm/arm-eabi-4.6/bin:$PATH

On a Linux host, if you don't have an Android source tree, you can download the prebuilt toolchain from:

$ git clone

Building the kernel

When you know the last commit message for a kernel and have successfully downloaded the kernel source and prebuilt gcc, you are ready to build the kernel. The following build commands use the panda kernel:

$ export ARCH=arm
$ export SUBARCH=arm
$ export CROSS_COMPILE=arm-eabi-
$ cd omap
$ git checkout <commit_from_first_step>
$ make panda_defconfig
$ make

To build a different kernel, simply replace panda with the name of the kernel you want to build.

The kernel binary is output as arch/arm/boot/<kernel_name> and can be copied into the Android source tree to build the matching boot image. Alternatively, you can include the TARGET_PREBUILT_KERNEL variable while using make bootimage (or any other make command line that builds a boot image). This variable is supported by all devices as it is set up via device/common/ For example:

$ export TARGET_PREBUILT_KERNEL=$your_kernel_path/arch/arm/boot/zImage-dtb

Note: Kernel names differ by device. To locate the correct filename for your kernel, refer to device/<vendor>/<name> in the kernel source.