Develop Android kernels

This page describes how to develop Android kernels on Cuttlefish devices.

Supported kernel manifests

Cuttlefish supports the following kernel manifests on the Android latest release branch and AOSP GSI releases.

• On android-latest-release
  • common-android-mainline
• On android-15.0.0_r36
  • common-android16-6.12
  • common-android15-6.6
  • common-android14-6.1
  • common-android14-5.15
• On aosp-android13-gsi
  • common-android13-5.15
  • common-android13-5.10
• On aosp-android12-gsi
  • common-android12-5.10
  • common-android12-5.4
  • common-android-4.19-stable
• On aosp-android11-gsi
  • common-android11-5.4
  • common-android-4.19-stable
  • common-android-4.14-stable

The following are kernel sources for kernel development on Cuttlefish devices.

• kernel/common-android-mainline
• kernel/common-android16-6.12
• kernel/common-android15-6.6
• kernel/common-android14-6.1
• kernel/common-android14-5.15
• kernel/common-android13-5.15
• kernel/common-android13-5.10

Develop Android kernels

To develop kernels on Cuttlefish devices, follow these steps:

1. Clone the appropriate kernel repo manifest for your Cuttlefish device and make any changes.

   mkdir common-android-mainline
   cd common-android-mainline
   repo init -u https://android.googlesource.com/kernel/manifest -b common-android-mainline
   repo sync -c -j$(nproc) -q

2. Build the kernel and ramdisk. For more information, see Building the Vendor Modules for the Virtual Device.

   tools/bazel run //common-modules/virtual-device:virtual_device_x86_64_dist

   If using common-android-4.19-stable, common-android-4.14-stable, or common-android11-5.4 kernel manifests, run:

   BUILD_CONFIG=common/build.config.gki.x86_64 build/build.sh && BUILD_CONFIG=common-modules/virtual-device/build.config.cuttlefish.x86_64 build/build.sh

   Instead of building locally (to avoid downloading the kernel source, setting up a kernel development environment), you can download the relevant artifacts at ci.android.com.

   • android-mainline
   • android16-6.12
   • android15-6.6
   • android14-6.1
   • android14-5.15
   • android13-5.15
   • android13-5.10
   • android12-5.10
   • android12-5.4
   • android11-5.4

3. Launch the kernel and ramdisk with Cuttlefish.

   cvd create \
       -kernel_path=./out/virtual_device_x86_64/dist/bzImage \
       -initramfs_path=./out/virtual_device_x86_64/dist/initramfs.img

   If launching a non-GKI kernel (anything at or under 4.19), omit the -initramfs_path argument.

   If you're launching the kernel on an aarch64 version of Cuttlefish, use the aarch64 build configuration and use the Image artifact instead of bzImage.

   cvd create \
       -kernel_path=./out/virtual_device_aarch64/dist/Image \
       -initramfs_path=./out/virtual_device_aarch64/dist/initramfs.img