layout: post title: libbpf-bootstrap-android date: 2023-9-14 16:18 category: Framework author: JiaHuann tags: [Android, ebpf-framework, cross-compile] summary: For amd64 aarch machine to directly using libbpf-bootstrap framwork to write ebpf programs both kernel and user space.And you don't need to have CONFIG_BTF_DEBUG_INFO support by using externel BTF file in BTFhubForAndroid instead.For this goal,I did some changes on libbpf-bootstrap,and have done some embedded features.Wish this can help you sth.Best regards.

Libbpf-bootstrap for android

For amd64 aarch machine to directly using libbpf-bootstrap framwork to write ebpf programs both kernel and user space.And you don't need to have CONFIG_BTF_DEBUG_INFO support by using externel BTF file in BTFhubForAndroid instead.For this goal,I did some changes on libbpf-bootstrap,and have done some embedded features.Wish this can help you sth.Best regards.

upstream:

• https://github.com/libbpf/libbpf-bootstrap
• https://github.com/SeeFlowerX/BTFHubForAndroid

prerare

• Android NDK
• gcc-aarch64-linux-gnu
• Android phone with root and unlock BL

usage

• deps

  https://github.com/JiaHuann/libbpf-bootstrap-android
  cd libbpf-bootstrap-android
  sudo apt install gcc-aarch64-linux-gnu llvm clang 
  wget https://dl.google.com/android/repository/android-ndk-r25c-linux.zip?hl=zh-cn android-ndk-r25c-linux.zip
  unzip android-ndk-r25c-linux

• set NDK env to $PATH

  vim ~/.bashrc
  export your android-ndk-r25c/toolchains/llvm/prebuilt/linux-x86_64/bin to PATH

• compile and push to phone

  
  cd examples/c && make

adb devices adb remount # may fail, you can leave with issure. adb push examples/c/btf_file/* example/c/your_executable_file /data/local/tmp adb shell #into android kernel shell

- in android shell
```shell
cd /data/local/tmp && chmod +x your_excutable_file
./run
Congratulations!

feature

• libelf,libz on aarcj64 embedded.
• x86 -> android13(aarch64) cross-compile you can directly write ebpf both kernel-program and user-program on x86 machine.
• FlameGraph embedded to monitor performance.
• For None BTF/vmlinux android-kernel(CONFIG_DEBUG_INFO_BTF not set) support.
• adb debug (after compiling&linking, directly push into android-phone) embedded.

RoadMap:

• change the static link to ShareLib.
• Measure the eBPF program's overhead by FlameGraph.
• Add more Android features into support.
• Test for lower Android version.