如何从源码编译Android Emulator及相关组件？

Prerequisites (Debian) #

Install required dependencies for AOSP and emulator compilation:

sudo apt update && sudo apt install -y openjdk-17-jdk git-core gnupg flex bison build-essential zip curl zlib1g-dev gcc-multilib g++-multilib libc6-dev-i386 libncurses5 lib32ncurses5-dev x11proto-core-dev libx11-dev lib32z1-dev libgl1-mesa-dev libxml2-utils xsltproc unzip fontconfig

Sync Complete AOSP Codebase #

Initialize and sync the main branch, which includes all emulator-related repositories:

repo init -u https://android.googlesource.com/platform/manifest -b main
repo sync -j$(nproc)

Key paths for emulator components:

• Emulator core: external/qemu/
• Device-side client components (OpenGL forwarding, HAL services): frameworks/native/opengl/, hardware/google/emulator/

Component 1: Build Custom Goldfish Kernel #

1. Navigate to the Goldfish kernel directory:

cd kernel/goldfish

2. Configure the kernel for x86_64 emulator:

ARCH=x86_64 make goldfish_x86_64_defconfig

3. Modify kernel code to add custom logs (e.g., add printk statements in driver files), then compile:

ARCH=x86_64 make -j$(nproc)

4. The compiled kernel image is at arch/x86_64/boot/bzImage; specify it with the -kernel flag when launching the emulator.

Component 2 & 3: Build Device-side Images with Custom Logs #

These components are part of the Android system image. Use the following steps:

1. Return to the AOSP root, select the correct build target (replaces the outdated sdk_phone_x86_64-userdebug):

lunch aosp_x86_64-userdebug

For ARM64 emulators, use aosp_arm64-userdebug instead.

2. Add custom logs to device-side code:
   • OpenGL forwarding: Edit files under frameworks/native/opengl/libs/EGL/ or frameworks/native/opengl/libs/GLESv2/, add ALOGD/ALOGV statements
   • Modem HAL services: Edit code in hardware/google/emulator/modem/ to add logs
3. Compile system images:

make -j$(nproc) systemimg vendorimg ramdiskimg

Compiled images are stored in out/target/product/generic_x86_64/.

Component 4: Build Custom Emulator Binary #

Replace the prebuilt emulator binary with your own build:

1. From AOSP root, compile the emulator:

make emulator -j$(nproc)

2. Add custom logs to emulator code: Edit files in external/qemu/ (e.g., client request handling, rendering, input forwarding logic), then re-run make emulator
3. The compiled binary is located at out/host/linux-x86_64/bin/emulator

Launch Custom Emulator #

Combine all components with this example command:

cd out/host/linux-x86_64/bin
./emulator -avd test_avd -kernel ../../../../kernel/goldfish/arch/x86_64/boot/bzImage -system ../../../../out/target/product/generic_x86_64/system.img -vendor ../../../../out/target/product/generic_x86_64/vendor.img -ramdisk ../../../../out/target/product/generic_x86_64/ramdisk.img -verbose

Use -verbose to enable detailed logging for debugging your custom log statements.

Troubleshooting #

• Missing emulator-compatible lunch targets: Ensure you synced the full main branch (partial syncs may omit required configs)
• Emulator build dependency errors: Verify all Debian prerequisites are installed, especially OpenGL-related libraries

内容的提问来源于stack exchange，提问作者Kyoungwon Kim