android-build

# Android Build Systems This skill covers building Android apps via Gradle CLI and building custom ROMs via AOSP/LineageOS. --- ## App Building (Gradle CLI) ### Essential Commands ```bash ./gradlew tasks # List available tasks ./gradlew assembleDebug # Build debug APK ./gradlew assembleRelease # Build release APK ./gradlew installDebug # Build + install to device ./gradlew bundleRelease # Build AAB (App Bundle) # APK output location # app/build/outputs/apk/debug/app-debug.apk # app/build/outputs/apk/release/app-release.apk ``` ### Build Variants ```bash ./gradlew assembleFreeDebug # Flavor + build type ./gradlew assemblePaidRelease ./gradlew assembleDebug --info # Verbose output ./gradlew assembleRelease -x test # Skip tests ``` ### Testing ```bash ./gradlew test # Unit tests ./gradlew testDebugUnitTest # Debug unit tests only ./gradlew connectedAndroidTest # Instrumented tests ./gradlew connectedCheck # All connected tests # Run specific test ./gradlew test --tests "*.MyTestClass" ``` ### Linting & Analysis ```bash ./gradlew lint # Run lint ./gradlew lintDebug # Debug only (faster) ./gradlew ktlintCheck # Kotlin style (if configured) ./gradlew detekt # Detekt analysis (if configured) ``` ### Clean & Refresh ```bash ./gradlew clean # Clean build ./gradlew clean assembleDebug # Clean + build ./gradlew --refresh-dependencies # Force dependency refresh ./gradlew --stop # Stop Gradle daemon ``` ### Dependencies ```bash ./gradlew dependencies # All dependencies ./gradlew app:dependencies # Module dependencies ./gradlew dependencyInsight --dependency <name> ``` ### Signing Debug keystore location: - Linux: `~/.android/debug.keystore` - macOS: `~/.android/debug.keystore` - Windows: `C:\Users\<user>\.android\debug.keystore` Password: `android`, Alias: `androiddebugkey` ```bash # Create release keystore keytool -genkey -v -keystore release.keystore \ -alias my-key-alias -keyalg RSA -keysize 2048 -validity 10000 ``` ### Performance ```bash ./gradlew assembleDebug --parallel # Parallel builds ./gradlew assembleDebug --build-cache # Use cache ./gradlew assembleDebug --offline # Offline mode ./gradlew --scan # Build scan (uploads data) ./gradlew --profile # Local profile report ``` ### gradle.properties Optimization ```properties org.gradle.jvmargs=-Xmx4g -XX:+HeapDumpOnOutOfMemoryError org.gradle.parallel=true org.gradle.caching=true org.gradle.configuration-cache=true android.useAndroidX=true ``` --- ## SDK Management ### sdkmanager ```bash sdkmanager --list # List available packages sdkmanager --list | grep system # Filter system images sdkmanager "platform-tools" # Install package sdkmanager "platforms;android-34" # Install platform sdkmanager "system-images;android-34;google_apis;x86_64" sdkmanager --update # Update all sdkmanager --licenses # Accept licenses ``` ### avdmanager ```bash avdmanager list device # List device profiles avdmanager list avd # List created AVDs # Create AVD avdmanager create avd -n my_avd \ -k "system-images;android-34;google_apis;x86_64" \ -d pixel_6 avdmanager delete avd -n my_avd ``` ### Emulator CLI ```bash emulator -list-avds # List AVDs emulator @my_avd # Start AVD emulator @my_avd -no-snapshot # Fresh boot emulator @my_avd -no-window # Headless emulator @my_avd -wipe-data # Factory reset ``` --- ## ROM Building (AOSP/LineageOS) ### Environment Setup ```bash # Install repo tool mkdir -p ~/.bin curl https://storage.googleapis.com/git-repo-downloads/repo > ~/.bin/repo chmod a+x ~/.bin/repo export PATH="$HOME/.bin:$PATH" # Initialize repo mkdir android && cd android repo init -u https://github.com/LineageOS/android.git -b lineage-21.0 # Or AOSP: repo init -u https://android.googlesource.com/platform/manifest # Sync source repo sync -c -j$(nproc) --force-sync --no-tags --no-clone-bundle ``` ### Build Commands ```bash # Setup environment source build/envsetup.sh # Select device lunch <device>-userdebug # AOSP breakfast <device> # LineageOS # Build m # Full build mka bacon # LineageOS (with flashable zip) mka bootimage # Just boot.img mka systemimage # Just system # Parallel build m -j$(nproc) ``` ### Build Variants | Variant | Purpose | | ----------- | -------------------------------------- | | `user` | Production, no root, limited debugging | | `userdebug` | Like user + root + debugging | | `eng` | Development, all debug tools | ### Common Targets ```bash m bootimage # Kernel + ramdisk m systemimage # System partition m vendorimage # Vendor partition m otapackage # OTA zip mka bacon # LineageOS flashable zip # Module-specific m Settings # Just Settings app mm # Build current directory mmm packages/apps/Settings # Build specific path ``` ### LineageOS Specifics ```bash breakfast <device> # Setup + sync device deps brunch <device> # breakfast + mka bacon # Cherry-pick from Gerrit repopick <change_number> repopick -t <topic> # Sync specific project repo sync packages/apps/Settings ``` ### Build Output ``` out/target/product/<device>/ ├── boot.img # Kernel + ramdisk ├── system.img # System partition ├── vendor.img # Vendor partition ├── lineage-*.zip # Flashable zip (LineageOS) └── recovery.img # Recovery (non-A/B) ``` --- ## Device Trees ### Structure ``` device/<vendor>/<device>/ ├── AndroidProducts.mk # Product makefiles list ├── BoardConfig.mk # Board configuration ├── device.mk # Device makefile ├── lineage_<device>.mk # LineageOS product ├── extract-files.sh # Vendor blob extraction ├── proprietary-files.txt # Blob list ├── sepolicy/ # SELinux policies └── overlay/ # Resource overlays ``` ### Key Files **BoardConfig.mk** - Hardware configuration: ```makefile TARGET_ARCH := arm64 TARGET_BOARD_PLATFORM := <platform> TARGET_BOOTLOADER_BOARD_NAME := <device> BOARD_KERNEL_CMDLINE := ... BOARD_BOOT_HEADER_VERSION := 4 ``` **device.mk** - Device packages: ```makefile PRODUCT_PACKAGES += \ android.hardware.audio@7.0-impl \ audio.primary.$(TARGET_BOARD_PLATFORM) PRODUCT_COPY_FILES += \ $(LOCAL_PATH)/configs/audio_policy.conf:... ``` --- ## Kernel Building ### Standalone ```bash # Setup export ARCH=arm64 export CROSS_COMPILE=aarch64-linux-gnu- # Or for Clang: export CC=clang export CLANG_TRIPLE=aarch64-linux-gnu- # Configure make <device>_defconfig # Build make -j$(nproc) # Output arch/arm64/boot/Image.gz ``` ### In AOSP Tree ```makefile # In BoardConfig.mk TARGET_KERNEL_SOURCE := kernel/<vendor>/<device> TARGET_KERNEL_CONFIG := <device>_defconfig TARGET_KERNEL_CLANG_COMPILE := true ``` --- ## Troubleshooting ### Common Gradle Issues ```bash # OOM export GRADLE_OPTS="-Xmx4g" # Daemon issues ./gradlew --stop rm -rf ~/.gradle/daemon # Cache issues ./gradlew clean --refresh-dependencies ``` ### Common AOSP Issues ```bash # Ninja error - usually dependency issue m clean && m # Jack server (old builds) ./prebuilts/sdk/tools/jack-admin kill-server ./prebuilts/sdk/tools/jack-admin start-server # SELinux issues audit2allow -i audit.log ``` ### Build Logs ```bash # Gradle ./gradlew assembleDebug --stacktrace ./gradlew assembleDebug --info # AOSP m 2>&1 | tee build.log ``` --- ## Quick Reference ### Gradle | Task | Command | | ------------- | --------------------------- | | Build debug | `./gradlew assembleDebug` | | Build release | `./gradlew assembleRelease` | | Install | `./gradlew installDebug` | | Test | `./gradlew test` | | Lint | `./gradlew lint` | | Clean | `./gradlew clean` | | Dependencies | `./gradlew dependencies` | ### AOSP/LineageOS | Task | Command | | ------------- | -------------------------- | | Setup env | `source build/envsetup.sh` | | Select device | `lunch <device>-userdebug` | | Full build | `m` | | LineageOS zip | `mka bacon` | | Just boot | `mka bootimage` | | Sync | `repo sync -c -j$(nproc)` |