android11 开搞
朋友们，最近拿到 androidR 的代码了，让我们来康康有哪些变动，一上来就给我整懵了，编译了 SystemUI 后发现
居然跑到 system\system_ext\priv-app 文件下了，这是什么鬼，又新加分区？之前 Q 版本已经新增了 product 分区，
并且 SystemUI、Launcher3、Settings这些核心应用都存放在此处，现在 R 版本又跑到这个 system_ext 分区下了
关于动态分区之前介绍过 Android10 动态分区介绍
一探究竟
决定编译后 apk 的位置当然是在 Android.mk 或者 Android.bp 中啦，那我们去康康到底配置了啥子属性？
vendor\mediatek\proprietary\packages\apps\SystemUI\Android.bp
system_ext_specific: true,
privileged: true,
vendor\mediatek\proprietary\packages\apps\MtkSettings\Android.bp
system_ext_specific: true,
privileged: true,
packages\apps\Launcher3\Android.mk
LOCAL_PRIVILEGED_MODULE := true
LOCAL_SYSTEM_EXT_MODULE := true
vendor\mediatek\proprietary\packages\apps\Browser\Android.mk
LOCAL_SYSTEM_EXT_MODULE := true
看完上面这些配置可以知道了，
bp 中配置 system_ext_specific: true，就将编译到 system\system_ext\ 中，
privileged: true 决定在 priv-app 文件中，不加 privileged 则编译到 system\system_ext\app\
mk 中配置 LOCAL_SYSTEM_EXT_MODULE := true，就将编译到 system\system_ext\ 中，
LOCAL_PRIVILEGED_MODULE := true 决定在 priv-app 文件中，不加 LOCAL_PRIVILEGED_MODULE 则编译到 system\system_ext\app\
system_ext_specific 和 LOCAL_SYSTEM_EXT_MODULE 的对照关系经过搜索位于
build\soong\androidmk\androidmk\android.go
addStandardProperties(bpparser.BoolType, map[string]string{ // Bool properties "LOCAL_IS_HOST_MODULE": "host", "LOCAL_CLANG": "clang", "LOCAL_FORCE_STATIC_EXECUTABLE": "static_executable", "LOCAL_NATIVE_COVERAGE": "native_coverage", "LOCAL_NO_CRT": "nocrt", "LOCAL_ALLOW_UNDEFINED_SYMBOLS": "allow_undefined_symbols", "LOCAL_RTTI_FLAG": "rtti", "LOCAL_PACK_MODULE_RELOCATIONS": "pack_relocations", "LOCAL_TIDY": "tidy", "LOCAL_USE_CLANG_LLD": "use_clang_lld", "LOCAL_PROPRIETARY_MODULE": "proprietary", "LOCAL_VENDOR_MODULE": "vendor", "LOCAL_ODM_MODULE": "device_specific", "LOCAL_PRODUCT_MODULE": "product_specific", "LOCAL_SYSTEM_EXT_MODULE": "system_ext_specific", "LOCAL_EXPORT_PACKAGE_RESOURCES": "export_package_resources", "LOCAL_PRIVILEGED_MODULE": "privileged", "LOCAL_AAPT_INCLUDE_ALL_RESOURCES": "aapt_include_all_resources", "LOCAL_DONT_MERGE_MANIFESTS": "dont_merge_manifests", "LOCAL_USE_EMBEDDED_NATIVE_LIBS": "use_embedded_native_libs", "LOCAL_USE_EMBEDDED_DEX": "use_embedded_dex", "LOCAL_DEX_PREOPT": "dex_preopt.enabled", "LOCAL_DEX_PREOPT_APP_IMAGE": "dex_preopt.app_image", "LOCAL_DEX_PREOPT_GENERATE_PROFILE": "dex_preopt.profile_guided", "LOCAL_PRIVATE_PLATFORM_APIS": "platform_apis", "LOCAL_JETIFIER_ENABLED": "jetifier", }) }
那么 LOCAL_SYSTEM_EXT_MODULE 这个又是在那里使用的呢？继续在 build 中查找
build\make\core\base_rules.mk
else ifneq ($(filter $(TARGET_OUT_SYSTEM_EXT)/%,$(_path)),) LOCAL_SYSTEM_EXT_MODULE := true endif _path := else ifeq (true,$(strip $(LOCAL_SYSTEM_EXT_MODULE))) partition_tag := _SYSTEM_EXT # A system_ext-specific module could be on the system_ext partition at # "system_ext" or the system partition at "system/system_ext". actual_partition_tag := $(if $(filter true,$(BOARD_USES_SYSTEM_EXTIMAGE)),system_ext,system)
紧接着查找 TARGET_OUT_SYSTEM_EXT 到
build\make\core\envsetup.mk
TARGET_OUT_SYSTEM_EXT := ( P R O D U C T O U T ) / (PRODUCT_OUT)/(PRODUCT
O
UT)/(TARGET_COPY_OUT_SYSTEM_EXT)
TARGET_COPY_OUT_SYSTEM_EXT := $(_system_ext_path_placeholder)
_system_ext_path_placeholder := ||SYSTEM_EXT-PATH-PH||
再接着找 SYSTEM_EXT
build\make\tools\releasetools\check_target_files_vintf.py
# each partition. DIR_SEARCH_PATHS = { '/system': ('SYSTEM',), '/vendor': ('VENDOR', 'SYSTEM/vendor'), '/product': ('PRODUCT', 'SYSTEM/product'), '/odm': ('ODM', 'VENDOR/odm', 'SYSTEM/vendor/odm'), '/system_ext': ('SYSTEM_EXT', 'SYSTEM/system_ext'), }
build\make\target\board\BoardConfigEmuCommon.mk
ifeq ($(QEMU_USE_SYSTEM_EXT_PARTITIONS),true) BOARD_EMULATOR_DYNAMIC_PARTITIONS_PARTITION_LIST := \ system \ system_ext \ product \ vendor TARGET_COPY_OUT_PRODUCT := product BOARD_PRODUCTIMAGE_FILE_SYSTEM_TYPE := ext4 TARGET_COPY_OUT_SYSTEM_EXT := system_ext BOARD_SYSTEM_EXTIMAGE_FILE_SYSTEM_TYPE := ext4 else TARGET_COPY_OUT_PRODUCT := system/product TARGET_COPY_OUT_SYSTEM_EXT := system/system_ext BOARD_EMULATOR_DYNAMIC_PARTITIONS_PARTITION_LIST := \ system \ vendor endif
build\make\core\board_config.mk
# Now we can substitute with the real value of TARGET_COPY_OUT_SYSTEM_EXT ifeq ($(TARGET_COPY_OUT_SYSTEM_EXT),$(_system_ext_path_placeholder)) TARGET_COPY_OUT_SYSTEM_EXT := system/system_ext else ifeq ($(filter system_ext system/system_ext,$(TARGET_COPY_OUT_SYSTEM_EXT)),) $(error TARGET_COPY_OUT_SYSTEM_EXT must be either 'system_ext' or 'system/system_ext', seeing '$(TARGET_COPY_OUT_SYSTEM_EXT)'.) endif PRODUCT_COPY_FILES := $(subst $(_system_ext_path_placeholder),$(TARGET_COPY_OUT_SYSTEM_EXT),$(PRODUCT_COPY_FILES))
行了，就先整这么多吧，到这里已经很清楚了。
