Android 编译如何跳过生成ota package过程？
2020-10-09 本文已影响0人
dexfire
通常来说，OTA是用户比较接受的升级方式，但对于开放性比较高的ROM却不适用，因为OTA从原理上讲，是利用现有文件进行补丁升级，因此需要系统文件严格保持完整性才能正确应用更新。而LineageOS和RROS的编译系统，似乎也不能正确生成OTA更新包，而且同样会占用较长的编译时间（对于我的笔记本来说，10min左右），因此可以选择关闭本功能。
如何禁用OTA更新包生成？
AOSP从Android Oreo版本开始引进ninja编译管理系统，因此对于刚刚入门的编译者可能无从下手，但是实际上这种改变也仅仅是部分的将原有的Makefile（Android.mk）升级为blueprint（Android.bp)格式，此外也依然兼容原有Makefile编译系统（本质上依然使用make命令进行实际编译），而且项目的基本结构是未发生任何变化的，所以其实还是考验编译维护者对系统的熟悉程度。
解决方案
在所选用的device中BoardConfig.mk文件，修改或者增加一行TARGET_SKIP_OTA_PACKAGE := true 即可在构建时不生成ota更新包。
下面是找解决方法中的一些碎碎念，可以选择性忽略...当然看看也是不错哒
解决思路
首先我们知道编译时的生成文件是类似下面这样的：
make ota package
那么我们要做的就是，找到这个编译目标，这可以通过看详细日志来解决，也可以通过搜索文件全文来查找。
通过查找关键字，可以找到：
$ grep -arnw "otapackage" .
./build/make/core/Makefile:4317:.PHONY: otapackage
./build/make/core/Makefile:4318:otapackage: $(INTERNAL_OTA_PACKAGE_TARGET)
./build/make/core/Makefile:4344:otapackage otardppackage: $(INTERNAL_OTA_RETROFIT_DYNAMIC_PARTITIONS_PACKAGE_TARGET)
也就是定义在 ./build/make/core/Makefile： 4317 附近的一个伪目标，进一步打开这个文件，可以看到其中有这样一段代码：
.PHONY: target-files-package
target-files-package: $(BUILT_TARGET_FILES_PACKAGE)
ifneq ($(filter $(MAKECMDGOALS),target-files-package),)
$(call dist-for-goals, target-files-package, $(BUILT_TARGET_FILES_PACKAGE))
endif
# -----------------------------------------------------------------
# NDK Sysroot Package
NDK_SYSROOT_TARGET := $(PRODUCT_OUT)/ndk_sysroot.tar.bz2
$(NDK_SYSROOT_TARGET): $(SOONG_OUT_DIR)/ndk.timestamp
@echo Package NDK sysroot...
$(hide) tar cjf $@ -C $(SOONG_OUT_DIR) ndk
$(call dist-for-goals,sdk,$(NDK_SYSROOT_TARGET))
ifeq ($(build_ota_package),true)
# -----------------------------------------------------------------
# OTA update package
# $(1): output file
# $(2): additional args
define build-ota-package-target
PATH=$(foreach p,$(INTERNAL_USERIMAGES_BINARY_PATHS),$(p):)$$PATH MKBOOTIMG=$(MKBOOTIMG) \
build/make/tools/releasetools/ota_from_target_files -v \
--block \
--extracted_input_target_files $(patsubst %.zip,%,$(BUILT_TARGET_FILES_PACKAGE)) \
-p $(HOST_OUT) \
--backup=$(backuptool) \
$(if $(OEM_OTA_CONFIG), -o $(OEM_OTA_CONFIG)) \
$(2) \
$(BUILT_TARGET_FILES_PACKAGE) $(1)
endef
name := $(TARGET_PRODUCT)
ifeq ($(TARGET_BUILD_TYPE),debug)
name := $(name)_debug
endif
name := $(name)-ota-$(FILE_NAME_TAG)
INTERNAL_OTA_PACKAGE_TARGET := $(PRODUCT_OUT)/$(name).zip
INTERNAL_OTA_METADATA := $(PRODUCT_OUT)/ota_metadata
$(INTERNAL_OTA_PACKAGE_TARGET): KEY_CERT_PAIR := $(DEFAULT_KEY_CERT_PAIR)
ifeq ($(AB_OTA_UPDATER),true)
$(INTERNAL_OTA_PACKAGE_TARGET): $(BRILLO_UPDATE_PAYLOAD)
else
$(INTERNAL_OTA_PACKAGE_TARGET): $(BROTLI)
endif
ifeq ($(TARGET_OTA_ASSERT_DEVICE),)
OTA_SCRIPT_OVERRIDE_DEVICE := auto
else
OTA_SCRIPT_OVERRIDE_DEVICE := $(TARGET_OTA_ASSERT_DEVICE)
endif
ifneq ($(RR_BUILD),)
$(INTERNAL_OTA_PACKAGE_TARGET): backuptool := true
else
$(INTERNAL_OTA_PACKAGE_TARGET): backuptool := false
endif
$(INTERNAL_OTA_PACKAGE_TARGET): .KATI_IMPLICIT_OUTPUTS := $(INTERNAL_OTA_METADATA)
$(INTERNAL_OTA_PACKAGE_TARGET): $(BUILT_TARGET_FILES_PACKAGE) \
build/make/tools/releasetools/ota_from_target_files
@echo "Package OTA: $@"
$(call build-ota-package-target,$@,-k $(KEY_CERT_PAIR) --output_metadata_path $(INTERNAL_OTA_METADATA))
.PHONY: otapackage
otapackage: $(INTERNAL_OTA_PACKAGE_TARGET)
ifeq ($(BOARD_BUILD_RETROFIT_DYNAMIC_PARTITIONS_OTA_PACKAGE),true)
name := $(TARGET_PRODUCT)
ifeq ($(TARGET_BUILD_TYPE),debug)
name := $(name)_debug
endif
name := $(name)-ota-retrofit-$(FILE_NAME_TAG)
INTERNAL_OTA_RETROFIT_DYNAMIC_PARTITIONS_PACKAGE_TARGET := $(PRODUCT_OUT)/$(name).zip
$(INTERNAL_OTA_RETROFIT_DYNAMIC_PARTITIONS_PACKAGE_TARGET): KEY_CERT_PAIR := $(DEFAULT_KEY_CERT_PAIR)
ifeq ($(AB_OTA_UPDATER),true)
$(INTERNAL_OTA_RETROFIT_DYNAMIC_PARTITIONS_PACKAGE_TARGET): $(BRILLO_UPDATE_PAYLOAD)
else
$(INTERNAL_OTA_RETROFIT_DYNAMIC_PARTITIONS_PACKAGE_TARGET): $(BROTLI)
endif
$(INTERNAL_OTA_RETROFIT_DYNAMIC_PARTITIONS_PACKAGE_TARGET): $(BUILT_TARGET_FILES_PACKAGE) \
build/make/tools/releasetools/ota_from_target_files
@echo "Package OTA (retrofit dynamic partitions): $@"
$(call build-ota-package-target,$@,-k $(KEY_CERT_PAIR) --retrofit_dynamic_partitions)
.PHONY: otardppackage
otapackage otardppackage: $(INTERNAL_OTA_RETROFIT_DYNAMIC_PARTITIONS_PACKAGE_TARGET)
endif # BOARD_BUILD_RETROFIT_DYNAMIC_PARTITIONS_OTA_PACKAGE
endif # build_ota_package
重点关注前半部分，ifeq ($(build_ota_package),true)，也就是说这段代码的启用条件是，设置 build_ota_package为true，进一步搜索可以得到：
$ grep -arnw "build_ota_package" .
./build/make/core/Makefile:3540: # set build_ota_package, and allow opt-out below
./build/make/core/Makefile:3541: build_ota_package := true
./build/make/core/Makefile:3543: build_ota_package := false
./build/make/core/Makefile:3546: build_ota_package := false
./build/make/core/Makefile:3549: build_ota_package := false
./build/make/core/Makefile:3552: build_ota_package := false
./build/make/core/Makefile:3555: build_ota_package := false
./build/make/core/Makefile:3558: build_ota_package := false
./build/make/core/Makefile:3561: build_ota_package := false
./build/make/core/Makefile:4262:ifeq ($(build_ota_package),true)
./build/make/core/Makefile:4348:endif # build_ota_package
依然在这个文件中，3540行附近：
# -----------------------------------------------------------------
# host tools needed to build dist and OTA packages
# set build_ota_package, and allow opt-out below
build_ota_package := true
ifeq ($(TARGET_SKIP_OTA_PACKAGE),true)
build_ota_package := false
endif
ifneq (,$(filter address, $(SANITIZE_TARGET)))
build_ota_package := false
endif
ifeq ($(TARGET_PRODUCT),sdk)
build_ota_package := false
endif
ifneq ($(filter generic%,$(TARGET_DEVICE)),)
build_ota_package := false
endif
ifeq ($(TARGET_NO_KERNEL),true)
build_ota_package := false
endif
ifeq ($(recovery_fstab),)
build_ota_package := false
endif
ifeq ($(TARGET_BUILD_PDK),true)
build_ota_package := false
endif
# set build_otatools_package, and allow opt-out below
build_otatools_package := true
ifeq ($(TARGET_SKIP_OTATOOLS_PACKAGE),true)
build_otatools_package := false
endif
也就是说，默认生成ota，但满足条件时可以禁用，对于没有内核的设备，sdk编译目标，generic目标，或者设置变量TARGET_SKIP_OTA_PACKAGE为true的目标，是不必生成ota更新包的，那么到这里，解决方案已经很明确了，只需设置device中的BoardConfig.mk文件，修改或者增加一行TARGET_SKIP_OTA_PACKAGE := true 即可在构建时不生成ota！
