注：本篇文章是基于MSD648项目（AndroidTV）的prop进行说明。
Android版本：4.4.4
内核版本：3.10.86
1.生成build.prop
build.prop的生成是由make系统解析build/core/Makefile完成
1.1.Makefile生成build.prop的主要代码如下
$(INSTALLED_BUILD_PROP_TARGET): $(BUILDINFO_SH) $(INTERNAL_BUILD_ID_MAKEFILE) $(BUILD_SYSTEM)/version_defaults.mk $(system_prop_file) @echo Target buildinfo: $@ @mkdir -p $(dir $@) $(hide) TARGET_BUILD_TYPE="$(TARGET_BUILD_VARIANT)" TARGET_DEVICE="$(TARGET_DEVICE)" PRODUCT_NAME="$(TARGET_PRODUCT)" PRODUCT_BRAND="$(PRODUCT_BRAND)" PRODUCT_DEFAULT_LANGUAGE="$(call default-locale-language,$(PRODUCT_LOCALES))" PRODUCT_DEFAULT_REGION="$(call default-locale-region,$(PRODUCT_LOCALES))" PRODUCT_DEFAULT_WIFI_CHANNELS="$(PRODUCT_DEFAULT_WIFI_CHANNELS)" PRODUCT_MODEL="$(PRODUCT_MODEL)" PRODUCT_MANUFACTURER="$(PRODUCT_MANUFACTURER)" PRIVATE_BUILD_DESC="$(PRIVATE_BUILD_DESC)" BUILD_ID="$(BUILD_ID)" BUILD_DISPLAY_ID="$(BUILD_DISPLAY_ID)" BUILD_NUMBER="$(BUILD_NUMBER)" PLATFORM_VERSION="$(PLATFORM_VERSION)" PLATFORM_SDK_VERSION="$(PLATFORM_SDK_VERSION)" PLATFORM_VERSION_CODENAME="$(PLATFORM_VERSION_CODENAME)" BUILD_VERSION_TAGS="$(BUILD_VERSION_TAGS)" TARGET_BOOTLOADER_BOARD_NAME="$(TARGET_BOOTLOADER_BOARD_NAME)" BUILD_FINGERPRINT="$(BUILD_FINGERPRINT)" TARGET_BOARD_PLATFORM="$(TARGET_BOARD_PLATFORM)" TARGET_CPU_ABI="$(TARGET_CPU_ABI)" TARGET_CPU_ABI2="$(TARGET_CPU_ABI2)" TARGET_AAPT_CHARACTERISTICS="$(TARGET_AAPT_CHARACTERISTICS)" bash $(BUILDINFO_SH) > $@ $(hide) $(foreach file,$(system_prop_file), if [ -f "$(file)" ]; then echo "#" >> $@; echo Target buildinfo from: "$(file)"; echo "# from $(file)" >> $@; echo "#" >> $@; cat $(file) >> $@; fi;) $(if $(ADDITIONAL_BUILD_PROPERTIES), $(hide) echo >> $@; echo "#" >> $@; echo "# ADDITIONAL_BUILD_PROPERTIES" >> $@; echo "#" >> $@; ) $(hide) $(foreach line,$(ADDITIONAL_BUILD_PROPERTIES), echo "$(line)" >> $@;) $(hide) build/tools/post_process_props.py $@ build_desc :=
1.2.目标文件为$(INSTALLED_BUILD_PROP_TARGET)，其定义为：
INSTALLED_BUILD_PROP_TARGET := $(TARGET_OUT)/build.prop
1.3.首先对属性进行赋值，如BUILD_ID="$(BUILD_ID)"，最后执行bash脚本：bash $(BUILDINFO_SH) > $@，其定义为
BUILDINFO_SH := build/tools/buildinfo.sh
1.4.开始执行sh脚本中的内容
#!/bin/bash echo "# begin build properties" echo "# autogenerated by buildinfo.sh" echo "ro.build.id=$BUILD_ID" echo "ro.build.display.id=$BUILD_DISPLAY_ID" echo "ro.build.version.incremental=$BUILD_NUMBER" echo "ro.build.version.sdk=$PLATFORM_SDK_VERSION" echo "ro.build.version.codename=$PLATFORM_VERSION_CODENAME" echo "ro.build.version.release=$PLATFORM_VERSION" echo "ro.build.date=`date`" echo "ro.build.date.utc=`date +%s`" echo "ro.build.type=$TARGET_BUILD_TYPE" echo "ro.build.user=$USER" echo "ro.build.host=`hostname`" echo "ro.build.tags=$BUILD_VERSION_TAGS" echo "ro.product.model=$PRODUCT_MODEL" echo "ro.product.brand=$PRODUCT_BRAND" echo "ro.product.name=$PRODUCT_NAME" echo "ro.product.device=$TARGET_DEVICE" echo "ro.product.board=$TARGET_BOOTLOADER_BOARD_NAME" echo "ro.product.cpu.abi=$TARGET_CPU_ABI" if [ -n "$TARGET_CPU_ABI2" ] ; then echo "ro.product.cpu.abi2=$TARGET_CPU_ABI2" fi echo "ro.product.manufacturer=$PRODUCT_MANUFACTURER" if [ -n "$PRODUCT_DEFAULT_LANGUAGE" ] ; then echo "ro.product.locale.language=$PRODUCT_DEFAULT_LANGUAGE" fi if [ -n "$PRODUCT_DEFAULT_REGION" ] ; then echo "ro.product.locale.region=$PRODUCT_DEFAULT_REGION" fi echo "ro.wifi.channels=$PRODUCT_DEFAULT_WIFI_CHANNELS" echo "ro.board.platform=$TARGET_BOARD_PLATFORM" echo "# ro.build.product is obsolete; use ro.product.device" echo "ro.build.product=$TARGET_DEVICE" echo "# Do not try to parse ro.build.description or .fingerprint" echo "ro.build.description=$PRIVATE_BUILD_DESC" echo "ro.build.fingerprint=$BUILD_FINGERPRINT" echo "ro.build.characteristics=$TARGET_AAPT_CHARACTERISTICS" echo "# end build properties"
1.5.最后追加余下的属性
$(hide) $(foreach file,$(system_prop_file), if [ -f "$(file)" ]; then echo "#" >> $@; echo Target buildinfo from: "$(file)"; echo "# from $(file)" >> $@; echo "#" >> $@; cat $(file) >> $@; fi;) $(if $(ADDITIONAL_BUILD_PROPERTIES), $(hide) echo >> $@; echo "#" >> $@; echo "# ADDITIONAL_BUILD_PROPERTIES" >> $@; echo "#" >> $@; ) $(hide) $(foreach line,$(ADDITIONAL_BUILD_PROPERTIES), echo "$(line)" >> $@;) $(hide) build/tools/post_process_props.py $@
其中system_prop_file定义：
ifdef TARGET_SYSTEM_PROP system_prop_file := $(TARGET_SYSTEM_PROP) else system_prop_file := $(wildcard $(TARGET_DEVICE_DIR)/system.prop) endif
即$(TARGET_DEVICE_DIR)/system.prop文件
到此，prop文件生成完毕！
2.对生成的build.prop的属性进行说明：
# begin build properties # autogenerated by buildinfo.sh ro.build.id=KTU84P #版本ID ro.build.display.id=aosp_almond-userdebug 4.4.4 KTU84P TVOS-04.19.010.02.06.Mooney test-keys #具体版本号 ro.build.version.incremental=TVOS-04.19.010.02.07.Mooney #版本增量说明 ro.build.version.sdk=19 #SDK版本 ro.build.version.codename=REL #版本代号 ro.build.version.release=4.4.4 #Android系统版本 ro.build.date=2017年 07月 13日 星期四 14:39:47 CST #编译时间 ro.build.date.utc=1499927987 #编译时间(UTC) ro.build.type=userdebug #编译类型(eng/user) ro.build.user=pngcui #编译者 ro.build.host=Sky-pngcui #编译机器名 ro.build.tags=test-keys #系统标记 ro.product.model=MSD6A648 #设备型号 ro.product.brand=MStar #设备品牌 ro.product.name=aosp_almond #产品名 ro.product.device=almond #采用的设备名 ro.product.board=almond #采用的主板名 ro.product.cpu.abi=armeabi-v7a #CPU版本 ro.product.cpu.abi2=armeabi #CPU品牌 ro.product.manufacturer=Skyworth-qx, Inc. #产品制造商 ro.product.locale.language=zh ro.product.locale.region=CN ro.wifi.channels= #无线局域网络的通信信道,空白表示自动识别 ro.board.platform=mooney #主板平台 # ro.build.product is obsolete; use ro.product.device ro.build.product=almond #设备名，已被废弃，使用ro.product.device # Do not try to parse ro.build.description or .fingerprint ro.build.description=aosp_almond-userdebug 4.4.4 KTU84P TVOS-04.19.010.02.06.Mooney test-keys #用户key ro.build.fingerprint=MStar/aosp_almond/almond:4.4.4/KTU84P/TVOS-04.19.010.02.06.Mooney:userdebug/test-keys #机身码 ro.build.characteristics=tv # end build properties
3.修改prop的属性的说明，需要对照build/tools/buildinfo.sh进行
3.1.ro.build.id属性(build/core/build_id.mk)
export BUILD_ID=8M648
3.2.ro.build.display.id(build/core/Makefile)
build_desc := $(TARGET_PRODUCT)-$(TARGET_BUILD_VARIANT) $(PLATFORM_VERSION) $(BUILD_ID) $(BUILD_NUMBER) $(BUILD_VERSION_TAGS) # Display parameters shown under Settings -> About Phone ifeq ($(TARGET_BUILD_VARIANT),user) # User builds should show: # release build number or branch.buld_number non-release builds # Dev. branches should have DISPLAY_BUILD_NUMBER set ifeq "true" "$(DISPLAY_BUILD_NUMBER)" BUILD_DISPLAY_ID := $(BUILD_ID).$(BUILD_NUMBER) $(BUILD_KEYS) else BUILD_DISPLAY_ID := $(BUILD_ID) $(BUILD_KEYS) endif else # Non-user builds should show detailed build information BUILD_DISPLAY_ID := $(build_desc) endif
3.3.ro.build.version.incremental(device/mstar/almond/BoardConfigCommon.mk)
BUILD_NUMBER := TVOS-04.19.010.02.07.Mooney
3.4.ro.product.model、ro.product.brand、ro.product.name、ro.product.device、ro.product.manufacturer(device/mstar/almond/aosp_almond.mk)
# Set those variables here to overwrite the inherited values. PRODUCT_NAME := aosp_almond PRODUCT_DEVICE := almond PRODUCT_BRAND := MStar PRODUCT_MODEL := MSD6A648 PRODUCT_MANUFACTURER := Skyworth-qx, Inc.
注：PRODUCT_DEVICE会决定device下目录的选择，故尽量不要更改
3.5.ro.build.description(build/core/Makefile)
build_desc := $(TARGET_PRODUCT)-$(TARGET_BUILD_VARIANT) $(PLATFORM_VERSION) $(BUILD_ID) $(BUILD_NUMBER) $(BUILD_VERSION_TAGS)
$(INSTALLED_BUILD_PROP_TARGET): PRIVATE_BUILD_DESC := $(build_desc)
3.6.ro.product.board(device/mstar/almond/BoardConfig.mk)
TARGET_BOOTLOADER_BOARD_NAME := almond
4.Android系统中Setting.apk中内核版本
packages/apps/Settings/src/com/android/settings/DeviceInfoSettings.java
1 private static final String FILENAME_PROC_VERSION = "/proc/version"; 2 private static final String KEY_KERNEL_VERSION = "kernel_version"; 3 4 @Override 5 public void onCreate(Bundle icicle) { 6 findPreference(KEY_KERNEL_VERSION).setSummary(getFormattedKernelVersion()); 7 } 8 9 public static String getFormattedKernelVersion() { 10 try { 11 return formatKernelVersion(readLine(FILENAME_PROC_VERSION)); 12 13 } catch (IOException e) { 14 Log.e(LOG_TAG, 15 "IO Exception when getting kernel version for Device Info screen", 16 e); 17 18 return "Unavailable"; 19 } 20 } 21 22 public static String formatKernelVersion(String rawKernelVersion) { 23 // Example (see tests for more): 24 // Linux version 3.0.31-g6fb96c9 (android-build@xxx.xxx.xxx.xxx.com) 25 // (gcc version 4.6.x-xxx 20120106 (prerelease) (GCC) ) #1 SMP PREEMPT 26 // Thu Jun 28 11:02:39 PDT 2012 27 28 final String PROC_VERSION_REGEX = 29 "Linux version (\S+) " + /* group 1: "3.0.31-g6fb96c9" */ 30 "\((\S+?)\) " + /* group 2: "x@y.com" (kernel builder) */ 31 "(?:\(gcc.+? \)) " + /* ignore: GCC version information */ 32 "(#\d+) " + /* group 3: "#1" */ 33 "(?:.*?)?" + /* ignore: optional SMP, PREEMPT, and any CONFIG_FLAGS */ 34 "((Sun|Mon|Tue|Wed|Thu|Fri|Sat).+)"; /* group 4: "Thu Jun 28 11:02:39 PDT 2012" */ 35 36 Matcher m = Pattern.compile(PROC_VERSION_REGEX).matcher(rawKernelVersion); 37 if (!m.matches()) { 38 Log.e(LOG_TAG, "Regex did not match on /proc/version: " + rawKernelVersion); 39 return "Unavailable"; 40 } else if (m.groupCount() < 4) { 41 Log.e(LOG_TAG, "Regex match on /proc/version only returned " + m.groupCount() 42 + " groups"); 43 return "Unavailable"; 44 } 45 return m.group(1) + " " + // 3.0.31-g6fb96c9 46 m.group(2) + " " + m.group(3) + " " + // x@y.com #1 47 m.group(4); // Thu Jun 28 11:02:39 PDT 2012 48 } 49
即从/proc/version文件中提取相应信息。