1、通过源码查看 Android 版本

路径：build/core/version_defaults.mk

PLATFORM_VERSION := 5.1.1

2、通过编译时终端输出查看

============================================

PLATFORM_VERSION_CODENAME=REL

PLATFORM_VERSION=5.1.1

TARGET_PRODUCT=rk3288

TARGET_BUILD_VARIANT=eng

TARGET_BUILD_TYPE=release

TARGET_BUILD_APPS=

TARGET_ARCH=arm

TARGET_ARCH_VARIANT=armv7-a-neon

TARGET_CPU_VARIANT=cortex-a15

TARGET_2ND_ARCH=

TARGET_2ND_ARCH_VARIANT=

TARGET_2ND_CPU_VARIANT=

HOST_ARCH=x86_64

HOST_OS=linux

HOST_OS_EXTRA=Linux-3.13.0-39-generic-x86_64-with-Ubuntu-14.04-trusty

HOST_BUILD_TYPE=release

BUILD_ID=LMY49F

OUT_DIR=out

============================================

3、通过编译后的输出文件查看

路径：out/target/product/xxx/system/build.prop

ro.build.version.release=5.1.1