Android 5.0最终推出了正式版，今天也及时刷到了Android5.0 (LRX21O)，官方链接：https://developers.google.com/android/nexus/images
镜像下载地址：https://dl.google.com/dl/android/aosp/hammerhead-lrx21o-factory-01315e08.tgz。MD5：761667f1ddaf4e38d4792136df4ab927。SHA-1:01315e08c7f282452b5eba0606dd5a2d5274edde。
刷机过程例如以下：
1、解压下载好的.tgz包
2、解压faseboot包。并将里面的内容拷贝到解压好的tgz包的文件文件夹中
3、手机关机，同一时候按住开机键和音量-
4、双击运行flash-all.bat。运行过程中出现了问题：archive does not contain ‘boot.sig‘。archive does not contain ‘recovery.sig‘；failed to allocate 717308456 bytes；error: update package missing system.img。
解决方法：编辑flash-all.bat。凝视掉“::fastboot -w update image-hammerhead-lrx21o.zip”。即在此行前加“::”，将image-hammerhead-lrx21o.zip解压开。然后添加下面代码：
fastboot flash boot boot.img
fastboot flash cache cache.img
fastboot flash recovery recovery.img
fastboot flash system system.img
fastboot flash userdata userdata.img
fastboot reboot
总体代码改动为：
@ECHO OFF
:: Copyright 2012 The Android Open Source Project
::
:: Licensed under the Apache License, Version 2.0 (the "License");
:: you may not use this file except in compliance with the License.
:: You may obtain a copy of the License at
::
:: http://www.apache.org/licenses/LICENSE-2.0
::
:: Unless required by applicable law or agreed to in writing, software
:: distributed under the License is distributed on an "AS IS" BASIS,
:: WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
:: See the License for the specific language governing permissions and
:: limitations under the License.
PATH=%PATH%;"%SYSTEMROOT%\System32"
fastboot flash bootloader bootloader-hammerhead-hhz12d.img
fastboot reboot-bootloader
ping -n 5 127.0.0.1 >nul
fastboot flash radio radio-hammerhead-m8974a-2.0.50.2.21.img
fastboot reboot-bootloader
ping -n 5 127.0.0.1 >nul
::fastboot -w update image-hammerhead-lrx21o.zip
fastboot flash boot boot.img
fastboot flash cache cache.img
fastboot flash recovery recovery.img
fastboot flash system system.img
fastboot flash userdata userdata.img
fastboot reboot
echo Press any key to exit...
pause >nul
exit
再次双击运行。成功刷入Android 5.0。