不解锁，不 Root，降级系统用 Google

本文应 XDA 大神 duraaraa需求，将其发布的简化版降级方式翻译成中文供大家使用。

原贴地址：http://forum.xda-developers.com/mate-9/how-to/beta-test-b109sp01-downgrade-simplified-t3506025

降级方式如下：

本方法可将任意Mate 9 任意版本系统降级到带框架的 B109SP01 版本。


**请严格按照本帖中的方法进行降级！降级有风险，请谨慎使用！本文不对降级造成的任意不良后果负责！


第一步：
>进入路由器的管理员设置界面。找到 WAN DNS Server（广域网 DNS 服务器） 页面，并将其设置为 133.130.88.119.
>将手机和电脑连接到这个 WIFI，并用浏览器访问网址http://query.hicloud.com:80/
>如果可以成功访问，说明 DNS 设置正确，请继续下面的步骤。


第二步：
--这一步比较复杂，请一定仔细阅读--
>用 USB 线连接手机和电脑。
**请一定不要把 USB 线从电脑上拔下来**
>在手机中进入设置》高级设置》备份和重置》恢复出厂设定。
>在恢复出场设定完成后，关机，然后按电源键和增加声音键，进入 ERecovery 模式。

第三步：
>进入 eRecovery 模式后，选择下载并恢复设备。如果你的网络设置符合第一步中的描述，将可以看到系统会自动下载MHA-AL00C00B106 版本。
>如果看到下载的是 MHA-AL00C00B109SP01，请取消升级，并再次重复恢复出场设定，再次进入 eRecovery 模式进行下载恢复。
>如果你看到的不是上述的两个版本，那说明要么你 DNS 没设置好，要么我的服务器出问题了。


第四步：
Step 4:
>MHA-AL00C00B106 在下载完毕之后会自动进行安装。
**重要提醒：MHA-AL00C00B106 在安装完成之后，不要直接启动进入系统，这里必须进入 eRecovery 模式！**
>千万记得在安装的时候一定要盯着手机，MHA-AL00C00B106 在安装完成后会重启，这时候一定要按住音量向上键进入 eRecovery 模式，否则前功尽弃，要从头再来。
** 再次提醒：安装快完成的时候就按住音量向上键，这样才能在自动重启后进入 ERecovery 模式！ **

第五步：
>进入 ERecovery 模式之后，请查看 recovery 版本，如果一切没错，这里会显示 B109SP01。
>如果显示 B106，那就取消，然后重启再进入 ERecovery 模式。
>如果显示的是其他东西，那么要么是 DNS 有问题，要么我服务器有问题。
> B109SP01 包很小，很快就可以下载完。更新完成之后，就可以重启手机，系统现在就运行在带框架的 B109SP01 版本了。

第六步：
>进入华为软件商店，下载 Google Play，然后享受你的带框架 Mate 9 吧！

*附上英文原文：
To downgrade from any version to B109SP01 with Google framework.

MAKE SURE YOU FOLLOW THE INSTRUCTIONS EXACTLY! I CANNOT BE RESPONSIBLE FOR BRICKED DEVICES!

Step 1: Go to the admin settings of your wifi router. Find the WAN DNS Server setting, and set it to 133.130.88.119 Connect to your wifi with a phone or computer, and try to access http://query.hicloud.com:80/ in a browser. If it says Successful. Please proceed. you know your DNS settings are correct.

Step 2:
--THIS IS TRICKY SO READ CAREFULLY!--
Plug the USB cable from your phone to your computer.
**MAKE SURE THE USB CABLE STAYS PLUGGED IN TO YOUR COMPUTER**
On your phone, go to Settings, Advanced Settings, Backup & Reset, Factory data reset. When the factory data reset finishes, you will need to hold the volume up key as the phone reboots, to get directly into eRecovery mode.

Step 3:
You are now in eRecovery mode. Choose to download and restore the phone. If your network settings are correct, you will see the version is MHA-AL00C00B106 which the eRecovery is downloading. If you see MHA-AL00C00B109SP01, please cancel the update, do a factory restore again, and try the update again. If you see anything else as the version, something is wrong with your DNS settings, or with my server.

Step 4:
Once the MHA-AL00C00B106 download has completed, it will install.
** VERY IMPORTANT. WHEN THE INSTALL IS FINISHED, YOU MUST HOLD THE VOLUME UP KEY TO GET BACK INTO eRECOVERY. DO NOT ATTEMPT TO BOOT B106!! **
It is EXTREMELY important you watch your phone when the recovery finishes. The phone will reboot automatically. Make sure you are holding the volume up key when this automatic reboot happens to go immediately back to eRecovery. If you are not, your phone will temporarily boot loop and you will have to go back to B125 and start over.
** AGAIN, HOLD THE VOLUME UP KEY WHEN THE RESTORE IS FINISHING SO IT REBOOTS INTO eRECOVERY MODE. VERY IMPORTANT **

Step 5: You are back in eRecovery mode. Great! Now, when you check for the recovery version, it will show B109SP01. If it shows B106, please cancel and reboot back to eRecovery and try again. If it shows anything else, something is wrong with your DNS settings, or with my server. The B109SP01 download is much smaller than the B106 download, and it will finish in a few moments. When it´s finished, you can boot up your phone, and it will be on B109SP01!

Step 6: Go to the HiApp store, and get Google Play. Congratulations, you are finished!