[General Questions and Answers] XiaoMigue:
FYI: I got your download. Thanks very much ^_^

Also, prior to watching your PM, I found a way for downloading the pan.baidu files without an account (I already had tampermonkey and an arab page had a script for so... just installed script -after reading what it does, of course-, visited page again, and hitting download just simply downloads it)

In any case, I managed to make a "fastboot flash system system.img" (with system.img extracted from update.app), amd mobile came up; needed to reconfigure it all, so i went again through all menus and so. But

WARNING - DON'T DO THIS

I activated the "Find phone" feature from huawei

WARNING - DON'T DO THIS

and that was a BIG mistake. I started again trying to setup google... and i broke it again (i think one of the "GMSInstallers out there I've tested makes an uninstall... but it uninstalls too much!). Mobile was booting, but it only showed a BLACK screen with navigation buttons, and pressing volume keys dropped down the volume menu (in chinese) and that was all. Okay, let's restore again... fastboot... WTF! "FAILED: Need to disable Phone finer first". But the f*** phone does not boot so I can not do that! nightmare begins. Again.

Solved, though. Steps:

- put mobile on fastboot mode (still unlocked, btw)

- Use HiSuite in PC for upgrading. It said "downloading"... uncompressiong...installing recovery...installing system...

- (yes, stock recovery, TWRP lost)

- Installation failed. WTF?!?!?!

- reset mobile; it starts usual boot animation, and then vibrates, and reboots automatically in stock recovery. I try to use it for download and setup upgrade. after download is complete, it fails to install

- Retry HiSuite. This time it ends telling "success". Reboot mobile again

- Again fails to boot. Again try the Wifi solution. This time, I reboot into recovery again, instead going to normal reboot. I do eery wipe I can. it works. Mobile boots again, as brand new mobile.

- I have version B201 with locked boot and stock recovery. But it works.

- There is an OTA ready; download it and install. First try fails (in recovery mode), second try works. Now I have the B210 version.

- I configure things again, and I go... let's install TWRP again in order to create backup (this time I won't forget to do so)

- First step: unlock bootloader again. Ok, it works. Oh, gosh... it makes a factory reset again (all configs done previously, lost).

- Configure all things again. I update all the apps ready to update. Now I can finish install of TWRP and make a full backup of mobile.

Now I'm going to install TWRP, make a full backup, and try to install only basic gapps in the way i've found in other webs: (make a google search for reference): "

".

If not, I will try to get ROM for any of Huawei Y7 Prime TRT-AL53, TRT-L21A, or other TRT (for example TRT-LX1, TRT-LX3, Y7 2017, Nova Lite+, they all have 2Gb/16Gb but other specs are the same... and important thing is they are nougat 7.0/emui 5.1 as my last update -B210-, so google apps in that rom may be compatible)

I have it in a mega link, if you like them:

TRT-AL00B102_Android+7.0_EMUI+5.0.rar

I reccomend you using HiSuite, if you don't mind resetting mobile to original state (bye bye pics, videos, apps, and so on, unless you have them in cloud). On the other hand, I did not tested this with TWRP nor huawei's default recovery, but this update.zip is the file HiSuite has downloaded for trying to restore my mobile. You can dow many things with it:

+ Extract system.img and then make a fastboot flash sytem system.img (i did when mobile still had bootloader unlocked, and it worked, leaving my data live)

+ copy dload folder with update.app inside to the root folder of a microSD and put the microSD inside mobile; then try to boot into emergency mode (up+down) or in recovery and install it. I have not tried this method.

Good luck.