[ZTE Axon 7 Questions & Answers] dnlilas:
[MENTION=8254168]Whoooo?[/MENTION]

This guide is suited for you:

https://xdaforums.com/axon-7/how-to/guide-install-twrp-unlock-bl-flash-t3517379

There are some steps that could be simplified, but there are all OK.

Personally I think A2017G is not working well with MiFlash (several problems: difficulty to recognize the phone, MiFlash software is touchy,

many versions, need time window in EDL mode, receive hello packet error etc...). The above guide did not mention MiFlash neither.

Do not use Qualcomm bulk drivers that gives you Qualcomm HS-USB QDLoader 9008 for use with MiFlash.

Recommendation: Use Zadig (http://zadig.akeo.ie/) to have WinUSB driver for QUSB_BULK. So probably you need to uninstall the driver first ("adb reboot edl", then start Windows

device manager, Uninstall and delete the driver Qualcomm HS-USB QDLoader 9008). Unplug and replug the phone, it will appear under unknown device QUSB_BULK.

Run zadig to install driver (select the WinUSB driver) => the phone will appear OK under USB peripheral:

it will be able to receive command from axon7tool in EDL mode.

To answer your questions:

>With a 2017G (6.0MM B08) is it possible to

>- Unlock the bootloader first without using tenfar's 3.0.2 TWRP?

Yes you can do that, before installing TWRP. You can also as in the guide, install TWRP first, then unlock bootloader.

Note: if you choose to unlock the bootloader first, then you can directly install latest TWRP 3.1.1-0 (unsigned) without the need to install the signed tenfar's TWRP first as with locked bootloader, then upgrade TWRP to 3.1.1-0.

The guide is applicable for any version of MM up to V1.0.0B11.

>- Which Unlock file should I use? The first one? Or can I use the generic (second) one with MiFlash or TWRP only?

If you follow the above mentioned guide, you do not need any of these files.

>- If that works, did you simply go Advanced Options<Flash boot/bootloader/modem/recovery<choose recovery partition<select C:\Axon7Development\Axon7Toolkit\twrp\twrp-3.1.0-ailsa_ii.img with the Toolkit? (or did you e.g. have to install adb 1.4.2 first to get twrp on the device via adb)

You want to install TWRP? Follow the mentioned guide.

My own remarks on top of the guide :

Part A) step 15): Go to Device Manager on your pc and verify your Axon 7 is listed as "QUSB_BULK".

You should see the phone correctly installed thanks to Zadig and not unknown device with yellow cross.

Steps 16 to 19 could be skipped (since you can have full ROM image to restore boot/recovery if needed: https://xdaforums.com/axon-7/how-to/download-center-factory-images-ota-t3606547).

Step 20) In command, type "axon7tool -w recovery": this means you should have in the directory the file recovery.bin which is exact copy of twrp_rec_tenfar.img.

Attention to enable file extension display in Windows.

Part B) steps 1 to 13 could be skipped and replaced by:

Boot into TWRP : either "adb reboot recovery" or Power + Vol Up.

Inside TWRP, flash TWRP_UnlockBootloaderPackage_by_DrakenFX.zip

https://androidfilehost.com/?fid=24723757092307343

to enable fastboot (this patch aboot and fastboot so fastboot command to unlock bootloader will be accepterd).

Then follow steps 14 to 18.

Note: if you do not enter TWRP immediately in step 17) after unlock procedure, maybe you will boot to system (Android),

and probably password asked, cancel, boot to TWRP and format data (ext4fs): Power + Volume Up (or if you can boot to system, type command "adb reboot recovery").

Note: important: in TWRP do not allow system modifications. If you allow system modifications and not flash no-verity-opt-encrypt-5.1.zip

or not flash SuperSU 2.79 immediately, you will get in trouble at boot.

Now update TWRP (if not yet done): boot in to TWRP, Install, Image, choose latest TWRP 3.1.1-0 taken from

https://eu.dl.twrp.me/ailsa_ii/

File twrp-3.1.1-0-ailsa_ii.img

md5 94018d5d92a89657ccd0420a0464859b

then check "boot partition".

Reboot to recovery and check that TWRP is the latest.

Done. Now with unlocked bootloader and TWRP latest version, you can do anything with the phone

(backup/restore, install latest stock Marshmallow or Nougat with TWRP https://xdaforums.com/axon-7/development/stock-rom-a2017g-twrp-flashable-images-t3599069,

flash SuperSU2.79 for root, install custon ROM with TWRP...).