[Alcatel Idol 4S Questions & Answers] DeckerSU:
How to install TWRP recovery on Idol 4 6055?

1. Go to the Sahara & Firehose Test (Alcatel Flasher oncoming ...) thread and carefully read the topic. After that download the latest version of tool and unpack it in the separate folder.

2. Install Alcatel Qualcomm drivers. Better way to do it is to install Mobile Upgrade Q utility from Alcatel's support section. It will install all needed drivers automatically.

3. Turn your phone in download mode. To do this connect the powered off phone to PC via USB-cable and hold Volume Up + Volume Down + Power buttons until you get this screen:

After - press Volume up button to enter download mode.

4. Download the TWRP recovery image from here - twrp_recovery_idol4_6055.img. This recovery is based on latest 7.0-branch sources from Omni git and fully support (i spent a lot of time time to get this work) of userdata partition decryption. So, if your phone is protected by password or digital PIN - you will be able access your data from TWRP, also you will be able access to Adopted Storage encrypted flash. For all users who interesting - here is a device tree for TWRP building on 6055.

5. Launch Sahara & Firehose Test:

6. Choose your device model (1), in our case this is Alcatel Idol 4 5.2" (OT-6055).

7. Press Detect (2) button, program will detect all COM-ports in system. Choose COM-port (3) with the name Qualcomm HS-USB QDLoader 9008 (in your case name of device can be different, it depends on version of your drivers, you should choose COM-port with the name containing 9008).

8. Press NPRG (4) button to load Firehose Programmer. If all succeded, in the log window (5) you should see something like that:

18.09.2016 2:43:52: Start Download NPRG ....
18.09.2016 2:43:52: offset[0],len[52]
...
18.09.2016 2:43:52: offset[102400],len[4096]
18.09.2016 2:43:52: offset[106496],len[3044]
18.09.2016 2:43:52: SAHARA_END_IMAGE_TX_ID received

0000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 *................*

18.09.2016 2:43:53: Send done command

0000: 06 00 00 00 0C 00 00 00 00 00 00 00 *............ *

9. Press Get GPT (6) button. As a result you should see partition table (7). If filling partition table succeded - you can continue. All next steps required filled GPT.

10. According to Sahara & Firehose Test (Alcatel Flasher) manual - before you proceed any writing procedure (before you try to flash any partition) it's strongly recommended to test read function. First of all let's try to backup our stock recovery. To do this in partition table (7) check the checkbox on recovery partition and set-up the file name where it'll be saved. For example, name can be - recovery.img. Do backup by pressing (9) Read button. If backup is succeded you should get the recovery.img file containing your stock recovery. Size of this file for Idol 4 should be near ~64 Mb.

11. If previous step is done and you get backup of your recovery image, now you can flash TWRP. Choose in (10) twrp_recovery_idol4_6055.img image and press (11) Write button.

12. After you press Write you will see a "last warning" choose "No" if you wanna flash selected partition, or "Yes" - to cancel the operation. If you press "No" flasher will immediatelly starts to write selected partitions into a phone.

Congratz ! Now you was flashed TWRP recovery. There is no automatically reboot the phone after flashing. To enter TWRP just hold Volume Up button and press Power. Wait for TWRP recovery is loading, when you see TWRP logo - release Volume Up button.

Hope this small manual will help you ... It also available in other languages. Check this for russian version, or this for french version.

How to install root on Idol 4 6055?

Flash the latest SuperSU zip from chainfire.eu via TWRP in systemless mode.

Useful links:

Alcatel Idol 4 6055K. Working TWRP. World first ;) - proof video. Demo of running TWRP recovery on Idol 4 6055.

Sahara & Firehose Test (Alcatel Flasher oncoming ...) - flasher-related thread on XDA.

FAQ

Q. I have a Idol 4 6055U from Cricket. Is this instruction work on Cricket devices?

A. Unfortunatelly no, 6055U from Cricket little bit different from others (6055K, 6055P, ...), so, if u have device from Cricket - you will not able to use this. Cricket's 6055U is not supported current.

Q. I have a bootloop after exit from TWRP, what should i do?

A. This is known problem, boot in TWRP and wipe cache and dalvik cache from it. Also, make sure that you used latests SuperSU.zip from chainfire.eu ... Current latest version is a SR1-SuperSU-v2.78-SR1-20160915123031.zip.