[Android General] AeonFlux1603:
LineageOS 14.1 Port ROM

Lenovo Tab 3 8"/TB3-850F

•WARNING:

You are installing this custom Android ROM at your own discretion and risk. If you are unclear on anything, please stop and do some research before proceeding further. This is not a Q & A thread, so please post comments on topic with subject matter relating directly to this ROM. I will not be held responsible for devices which become bricked or damaged as a result of installing this ROM. You are encouraged to read and re-read the OP prior to installing this ROM on your device. Please visit this thread for now to make general inquiries about this ROM or about any other questions or issues you may have regarding the 850F. Either myself or XDA Senior Member [MENTION=7550078]pndwal[/MENTION], who is very knowledgeable about this device and Android in general, will try to address your questions. https://xdaforums.com/android/general/guide-lenovo-tab3-8-tb3-850f-t3559786 User input and feedback are essential in making improvements, fixing bugs, and in helping development for this device to continue to evolve.

Any skilled devs interested in contributing in any way to development for the 860F, please use the above thread to contact [MENTION=7550078]pndwal[/MENTION] and coordinate with him in that area.

I am not a developer, nor did I contribute to the porting of this LineageOS 14.1 custom ROM for the TB3-850F. I merely packaged up the files, added GApps Pico, made a few minor tweaks, and created a TWRP flashable zip installer for this ROM. Please do not request updates or make ETA type inquiries on this thread. Whether or not this ROM will be maintained is still up in the air. Please give any and all credit to the individuals I have listed below under Mentions & Credits.

LineageOS 14.1 is a free, aftermarket distribution of Android 7.1.2 Nougat, which is designed to increase performance and reliability over stock Android for your device.

LineageOS is based on the Android Open Source Project with extra contributions from many individuals within the Android community. Although this particular LineageOS build does have GApps Pico preinstalled, it can be used without any need to have any Google application installed. LineageOS does still include various hardware specific code, which is nonetheless slowly being open-sourced anyway.

SOURCES:

LineageOS Source Code: https://github.com/LineageOS

Kernel Source Code: https://support.lenovo.com/us/en/downloads/ds112711

LineageOS Gerrit Code Review: https://review.lineageos.org/q/status:open

FEATURES & SPECS:

•LineageOS Version: 14.1

•Android Base Version: 7.1.2_r8 Nougat

•Build ID: N2G470

•SDK Version: 25

•Build Date: May 15, 2017

•Security Patch Level: May 5, 2017

•Kernel Version: 3.18.19 (mods by [MENTION=8548258]wezroot2k[/MENTION])

•LineageOS API Level: Guava (7)

•GApps Pico Pre-installed

•Insecure Boot Image Support

•Force Encryption Disabled (Opt-Encrypt)

•AVB/dm-verity Disabled

•Fully Deodexed

•Fully Zip-aligned

•User Opt Root or Non-Root

•Status: Unofficial/Stable

WORKING:

•Booting

•WiFi

•Bluetooth

•Graphics/Video Playback

•Audio

•GPS/Location Services

•GApps

•Magisk Universal Systemless Interface

BUGS:

I am presently working on Settings UI to omit the mobile networks/telephony entries. These are present because this ROM was originally a smartphone port. Otherwise, please feel free to submit a proper bug report or, at a minimum, a clear description of the bug or instability, including screenshots if possible.

A bug has been reported for apps that require superuser permissions (Greenify, root file managers, etc), and I have determined that installing the latest Magisk systemless root will alleviate that bug.

Upon initial boot, during setup, you may experience an issue with Setup Wizard force closing. I have posted a quick workaround for this below under the Installation Instructions heading.

REQUIREMENTS:

You need an unlocked bootloader and TWRP custom recovery installed. If you need help with either of these topics, please visit this thread for guidance: https://xdaforums.com/android/general/guide-lenovo-tab3-8-tb3-850f-t3559786

INSTALLATION INSTRUCTIONS:

1. Download the ROM zip from the below download link and save it to your device storage...

2. Boot your device into TWRP recovery mode...

3. Wipe Data, Cache & Dalvik/ART (my installer automatically formats the /system partition)...

4. Select Install, navigate to saved location of the ROM zip, select it and swipe the action bar to begin installation...

5. Reboot system (installation will take around three minutes).

*Because this ROM is fully deodexed, first boot can take several minutes to complete while the Dalvik/ART directories are being written for the first time. The second and subsequent boot times will be much faster. Also, on first boot, select your language then choose SKIP on the Insert SIM Card screen. You will then be prompted to set up your device as new or copy data from another device as part of setup. At this stage, if the Setup Wizard force closes, swipe down from the top of the screen to access Quick Settings and go ahead and connect to a WLAN/WiFi network. Now, go back to the previous screen and Setup Wizard should function normally and allow you to proceed with setup of your device. I am presently working on removing SIM/Mobile Network settings on this device, so hopefully this will be fixed soon, and a true WiFi-only tablet port will be yielded.

**As mentioned supra, this ROM is packaged with GApps Pico, which provides the bare bones minimum for Google Play functionality. If you want a GApps package other than the one preinstalled, visit https://opengapps.org/, choose ARM64, Android 7.1, and select your preferred package. Simply install the GApps package after Step 4 above. If you want root, visit the official Magisk release & announcement thread here https://xdaforums.com/apps/magisk/official-magisk-v7-universal-systemless-t3473445, and download the latest Magisk Manager apk. Install the apk, go to Developer Options and enable Apps & ADB in the root options menu. Open Magisk Manager, select Install, pick the direct install option, and systemless root will be installed via patched boot image. Reboot and systemless root should be properly installed & stable. Be sure and hit the Thanks button on [MENTION=4470081]topjohnwu[/MENTION]'s thread if you use Magisk.

MENTIONS & CREDITS:

This port was made possible by a number of individuals both here at XDA and abroad:

- Credit goes to 4PDA (Russian Development site) member chipa76 for the original TB3-850M port, and to 4PDA member al_rus for his contributions to, and for posting that port.

- Credit and thanks for the breakthrough moment for TB3-850F users must go to XDA member [MENTION=8548258]wezroot2k[/MENTION] who, after others tried for many months, was finally able to stabilise this ROM for our device by recompiling the ported boot image with TB3-850F stock kernel. Also, he has worked on tweaks to streamline the ROM for TB3-850F.

- TWRP flashable ROM package as well as some tweaks to streamline the ROM for TB3-850F have been made by the OP, [MENTION=9720847]AeonFlux1603[/MENTION], who will continue to work on a few further improvements, insomuch as spare time will allow

- Thanks to XDA Senior Member [MENTION=7550078]pndwal[/MENTION] for his dedication to this device and for passing on suggestions from the 4PDA Devs regarding the adopted method of stabilising ROM for TB3-850F.

- Last but not least, thanks and credit goes to the entire LineageOS Dev Team for making this custom aftermarket distribution of Android possible for low-grade, mid-grade & flagship devices alike.

DOWNLOAD LINK:

LineageOS 14.1 for TB3-850F: https://drive.google.com/file/d/1bbpwyvP_S4k1PJaLa6RN3dFDF8UYEcNj/view