How to install LineageOS 14.1 on Nexus 7 2012

Before proceding to this step, ensure that your device is actually a Nexus 7 2012. It is noticeably different to Nexus 7 2013 because the first only has front camera and the later has two, one on each side.

Developers use codename ‘grouper’ to identify Nexus 7 2012. So they will be synonyms in some documentations, including this post.

The highest Android version that is supported by Nexus 7 2012 is Androird 5.1.1 (Lollipop). Latest LineageOS version for this device for the time being is 14.1, which corresponds to Android 7.1 (Nougat). So this is a way to upgrade Nexus 7 (2012) OS, out of Google support.

Theoretically you can install a ROM Manager in Android the two ways below. This tutorial only considers second option as I did not succedeed in rooting successfully (SuperSU app crashed while running Android):

1. By installing and running Play Store apps in a rooted device
2. By flashing ROM managers directly into recovery mode

When performing these operations you may lose your phone. Apply these steps under your own risks.

Detailed instruction

1. Ensure developer mode is enabled in tablet

Check if you can find ‘Developers options’ in ‘Settings’ > ‘System’.

If it cannot be found, go to ‘Settings’ > ‘System’  > ‘About tablet’ and tap 7 times on ‘Version’.

2. Download LineageOS ROM

Download from link below:

lineage-14.1-20171122-UNOFFICIAL-aaopt-grouper.zip (AndroidFileHost)

3. Download GApps (optional)

GApps is the name given to a package that group Google basic applications, like Play Store. You may be interested in getting access to Google catalog app, so this step may interest you.

Look for corresponding version of GApps for your device (in case of Nexus 7 2012, Lineage 14.1 ARM/32-bit) and desired software variant (that range from minimum to full installations) and download it to your computer.

https://opengapps.org/

4. Install a custom recovery app

Read this post about how to install generic custom recovery manager.

But please also find below the specific instructions for Nexus 7 2012 to download custom recovery images and GApps:

Disclaimer: I do not support unconditionally neither of the ROM Manager applications, but this time I am recommending TWRP because it was the only one that worked for me.

TWRP (recommended!)

There is one specific page for Asus Nexus 7 2012 / grouper in TWRP web. Download latest version from it:

TWRP 3.2.3.0 grouper (version that worked for me)

TWRP 3.2.1. generic (it did not work on Nexus 7 (2012), as it does not load main screen in recovery mode)

ClockworkMod Recovery (CWM) (not recommended)

Unfortunately, CWM removed from his web the image download page (broken link). It looks as they want to encourage rooted app installation method.

However other mirros keeps download links:

6.0.5.1 (it did not work on Nexus 7 (2012), as it does not load main screen)

6.0.2.3 (it worked for me, but I got errors on Android startup after installing LineageOS 14.1+OpenGApps)

OpenGApps

To download the correct version from OpenGApps web you need to identify what you need:

• Platform: ARM. Nexus 7 (2012) platform is ARM. So there are no more possibilities about this.
• Android: 7.1. As this tutorial is for Lineage 14.01 and it corresponds to Android 7.1, this is the one.
• Variant: here you can choose what you prefer, from aroma (full installation) to pico (lightest).

In my case, I downloaded ‘open_gapps-arm-7.1-pico-20181101.zip’ and it worked fine.

5. Connect tablet to computer

Use an USB cable.

6. Place downloaded LineageOS ROM into tablet

You can either:

a. Copy to root folder using application like ‘Android transfer file’. Your tablet must be configured in USB MTP mode.

b. Alternatively, you can run this code:

./adb push /Users/pablo/Downloads/<rom> /sdcard/<rom>

7. Place downloaded GApps into tablet (optional)

In the same way as previous step, copy these two files into the same root folder:

• GApps ROM file: open_gapps-arm-7.1-pico-20181101.zip

CWT:

You may need to add also this text file to avoid a insufficient space error:

• Text file: gapps-config-grouper.txt

With default settings it will give an error about insufficient space. To avoid that, first copy this gapps-config-grouper.txt file, perhaps edit it to your taste (instructions here), then copy to the device in the same directory as the opengapps zip. The opengapps updater-script will look for it there when you install opengapps.

8. Run recovery mode

Run this command:

./adb reboot bootloader

Then choose option ‘Recovery mode’ from bootloader.

9. Init custom recovery

CWT:

Just wait.

TWRP:

Swype “Swype to Allow Modifications”.

10. Wipe data, cache and delvik cache

CWM:

Tap Main Menu > “Wipe data/factory reset” > Yes.

Tap Main Menu > “Wipe cache partition” > Yes.

Tap Main Menu > “Advance” > “Delvik cache” > Yes.

TWRP:

Tap Main Menu > “Wipe” > Swipe “Swype to Factory Reset”

11. Make a Nandroid backup

At this time you should perform a backup from

I did not, but I should. So I am not providing the instructions, but you can find them in other posts like the one below:

http://www.androidtipsandhacks.com/root/twrp-the-complete-guide-to-using-recovery-on-android/

12. Install LineageOS ROM using custom recovery

CWM:

Tap ‘install zip from sdcard’

Tap ‘choose zip from sdcard’

Tap ‘0′ to access the /sdcard area

Tap ‘lineage-14.1-20171122_224807-UNOFFICIAL-aaopt-grouper.zip’ (filename in my case)

TWRP:

Main menu > ‘Install’ > ‘Install image’

Take advantage and click on “Add more Zips” and just add the .zip file described in next step

Swype “Swype to configure”

13. Install GApps (optional)

CWM:

Select ‘choose zip from sdcard’.

Tap ‘0′ to access the /sdcard area

Tap ‘open_gapps-arm-7.1-pico-20181101.zip’ (filename in my case)

TWRP:

Main menu > ‘Install’ > ‘Install image’

Tap ‘open_gapps-arm-7.1-pico-20181101.zip’ (filename in my case)

14. Reboot

First reboot will take some minutes, so please have patient once reboot has started.

CWT:

I selected Main menu > ‘Reboot’. You may got a message “Root access possibly lost. Fix? THIS CANNOT BE UNDONE”. If this is the case, select ‘Yes – Fix’

TWRP:

Click on ‘Reboot System’.

It will ask if you want to install Official TWRP App. In my case I clicked on ‘Do Not Install’.

15. Solve Setup Wizard error

You may get an error from Setup Wizard when openning tablet: ‘Setup Wizard keeps stopping’. It happened to me when installing LOS 14.1+GApps with CWT

I applied solutions from forums but none of them worked to me. Final solutions was to repeat installation using TWRP, and there was no error at all.

16. Delete installation files

Enter adb shell:

./adb shell

Ensure that installation files keep being in /sdcard/ folder:

ls /sdcard/

Remove both LinageOS and GApps zips. For example:

rm /sdcard/lineage-14.1-20171122_224807-UNOFFICIAL-aaopt-grouper.zip

rm /sdcard/open_gapps-arm-7.1-pico-20181101.zip

Exit shell:

exit

External References

• “LineageOS 14.1 for Nexus 7 2012” by aaopt
• “Update Nexus 7 2012 to Android 7.1.2 LineageOS 14.1 Nougat Custom Firmware” by Saad Khan
• “TWRP: the complete guide to using Recovery on Android” by Android Tips & Hacks