Installing CyanogenMod 12.1 on Nexus 7 (2012 version) (a.k.a. “grouper”)

This entry is just to remember steps that I have followed to install CyanogenMod 12.1 on my Nexus 7 (2012).
This would be the previous point to be able to make my tablet backups using BackupPC (you can check this link Nexus 7 & BackupPC).
The following information is extracted from this guide.
First of all, some packages need to be installed in the PC which is going to be used to connect with your tablet, in my case:

# aptitude install android-tools-adb android-tools-fastboot

These packages contain “adb” and “fastboot” command required to complete device flashing process.

Once tablet is connected to PC and to have enabled USB debugging option and be enabled Developer Options explained here it executes this command to boot in fastboot mode:

$ adb reboot bootloader
$ fastboot devices
XXXXXXX  fastboot

XXXXXXX -> Device serial number

The next command is used to unlock the bootloader:

$ fastboot oem unlock

After this point to re-enable USB debugging it’s needed to be able to continue. Now it’s time to install  custom recovery image, to know more about recovery images visit this page. It’s needed to download the image to be installed, for me it was:

  • Connect the device to computer via USB (as we did in an earlier step)
  • Execute these commands:
$ adb reboot bootloader
$ fastboot devices
XXXXXXX  fastboot
$ cd Downloads && fastboot flash recovery twrp-
sending 'recovery' (11850 KB)...
OKAY [  1.764s]
writing 'recovery'...
OKAY [  0.397s]
finished. total time: 2.160s
  • Reboot the device into recovery just to check the recovery image is correctly installated.

Now let’s continue with CyanogenMod installation from custom recovery mode, the first step would be to download the build package for your tablet. I decided to use a release version because is the stable package version (
I also downloaded this file from here.

  • Place the build package, zip file, on the root of /sdcard/ using this command:
$ cd ~/Downloads && adb push /sdcard/
$ adb push
  • Boot to recovery mode (Team Win Recovery Project), for my device is needed to hold Volume Up, Volume Down and the Power button, to be able to flash CyanogenMod image.

It’s highly recommended create a backup before flashing the image zip file. After that, select Wipe and then Factory Reset, then select Install option navigate to /sdcard and select file, follow the messages printed on screen. To install Open GApps image follow the same process.

Just you need to reboot Nexus 7 and check if CyanogenMod is running properly.

I want to thank to “The CyanogenMod Team”, its Community and “The Open GApps Team” for their effort, thanks guys!

Some acronyms related with this topic:

  1. OEM: Original Equipment Manufacturer
  2. OTA: Open Tools API
  3. USB: Universal Serial Bus

Reference links:


“I understand that readers do not need to know these things; but I need to tell them”
— Rousseau.

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