Cyanogenmod ROM Google Nexus 7 Wi-Fi (2013 version) (flo)

Quick Info

Check out Google Nexus 7 (Wi-Fi, 2013 version) (“flo”) with newer LineageOS software

Download CyanogenMod

Download (nightly build)
CyanogenMod 14.1 (Android 7.1 (Nougat))

Main sections for Google Nexus 7 (Wi-Fi, 2013 version) (“flo”)

1. Information about Google Nexus 7 (Wi-Fi, 2013 version) (“flo”)
2. CyanogenMod install guide for Google Nexus 7 (Wi-Fi, 2013 version) (“flo”)
3. Build CyanogenMod and CyanogenMod Recovery guide

Special boot modes

• Recovery: With the device powered down, hold the Volume Down and Power buttons until the bootloader appears, then release the buttons. Navigate using the volume keys and select RECOVERY using the Power key.
• Bootloader: With the device powered down, hold the Volume Down and Power buttons until the bootloader appears, then release the buttons.
• Fastboot: With the device powered down, hold the Volume Down and Power buttons until the bootloader appears, then release the buttons. There should be text on the screen indicating you are in fastboot mode.

Source code

Device	http://www.github.com/cyanogenmod/android_device_asus_flo
Kernel	http://www.github.com/cyanogenmod/android_kernel_google_msm

Nexus 7 (Wi-Fi, 2013 version) Specifications

Codename:	flo
Vendor:	Google
Manufacturer:	Asus
Release date:	2013 July 26
Type:	tablet
Platform:	Qualcomm Snapdragon S4 Pro
CPU:	1.5 GHz quad-core Snapdragon S4 Pro Krait 300
GPU:	Adreno 320
RAM:	2GB
Weight:	290 g
Screen size:	178 mm (7.0 in)
Resolution:	1920×1200 pixels
Screen density:	323 ppi
Screen type:	IPS LCD
Internal storage:	16GB, 32GB
Bluetooth:	4.0 LE
Wi-Fi:	802.11 a/b/g/n @ 2.4 GHz & 5 GHz
Main camera:	5MP, flash: none
Secondary camera:	1.2MP
Power:	3950 mAh
CM supported:	10.2, 11, 12, 12.1, 13, 14.1

How to Install CyanogenMod on the Google Nexus 7 (Wi-Fi, 2013 version) (flo)

Unlocking the bootloader

1. Make sure your computer has working fastboot and adb.
2. Enable USB debugging on the device.
3. Enable OEM unlock in the Developer options settings on the device. (Note: Not all devices have this setting, so continue with next step if yours does not.)
4. Connect the device to the computer through USB.
5. From a terminal on a computer, type the following to boot the device into fastboot mode:

   adb reboot bootloader

6. Once the device is in fastboot mode, verify your PC sees the device by typing fastboot devices
   • If you don’t see your device serial number, and instead see “<waiting for device>”, fastboot is not configured properly on your machine. See fastboot documentation for more info.
   • If you see “no permissions fastboot”, try running fastboot as root.
7. From the same terminal, type the following command to unlock the bootloader:

   fastboot oem unlock

8. A disclaimer will display on the device that must be accepted. Use the volume keys to cycle through the options. Pressing the power button should confirm your selection.
9. If the device doesn’t automatically reboot, reboot it from the menu. It should now be unlocked. You can confirm this is the case if you see an unlocked icon at the bottom of the Google boot screen during reboots.
10. Since the device resets completely, you will need to re-enable USB debugging on the device to continue.

Installing a custom recovery using fastboot

See All About Recovery Images for more information about custom recoveries and their capabilities.

1. Make sure your computer has working fastboot and adb.
2. Download recovery — you can directly download a recovery image using the link below, or visit twrp.me to obtain the latest version of Team Win Recovery Project for your device.

   Recovery: Download

   md5: 08dacc40ca1a3c2565667d8679ec84cb

3. Connect the Nexus 7 (Wi-Fi, 2013 version) to the computer via USB.
4. Make sure the fastboot binary is in your PATH or that you place the recovery image in the same directory as fastboot.
5. Open a terminal on your PC and reboot the device into fastboot mode by typing

   adb reboot bootloader

   or by using the hardware key combination for your device while it is powered off.

6. Once the device is in fastboot mode, verify your PC sees the device by typing

   fastboot devices

   • If you don’t see your device serial number, and instead see “<waiting for device>”, fastboot is not configured properly on your machine. See fastboot documentation for more info.
   • If you see “no permissionsfastboot”, make sure your UDEV rules are setup correctly.
7. Flash recovery onto your device by entering the following command:

   fastboot flash recovery your_recovery_image.img

   where the latter part is the filename of the recovery image.

8. Once the flash completes successfully, reboot the device into recovery to verify the installation. Boot to recovery instructions: With the device powered down, hold the Volume Down and Power buttons until the bootloader appears, then release the buttons. Navigate using the volume keys and select RECOVERY using the Power key.
   • Note: Some ROMs overwrite recovery at boot time so if you do not plan to immediately boot into recovery to install CyanogenMod, please be aware that this may overwrite your custom recovery with the stock one.

Installing CyanogenMod from recovery

1. Make sure your computer has working adb.
2. Download the CyanogenMod build package for your device that you’d like to install to your computer.

   Optional: Download 3rd party applications packages, like Google Apps which are necessary to download apps from Google Play.

3. Place the CyanogenMod .zip package, as well as any optional .zip packages, on the root of /sdcard:
   • Using adb: adb push filename.zip /sdcard/

   Note: You can copy the .zip packages to your device using any method you are familiar with. The adb method is used here because it is universal across all devices and works in both Android and recovery mode. If you are in recovery mode, you may need to ensure /sdcard (sometimes called Internal Storage) is mounted by checking its status in the Mounts menu. If you have booted regularly, USB debugging must be enabled.

4. If you are not already in recovery, boot to recovery mode now.
   • With the device powered down, hold the Volume Down and Power buttons until the bootloader appears, then release the buttons. Navigate using the volume keys and select RECOVERY using the Power key.
5. In Team Win Recovery Project, select menu choices by tapping on the appropriately labelled button.
6. Optional (Recommended): Select the Backup button to create a backup.
7. Select Wipe and then Factory Reset.
8. Select Install.
9. Navigate to /sdcard and select the CyanogenMod .zip package.
10. Follow the on-screen notices to install the package.
11. Optional: Install any additional packages you wish using the same method (if you are installing multiple packages, install CyanogenMod first and then install any subsequent packages on top of it).
12. Once installation has finished, return to the main menu and select Reboot, then System. The device will now boot into CyanogenMod.

How To Build CyanogenMod For Google Nexus 7 (Wi-Fi, 2013 version) (flo)

Introduction

These instructions will hopefully assist you to start with a stock Nexus 7 (Wi-Fi, 2013 version), unlock the bootloader (if necessary), and then download the required tools as well as the very latest source code for CyanogenMod (based on Google’s Android operating system). Using these, you can build both CyanogenMod and CyanogenMod Recovery image from source code, and then install them both to your device.

It is difficult to say how much experience is necessary to follow these instructions. While this guide is certainly not for the very very very uninitiated, these steps shouldn’t require a PhD in software development either. Some readers will have no difficulty and breeze through the steps easily. Others may struggle over the most basic operation. Because people’s experiences, backgrounds, and intuitions differ, it may be a good idea to read through just to ascertain whether you feel comfortable or are getting over your head.

Remember, you assume all risk of trying this, but you will reap the rewards! It’s pretty satisfying to boot into a fresh operating system you baked at home :) And once you’re an Android-building ninja, there will be no more need to wait for “nightly” builds from anyone. You will have at your fingertips the skills to build a full operating system from code to a running device, whenever you want. Where you go from there– maybe you’ll add a feature, fix a bug, add a translation, or use what you’ve learned to build a new app or port to a new device– or maybe you’ll never build again– it’s all really up to you.

What you’ll need

• A Nexus 7 (Wi-Fi, 2013 version)
• A relatively recent computer (Linux, OS X, or Windows) with a reasonable amount of RAM and about 100 GB of free storage (more if you enable ccache or build for multiple devices). The less RAM you have, the longer the build will take (aim for 8 GB or more). Using SSDs results in considerably faster build times than traditional hard drives.
• A USB cable compatible with the Nexus 7 (Wi-Fi, 2013 version) (typically micro USB, but older devices may use mini USB or have a proprietary cable)
• A decent internet connection & reliable electricity :)
• Some familiarity with basic Android operation and terminology. It would help if you’ve installed custom roms on other devices and are familiar with recovery. It may also be useful to know some basic command line concepts such as cd for “change directory”, the concept of directory hierarchies, that in Linux they are separated by /, etc.

If you are not accustomed to using Linux– this is an excellent chance to learn. It’s free– just download and run a virtual machine (VM) such as Virtualbox, then install a Linux distribution such as Ubuntu (AOSP vets Ubuntu as well). Any recent 64-bit version should work great, but the latest is recommended.

Using a VM allows Linux to run as a guest inside your host computer– a computer in a computer, if you will. If you hate Linux for whatever reason, you can always just uninstall and delete the whole thing. (There are plenty of places to find instructions for setting up Virtualbox with Ubuntu, so I’ll leave it to you to do that.)

So let’s begin!

Unlocking your Nexus 7 (Wi-Fi, 2013 version)

What does “unlocking” mean?

The first step in putting any custom operating system on your Nexus 7 (Wi-Fi, 2013 version) is to unlock the bootloader. A bootloader is the very first program that runs when you turn on your device. The bootloader initializes some hardware and then loads the kernel and ramdisk, and gets the boot process going. If the bootloader is in locked mode, it will ensure that only the stock operating system can run. Since you will be installing your own operating system, you need to turn this off. Luckily, Google and asus make it easy.

Okay. I’m in. What do I need to do this?

To unlock your bootloader, you’ll first need a program on your computer called fastboot. One way to get fastboot is to download and install the Android SDK (Software Developer Kit) from Google. The SDK is used by app developers when they’re writing programs for Android, and who knows, you may want to write apps someday. But the SDK also contains two great tools that are useful even to non-developers. They are:

• adb – Android Debug Bridge – this is a program that lets your computer “talk” to your Nexus 7 (Wi-Fi, 2013 version) while the device is running. Among the many things you can do with adb– you can push files from your computer to the device or pull files from the device to your computer, you can get a running real-time log of Android activity (which is very useful for debugging or having others help you debug), you can create an interactive “shell” session (similar to Linux or OS X) to type commands to your device, and much more.

• fastboot – fastboot works a little bit like adb, except it’s often used at a much earlier point in the boot process, even before Android or any operating system loads. You can put your Nexus 7 (Wi-Fi, 2013 version) into a “fastboot” mode, whereby, if you are connected via USB cable, you can copy entire partitions from your computer (usually in the form of an image file, such as boot.img or recovery.img) over to the device, wiping over whatever happened to be there. Fastboot is able to do more than that, however. It’s also used to send special commands to the device to do things such as unlock your bootloader.

How do I do the actual unlocking?

So this should be a one time thing…

Install the Android SDK

To unlock your Nexus 7 (Wi-Fi, 2013 version), you will need fastboot installed. Go ahead and download the SDK, per the steps on Google’s web page. Then install it by following the specific instructions for your computer.

Unlocking the bootloader

1. Make sure your computer has working fastboot and adb.
2. Enable USB debugging on the device.
3. Enable OEM unlock in the Developer options settings on the device. (Note: Not all devices have this setting, so continue with next step if yours does not.)
4. Connect the device to the computer through USB.
5. From a terminal on a computer, type the following to boot the device into fastboot mode:

   adb reboot bootloader

6. Once the device is in fastboot mode, verify your PC sees the device by typing fastboot devices
   • If you don’t see your device serial number, and instead see “<waiting for device>”, fastboot is not configured properly on your machine. See fastboot documentation for more info.
   • If you see “no permissions fastboot”, try running fastboot as root.
7. From the same terminal, type the following command to unlock the bootloader:

   fastboot oem unlock

8. A disclaimer will display on the device that must be accepted. Use the volume keys to cycle through the options. Pressing the power button should confirm your selection.unlock the bootloader:

9. If the device doesn’t automatically reboot, reboot it from the menu. It should now be unlocked. You can confirm this is the case if you see an unlocked icon at the bottom of the Google boot screen during reboots.
10. Since the device resets completely, you will need to re-enable USB debugging on the device to continue.

Troubleshooting

If you have issues with fastboot or adb not being found, make sure that the Android SDK folder /platform-tools, which contains the adb and fastboot files, are in the path of execution for commands typed at the terminal. Usually typing something like

# PATH=$PATH:/your/specific/path/to/android/sdk/platform-tools/

will work for that terminal session.

$ sudo apt-get install ia32-libs

You’ll be using fastboot again to install a custom recovery.

Build CyanogenMod and CyanogenMod Recovery

Prepare the Build Environment

Install the SDK

If you have not previously installed adb and fastboot, install the Android SDK. “SDK” stands for Software Developer Kit, and it includes useful tools that you can use to flash software, look at the system logs in real time, grab screenshots, and more– all from your computer.

Install the Build Packages

Several “build packages” are needed to build CyanogenMod. You can install these using the package manager of your choice.

For both 32-bit & 64-bit systems, you’ll need:

bc bison build-essential curl flex git gnupg gperf libesd0-dev liblz4-tool libncurses5-dev libsdl1.2-dev libwxgtk2.8-dev libxml2 libxml2-utils lzop maven openjdk-7-jdk pngcrush schedtool squashfs-tools xsltproc zip zlib1g-dev

In addition to the above, for 64-bit systems, get these:

g++-multilib gcc-multilib lib32ncurses5-dev lib32readline-gplv2-dev lib32z1-dev

For Ubuntu 15.10 (wily) and newer, substitute:

• lib32readline-gplv2-dev → lib32readline6-dev

For Ubuntu 16.04 (xenial) and newer, substitute (additionally see java notes below):

• libwxgtk2.8-dev → libwxgtk3.0-dev
• openjdk-7-jdk → openjdk-8-jdk

Java versions: Different versions of CyanogenMod require different versions of the JDK (Java Development Kit):

• CyanogenMod 7 – 9: Sun/Oracle Java SE 1.6
• CyanogenMod 10.1: Sun/Oracle Java SE 1.6 or 1.7
• CyanogenMod 10.2 – 11.0: Sun/Oracle Java SE 1.6 or 1.7 (OpenJDK 1.7 works fine, but the build system will display a warning)
• CyanogenMod 12.0 – 13.0: OpenJDK 1.7 (see note about OpenJDK 1.8 below)
• CyanogenMod 14.1: OpenJDK 1.8

Ubuntu 16.04 (Xenial Xerus) or newer and OpenJDK: Since OpenJDK 1.7 was removed from the official Ubuntu repositories, you have a couple options:

1. Obtain OpenJDK 1.7 from the openjdk-r PPA
2. Enable experimental OpenJDK 1.8 support in CyanogenMod 13.0 (not available in earlier version). To enable OpenJDK 1.8 support, add this line to your $HOME/.bashrc file: export EXPERIMENTAL_USE_JAVA8=true.

Also see http://source.android.com/source/initializing.html which lists needed packages.

Create the directories

You will need to set up some directories in your build environment.

To create them:

$ mkdir -p ~/bin
$ mkdir -p ~/android/system

Install the repo command

Enter the following to download the “repo” binary and make it executable (runnable):

$ curl https://storage.googleapis.com/git-repo-downloads/repo > ~/bin/repo
$ chmod a+x ~/bin/repo

Put the ~/bin directory in your path of execution

In recent versions of Ubuntu, ~/bin should already be in your PATH. You can check this by opening ~/.profile with a text editor and verifying the following code exists (add it if it is missing):

# set PATH so it includes user's private bin if it exists
if [ -d "$HOME/bin" ] ; then
    PATH="$HOME/bin:$PATH"
fi

Initialize the CyanogenMod source repository

Enter the following to initialize the repository:

Note: Make sure the cm branch entered here is the one you wish to build and is supported on your device.

$ cd ~/android/system/
$ repo init -u https://github.com/CyanogenMod/android.git -b cm-13.0

Download the source code

To start the download of all the source code to your computer:

$ repo sync

The CM manifests include a sensible default configuration for repo, which we strongly suggest you use (i.e. don’t add any options to sync). For reference, our default values are -j 4 and -c. The -j 4 part means that there will be four simultaneous threads/connections. If you experience problems syncing, you can lower this to -j 3 or -j 2. -c will ask repo to pull in only the current branch, instead of the entire CM history.

Prepare to wait a long time while the source code downloads.

Get prebuilt apps (CM11 and below)

Next,

$ cd ~/android/system/vendor/cm

then enter:

$ ./get-prebuilts

You won’t see any confirmation- just another prompt. But this should cause some prebuilt apps to be loaded and installed into the source code. Once completed, this does not need to be done again.

Prepare the device-specific code

After the source downloads, ensure you are in the root of the source code (cd ~/android/system), then type:

$ source build/envsetup.sh
$ breakfast flo

This will download the device specific configuration and kernel source for your device. An alternative to using the breakfast command is to build your own local manifest. To do this, you will need to locate your device on CyanogenMod’s GitHub and list all of the repositories defined in cm.dependencies in your local manifest.

Extract proprietary blobs

Now ensure that your Nexus 7 (Wi-Fi, 2013 version) is connected to your computer via the USB cable and that you are in the ~/android/system/device/asus/flo directory (you can cd ~/android/system/device/asus/flo if necessary). Then run the extract-files.sh script:

$ ./extract-files.sh

You should see the proprietary files (aka “blobs”) get pulled from the device and moved to the ~/android/system/vendor/asus directory. If you see errors about adb being unable to pull the files, adb may not be in the path of execution. If this is the case, see the adb page for suggestions for dealing with “command not found” errors.

Turn on caching to speed up build

You can speed up subsequent builds by adding

export USE_CCACHE=1

to your ~/.bashrc file (what’s a .bashrc file?). Then, specify the amount of disk space to dedicate to ccache by typing this from the top of your Android tree:

prebuilts/misc/linux-x86/ccache/ccache -M 50G

where 50G corresponds to 50GB of cache. This only needs to be run once and the setting will be remembered. Anywhere in the range of 25GB to 100GB will result in very noticeably increased build speeds (for instance, a typical 1hr build time can be reduced to 20min). If you’re only building for one device, 25GB-50GB is fine. If you plan to build for several devices that do not share the same kernel source, aim for 75GB-100GB. This space will be permanently occupied on your drive, so take this into consideration. See more information about ccache on Google’s android build environment initialization page.

Start the build

Time to start building! So now type:

$ croot
$ brunch flo

The build should begin.

If the build breaks…

• If you experience this not-enough-memory-related error…

ERROR: signapk.jar failed: return code 1make: *** [out/target/product/flo/cm_flo-ota-eng.root.zip] Error 1

…you may want to make the following change to ~/android/system/build/tools/releasetools/common.py:

Search for instances of -Xmx2048m (it should appear either under OPTIONS.java_args or near usage of signapk.jar), and replace it with -Xmx1024m or -Xmx512m.

Then start the build again (with brunch).

• If you see a message about things suddenly being “killed” for no reason, your (virtual) machine may have run out of memory or storage space. Assign it more resources and try again.

Install the build

Assuming the build completed without error (it will be obvious when it finishes), type:

$ cd $OUT

in the same terminal window that you did the build. Here you’ll find all the files that were created. The stuff that will go in /system is in a folder called system. The stuff that will become your ramdisk is in a folder called root. And your kernel is called… kernel.

But that’s all just background info. The two files we are interested in are (1) recovery.img, which contains CyanogenMod Recovery, and (2) cm-13.0-20161224-UNOFFICIAL-flo.zip, which is the CyanogenMod installation package.

Installing a custom recovery using fastboot

See All About Recovery Images for more information about custom recoveries and their capabilities.

1. Make sure your computer has working fastboot and adb.

1. Connect the Nexus 7 (Wi-Fi, 2013 version) to the computer via USB.
2. Make sure the fastboot binary is in your PATH or that you place the recovery image in the same directory as fastboot.
3. Open a terminal on your PC and reboot the device into fastboot mode by typing

   adb reboot bootloader

   or by using the hardware key combination for your device while it is powered off.

4. Once the device is in fastboot mode, verify your PC sees the device by typing

   fastboot devices

   • If you don’t see your device serial number, and instead see “<waiting for device>”, fastboot is not configured properly on your machine. See fastboot documentation for more info.
   • If you see “no permissionsfastboot”, make sure your UDEV rules are setup correctly.
5. Flash recovery onto your device by entering the following command:

   fastboot flash recovery your_recovery_image.img

   where the latter part is the filename of the recovery image.

6. Once the flash completes successfully, reboot the device into recovery to verify the installation.
   • Note: Some ROMs overwrite recovery at boot time so if you do not plan to immediately boot into recovery to install CyanogenMod, please be aware that this may overwrite your custom recovery with the stock one.

Install CyanogenMod

Back to the $OUT directory on your computer– you should see a file that looks something like:

cm-13.0-20161224-UNOFFICIAL-flo.zip

Now you can flash the cm...zip file above as usual via recovery mode. Before doing so, now is a good time to make a backup of whatever installation is currently running on the device in case something goes wrong with the flash attempt. While CyanogenMod Recovery doesn’t have a backup feature, there are other custom recoveries available that do. You can also use something like Titanium Backup (root required) as an alternative.

Success! So….what’s next?

You’ve done it! Welcome to the elite club of self-builders. You’ve built your operating system from scratch, from the ground up. You are the master/mistress of your domain… and hopefully you’ve learned a bit on the way and had some fun too.

Now that you’ve succeeded in building CyanogenMod for your device, here are some suggestions on what to do next.

Also, be sure to take a glance at the Dev Center on this wiki for all kinds of more detailed information about developer topics ranging from collecting logs, understanding what’s in the source code directories, submitting your own contributions, porting CyanogenMod to new devices, and a lot more.

Congrats again!

Content of this page is based on informations from wiki.cyanogenmod.org, under CC BY-SA 3.0 licence.