Originally had Nexus 7 Wi-Fi 16 Gb stock 4.2.2 rooted. (It was also CWM, but due to the peculiarities MultiBOOT replaced it with TWRP, the initial presence / absence of custom recovery is unimportant to follow the instructions)
Steps to follow:
1. Download and installGomanager.
2. From GooManager downloaded and installed TWRP Recovery.
3. Download and install[XDA] Flash Image GUI app.
4. Download modified recoveryTWRP for multiboot
5. From the Flash Image GUI I downloaded the downloaded TWRP for multiboot.
6. DownloadMultiROM v10 n7 signed.
7. With the help of GooManager, I rebooted into TWRP, flashed the MultiROM, rebooted into the system.
8. I downloaded the modified kernel for android -kernel 4.2.2and the veryUbuntu 13.04.
9. Rebooted to TWRP, I requested the kernel.
10. Moved to TWRP in Advanced ->MultiROM ->Add ROM. I chose Ubuntu Desktop and set the path to raring-preinstalled-desktop-armhf + nexus7.img.gz
11. 20 minutes of waiting, a message about the successful installation of ROM, rebooted the tablet. I got into the MultiBOOT menu, chose raring-preinstalled-desktop-armhf + nexus7, and got the installer ubunt. Then everything is obvious.
Materials that came to this sequence of actions:
[mod] [16 APR] MultiROM v10 (updated to TWRP 2.5)
[APP] Flash Image GUI - Flash Kernels and Recoveries from normal Android mode!
Original post -Google Nexus 7 Wi-Fi - Ubuntu Firmware (Post # 21442806)
All thanks there

Original on the Ubuntu wiki

First, download the Ubuntu Nexus 7 Desktop Installer

Now we will deal with the device. You will need the fastboot utility included in the Android SDK. SDK installation instructions can be found here:[GUIDE] Backup and restore partitions, firmware recovery, ADB under Linux

Let's enter the device in fastboot mode. Hold the buttons offturning onandvolume downat the same time.
Check if the computer sees the device.

Open the bootloader

Look at the screen and select "YES", but remember - your data will be deleted, therefore save them all (most important in your memory I think, yes?)
Reboot bootloader

Now run the Ubuntu Nexus 7 Installer that you installed at the very beginning and follow the instructions.

Download kernel and system images for your model.from here(rootfs.img and boot.img)
Configure the fastboot utility in my guide:[GUIDE] Backup and restore partitions, firmware recovery, ADB under Linux
For windows: downloaddrivers, Java and Android SDK (links in the guide).
For Linux: just do everything according to the guide.

Now we will enter the device in fastboot mode. Hold the buttons offturning onandvolume downat the same time.
Check if the computer sees the device.

Open the bootloader

Look at the screen and select "YES", but remember - your data will be deleted, therefore save them all (most important in your memory I think, yes?)
Reboot bootloader

Clean out all unnecessary:

Let's flash the kernel and system image

Download MultiROM and Modified Recoveryfrom here, just download the rootfs.img imagefrom here.
Configure the fastboot utility in my guide:[GUIDE] Backup and restore partitions, firmware recovery, ADB under Linux
For windows: downloaddrivers, Java and Android SDK (links in the guide).
For Linux: just do everything according to the guide.

We will modify the modified recovery

and download the downloaded zip through it.
Let's go to the recovery section MultiROM ->Add ROM, choose that we want to install Ubuntu and specify it rootfs.img

Despite the fact that Unity supports quite a lot of guest rooms, only the main ones work (and sometimes they work quite well in GNOME). Their list, who are interested,here
Working guest rooms:
Tap with one finger:Select item
Move one finger:Move item
Double tap:Choose a whole word or item
Triple Tap:Select a paragraph or related items.
Tap with three fingers:Resize window
Tap with four fingers:Open Dash

Hold the power button for 20 seconds

ubuntu

Currently, the -update and -security packages are not allowed for the device (it uses its PPA), as this can break the system or make it unusable.
The reason - patches on packages made specifically for Nexus 7.
Accordingly, it is better not to allow these packages.

It happens that the keyboard does not appear when a window with a text field is selected. It can be turned on manually by clicking on the button.in the panel at the top and selecting Show Onboard.
Also in the settings, you can allow the floating icon.Onboard Preferences >Generalput a tick onShow floating icon when Onboard is hidden

Unfortunately, right click can only be done with Onboard.

Open the system settings (System Settings), take the tabUniversal acessand select on the tabSeeingparameterText sizeonLarger

OpenSystem Settings ->vkaldkaAppearances ->tabLookand move the sliderLauncher Icon Size(maximum 64).

Ubuntu supports OTG-connected peripheral devices. Using a USB hub, you can connect a wired keyboard and mouse at the same time. You can also connect wireless devices with a USB-radio module. An alternative method is Bluetooth (BT-keyboards and mice are more expensive than their wireless counterparts).
For BT-devices have their own characteristics. To connect them will have to take a couple of steps.

Introduce the mouse / keyboard into pairing mode and execute

We get something like

The first is BT-MAC, the second is the name. Connect via BT-MAC

! x!When USB devices are connected via OTG cable, charging is not possible. A docking station that should be out soon will solve this problem.
I use a powered USB hub and plug in a silicone keyboard, laptop mouse. Even without power, it works quietly, but there is more energy. Often I go somewhere else, people in cafes are shocked by me.

You can manage your desktop by VNC. To do this, you can simply find it in Dash (Unity) or in the Internet menu (GNOME)Desktop sharingand set the desired settings. Connect through any VNC client. To find out the IP of the tablet, run on it in the terminal

On Ubuntu, I advise you not to use a standard VNC client, better put Remmina.

Because of the broken BT-stack, the bluetoothd daemon crashing is responsible for managing devices.
The fix has not yet been found, but you can fix the stack through the debgging utility Valgrind.

Now edit the file /etc/init/bluetooth.conf

Replace string

on

and restart BT

If it hangs, reboot.

By default, for some reason, the package is not installedbash-completionwhich makes me shocked by Canonical. This means that we will have on the Tab key only the first word from the chain of commands, or just what we have in the folder. It does not suit me, so it is very boring to put packages through apt-get.

I don’t have to think long - from the most accessible in the repositories and really lightweight I singled out the GNOME Classic.

After installation, perform Log Out and in the login menu next to the username in the frame you will see the clickable icon of the Unity logo. Click it and select GNOME Classic (No Effects)

Having tested the read / write speed of the flash drive in the Nexus 7, I realized that it should be very beneficial to use, since the swap on an external device is a perversion.
First, create an empty file of the desired size via dd in a convenient place, namely / swap /

bs = 1M1000 x 1000 blocks
count = 500500 x 1M ~ 500MB
That is, we have created an empty 500MB file that will become our swap.

Check the performance by connecting it

Listed on the list? So it should be written in/ etc / fstabfor autostart on buta.

Pin down

Now we will set the parameters for using swap

We attach at the end of the file

swappiness = 50 means that at 100-50 = 50% of the occupied RAM, we will start using swap.
vfs_cache_pressure = 10 means that under the cache we will select this value. Usually, changing this parameter does not give a special win, except in reading / writing. By default, it is 1000 in Ubuntu, but with my tests I derived the most appropriate value for our weak pseudo netbook.
You can play around with the swappiness parameter, but it seems to me that I set quite a reasonable value. Well, maybe 40-45 more values ​​should be nothing.

preload allows you to run programs faster by storing some information about the libraries in RAM. This amount is very small and is calculated from the total volume, so put it boldly.

Slightly improve performance by utilizing the power of the zram processor. It will unload small parts of what lies in tmpfs to speed up the RAM, since the compressed data in it has a fast read and write speed.
A virtual swap will be created for each processor thread and will be denoted by / dev / zramX

After that, you will be surprised at the incorrect display of the paging in the System Monitor. Want an explanation?

Here they are.

Redraw the Onboard for the GNOME Classic.
Turn it off first

Now draw

We will press the combiningctrl + c.
Now you can run it as a regular application through the GUI and enjoy saving the settings when the system restarts.
If you want the keyboard to not hide the panel below, but use the parameter-y 505

I do not think that you will print from the tablet. If you want to - use Google Cloud Print, do not bother with a USB connection. Because we will remove CUPS! Well, avahi ...