[Barnes & Noble Nook Tablet] sigmabeta:
The 16GB Nook Tablet was released in the United States on Nov 17, 2011 (about 6 months ago). It is reasonably well-documented and a great deal of progress has been made on getting it to do cool stuff that its developers did not intend.

On February 21, 2012 (about 2 months ago) Barnes and Noble released an 8GB version of the Nook Tablet. It is much newer and most of the developers on XDA who were going to work with the Nook Tablet had already purchased 16GB devices by the time the 8GB was released; therefore, it is not documented nearly as well and many of its quirks are not as well known.

The purpose of this thread is to begin the process of documenting the differences between the two tablets. I spent a lot of time messing around with unsuccessful processes and asking questions to people who didn't know answers, and would like to contribute by saving that time for others.

By following this guide, you will be able to take an 8GB Nook Tablet out of the box and get it running an alpha version of CM9.

As of 04/25, CM9 for the Nook Tablet is an alpha state and many, many things do not work. I urge you not to try this yet unless you want to contribute to the development process, because you might irreversibly mess up your $200 toy. I am not responsible if you do this. Please, please do not try this unless you know what you are doing!

You will need:

8GB Nook Tablet (duh)

1 MicroSD card that you don't mind wiping

Linux (I only know how to flash images to an SD card using Linux, if someone else wants to add Windows instructions it's appreciated, but honestly if you can't find your way around Linux you shouldn't do this)

ADB properly set up (there are other guides on how to do this, I will add it in later if necessary)

Some way of writing to a MicroSD (an SD reader preferably, you could use an android device but I would feel much safer with just an SD reader)

The recovery image from the bottom of this post (ignore the instructions, just get the image. Meghdoot please let me know if I can just include the direct link in this post.)

CM9 Alpha 0.03 zipped package from this post (filename: update-cm9-acclaim-alpha0.03-fullofbugs.zip)

Google Apps ICS flashable zip (optional, find it somewhere if you want it)

Actually flashing CM9 is not that hard. The problem is that we want to make sure we have a way out of any problems we might cause (maybe you get sick of CM9 for example.) There are slight differences between the 8 and 16GB versions of the NT. These differences make a lot of the recovery methods for the 16GB not work on the 8GB. Do NOT flash anything to your tablet unless you are sure it works for the 8GB model!

Overview: What We Are Going To Do To Your Tablet

Create ClockWork Mod Recovery SD card

Back up your existing stock system

Save rombackup.zip, which contains files that are critical to the Stock OS

Flash CM9

Step 1: Create CWM Recovery SD Card

This step is the most important because it lets us do just about everything else. It is very important that you follow this step precisely and not cut corners; for example, it is tempting to use xIndirect's Nook Tab Recovery Flasher app because it downloads CWM and flashes it to your tablet so you don't have to mess with an SD; the CWM version it flashes will not work on the 8GB tablet, and once you realize this and use the app to "revert to stock recovery", you will find that you have reverted to a 16GB stock recovery. I made this mistake, and so far don't know how to undo it (hopefully I won't have to).

1) Get your SD card readable in your computer

Alternate, perhaps easier method: Copy the contents of this file onto the sd card. Either do this or steps 2-4 below, whichever you prefer.

2) Unmount your SD card, but do not remove it

3) Unzip the CWM image you downloaded above, which should contain myrecovery.img

4)In Linux, do the following:

sudo dd if=myrecovery.img of=WhateverTheMountPointofSDCardIs bs=1M

Don't know how to find what your SD card's mount point is? TURN BACK.

In Windows, do the following:

Once this is done you should be able to place the SD card into your Nook Tablet, power it down, plug the USB cable while it is off, and it will turn on, show the Nook logo, a white screen with a cardboard box, and then load up CWM recovery.

Step 2: Nandroid Backup

This should be the simplest way to have a plan B - if you want to go back to stock ever, this should do it.

1) In ClockworkMod Recovery, press volume down until Backup and Restore is highlighted; press the home key to select it.

2) Choose "Backup to Internal Sdcard"

3) After a few minutes, verify that the backup was successfully completed.

You should have about 3.5GB free on your eMMC before the backup, and the backup will likely take about 800MB. (Please chime in if your backup is bigger / smaller.)

Step 3: Get Rombackup.zip

This file is very important. In the event that your tablet is completely borked, we could try flashing an image of a stock OS to it; however, there is a file in the stock OS called rombackup.zip which identifies your Nook when it tries to connect to BN's services. If you flash someone else's image you will have someone else's rombackup.zip and BN will not let you in.

1) On Ubuntu, with your tablet in CWM Recovery, do

$ adb shell

This will open up a terminal to your tablet, where you must type these commands VERY PRECISELY (!!!!):

mkdir /mnt
mkdir /mnt/factory
mount -t ext4 /dev/block/mmcblk0p7 /mnt/factory
exit

2)After "exit", you will be returned to your Ubuntu terminal; from there do

adb pull /mnt/factory/rombackup.zip

3) Put that file somewhere safe! Dropbox is a good idea.

Step 4: Flash CM9

1) Reboot your tablet into stock OS one last time.

2) Mount your nook's storage to your PC

3) Place the cm9 update zip file you downloaded above onto the nook's storage

4) Reboot into CWM Recovery

5) Choose "Install zip from sdcard"

6) Choose "Choose zip from internal sdcard"

7) Find the CM9 zip, flash it

8) Find gapps (if you got it), flash it

9)

NOT OPTIONAL

Choose "wipe data/factory reset" (if not visible, press power button to go back)

10) Reboot, pray

Your tablet should boot into a shiny new operating system. If you get tired of it, just restore stock using nandroid (takes seconds and works without a problem.) The experience within CM9 is not so different from the 16GB; however you will find since it only has 512MB of ram instead of 1GB, apps have to restart a lot more frequently than you would hope, because they are killed by Android's memory management if you hop to too many other apps. That's the tradeoff for the $50 you saved, cheapskate.

MANY THANKS TO:

The entire CM9 Nook Tablet team (too many to list)

Meghdoot for producing a working 8GB recovery + answering some ?s

fattire, bauwks, etc - for cracking the **** out of the security on these things

Anybody else I left out - this dev community just amazes me

Lastly - this is my first attempt at being useful on XDA, so please let me know if I made any mistakes, or if there is something you think I should add.