[Nook Color General] bachon:
Nook Rooting 101

Author’s Note: This may be long, but it provides useful info to those considering Rooting their Nook. It does NOT tell you how to root your Nook. (A sequel is intended to provide that information. But let’s start with this one.)

To the experts: feel free to post with your corrections and condemnations. The hope is that it will be improved and eventually turned into a Sticky for those new to the forum and the process.

“I got a new Nook for my birthday. What’s all this stuff about rooting?”

The Barnes & Noble Nook eReaders share some of the same electronic architecture as many smart phones and tablets. These devices work using the Android Operating system. The factory installed OS (Operating System) of the Nook limits many of the possible advanced features since it was designed primarily to be a reader. Some tech-savvy programmers have learned how to root the Nook devices to more closely emulate advanced features found on many of the Android devices.

Quick detour: Those wanting to root their Nooks are going to run into a lot of terminology. Here is a link to a glossary of many of these terms.

http://www.acertabletforum.com/foru...-dummies-guide-android-terminology-lingo.html

The number of terms addressed within this post will be a much smaller number. But these are terms that you really should understand before attempting to make changes in your Nook.

What is Rooting?

The term “root” comes from the Unix/Linux world and is used to describe a user who has “Superuser” rights or permissions to all the files and programs in the software OS. Regular users can use the software, but cannot make changes. Superuser privileges allow changes to the software code on the device.

“Rooting” means obtaining “superuser” rights to your Nook’s software. You gain the ability to load custom ROMs, install custom themes, increase performance, increase battery life, and the ability to install software that would otherwise cost extra. Rooting is essentially “hacking” your Nook.

ROMs

A stock ROM is the version of the device’s operating system that comes loaded on it when you buy it. The Nook Readers have a stock ROM.

A custom ROM is a fully standalone version of the OS, including the kernel (which makes everything run), apps, services, etc - everything you need to operate the device, except it's customized by someone in some way..

So what does the "customized" part mean? Since Android is open source, developers are free to take stock ROMs, modify them, remove garbage, optimize them, add things, and pretty much do whatever their imagination and skills allow. (And just so you know, they can also write bad programming too.)

Kernals

Another word you’ll frequently see on this site is kernel. Your Nook’s kernel controls much of the communication between the various electronic parts of the unit. An analogy is that the kernel is like programming stored in the Read Only Memory found on desktop and laptop computers. Think of the BIOS (Binary Input Output System). Some portions of the settings in this memory can be changed, such as when you install a hard disk drive. BIOS also allow other settings to be adjusted to suit the preferences of various users. But other portions of the BIOS should not be changed or your computer’s electronics cannot communicate with one another.

That is a pretty close approximation to how the kernel on your Nook is setup. Some portions of the programming were set at the factory and should not be changed. But other portions of the programming can be changed. And updates to the programming for kernels are made available.

Many of the custom ROMS you can load on your Nook will make at least some changes within the kernel of your unit. Just as there are various versions of the custom ROMs. There are versions of the programming for kernels as well. Let’s stop there for now. The subject can quickly get pretty deep. That should be enough for now.

Two Approaches

Some people who want to use one of these custom ROM systems on their Nook just install the MOD on a SD chip. (SD stands for Secure Digital.) All current Nook readers accept a Micro SD chip. A custom ROM can be loaded onto your Nook from this SD chip. Some people choose to Root their Nook with the Android Operating System operating from the SD chip. Then by powering down the Nook, they can remove the SD card. They can then restart their Nook and the regular Barnes & Noble system will operate.

At least some of the custom ROMs allow users to select whether to run the operating system (ROM) installed on the SD card, or run the native Nook operating system. You don’t need to go through the process of inserting or removing the SD card to change the OS. A series of keys are pressed as the Nook is starting to select the ROM you want it to run. This is called dual booting.

The other method of rooting consists of loading the custom ROM into the emmc. (This stands for Embedded Multi- Media Card.) This is the flash memory of your Nook that contains the original Barnes & Noble operating system. Loading the ROM into the emmc means the original B & N operating system is no longer available to run. Many advanced users report the ROMs operate a bit faster and that there are fewer problems when the Nook is run in this manner. But do remember that this means the original operating system on your Nook will no longer run. There are instructions located on this site that include steps to re-install the original system. So, this may not be as drastic a step as it might seem at first glance. There are also programs which will allow you to save all the data settings – including the OS settings currently loaded on your Nook so they can be restored later. That will not be covered in this post.

Those totally new and unfamiliar with Rooting may find it a little safer to use the SD chip method. As they gain more experience and know better what they are doing they may decide to venture out and try the emmc method for the potential advantages this method offers.

The Downside Of Custom ROMs

Of course, there are dangers of using custom ROMs which you should be aware of.

You May Void Your Warranty

As long as we’re talking about risks, this one needs to be mentioned. It's possible that custom rooting might void your warranty. The manufacturer might be able to tell that the Nook has had a custom ROM installed and not honor the warranty, in case you need to use it. Barnes & Noble hasn’t acted hostile to rooting yet, but that could change.

Something Could Go Wrong

First of all, something may go wrong with the flashing process (that's the process of installing a custom ROM) and leave your Nook in a bricked state. A Bricked Nook means it won’t operate. The chances of this are relatively low – especially if you use the SD chip method. And most of the time you can restore your Nook back to normal. Please take note of the phrase “most of the time”. You should understand that a bricked Nook is a possibility that can happen.

Try to go for a custom ROM that has been tested by time and has lots of positive feedback from users on this site. You are more likely to be successful with such a ROM.

Other Potential Problems

Custom ROMs could have bugs. Bugs are mistakes in the programming. Some are minor and won’t cause big problems. But others can be more serious.

There are appropriate locations on this site where you can post problems due to bugs. Those who post in the ROM forum will likely get an answer back and the bug will probably be acknowledged. Experienced users may even suggest methods to fix the problem.

So What‘s the Bottom Line?

Many of the people at this site have determined that the potential benefits of running these custom ROMs outweigh the risks. There are lots of experienced people here who will offer their advice if you decide to try this. But it is ultimately your responsibility to consider the risks and benefits in deciding what to do.

Quick detour: Let’s be realistic. Your Nook is never going to be an I-Phone. It was designed to be an eReader. (So was the Kindle.) Rooting can add features and capabilities to your Nook that Barnes & Noble probably won’t ever include in their stock ROMs. But rooting won’t really turn your Nook into a smart phone.

“But there are so many choices!”

Yes there are. Let’s try to understand why this is a good thing. Apple and Microsoft own the rights and hold patents on their operating systems. They jealously guard their secrets and strictly enforce their patents. And they make money selling their operating systems.

Unix is also a patented operating system. Linux is an open source operating system based on Unix. It isn’t really owned by anyone. The concept allows many users to tinker with it to improve it. The Android operating system is loosely based on Linux and is also open-source. Developers take stock ROMs and modify them to create their own unique versions. Developers of custom ROMs are able ptimize the software, unlock built-in features, and create an even better version of the Android software. The Android developers who make these custom ROMs release the software to the general public free of charge. We are fortunate to have these developers constantly working and freely sharing these custom ROMs available to everyone.

Stable versus Cool

Since ROMs are constantly being developed by many people, there are multiple flavors of ROMs available to us. Anyone who has ever done any programming knows that sometimes your new code fixes one problem but creates others. Programmers generally call these bugs.

A major portion of the ROMs may work OK, but there may be bugs in portions of the code. Groups of developers collaborate and post their versions of a MOD to be checked out and tested by other users to discover and fix all the bugs.

Then there are some general flavors of the Android system that have become established and are recognized by many. Let’s consider a few of those since you will see these mentioned frequently on this site.

Since April 2009, each Android version has been developed using a codename based on a dessert item. Released in alphabetical order, the names were Cupcake, Donut, Éclair, Froyo, Gingerbread, Honeycomb and Ice Cream Sandwich.

The Android versions distributed within the lifetime of the Nook include:

o	Android 2.1 (codename Eclair)

o	Android 2.2 (codename Froyo)

o	Android 2.3 (codename Gingerbread)

o	Android 3.0 (codename Honeycomb)

Quick detour: One further issue confusing to nubes is that at least some people will refer to a MOD by its Android number, example: 2.3. Others will use a number related to its codename, example CM7.0. Remember these people are really into this stuff. These numbers and differences really stick in their heads. Rule of thumb, if the number is below 4, it’s probably the Android number.

Let’s look at these individually. We’ll use the codenames in this list.

Eclair

Eclair is what your Barnes & Noble Nook Color runs as delivered. And even they are replacing it with Froyo.

Froyo

Many consider Froyo an improvement over Éclair. It has been in use for some time and is considered a stable platform for the Nook. Barnes & Noble is currently (as of 2/5/2012) loading this system using a method called push to update Nooks to run a stripped down version of Froyo. It is important to understand that the B & N version does not have all the features of some of the custom Froyo ROMs.

Gingerbread

The Gingerbread version that many people use has become known as CyanogenMod 7. That’s right – sometimes the system is called Gingerbread and sometimes it is called CyanogenMod 7, though many just refer to it as CM7. It was developed from the official Android Gingerbread source code, but was modified for many smart phones. There are many versions of this that will run on Nooks of various kinds. As of this writing, many consider this a good choice for a Nook operating system. It blends many recent features with at least some degree of stability. The CM 7 releases includes Bluetooth support for the Nook, meaning that you can use Bluetooth keyboards and headsets! It should be noted that Bluetooth support is still evolving.

Honeycomb

This Android system first showed up on the Motorola Xoom tablet. It offers some new features, but has not been released by the official development community. Because such development is constantly underway, some may post test versions for downloading. Be careful! This ROM is still very much in the developmental process. As an example, a few developers have been trying to take features of Honeycomb and include them in updated versions of Gingerbread. One of these versions has been given its own name: phiremod nook.

Generally, Éclair and Froyo, are considered to be stable and mostly bug free. Some versions of Gingerbread are close to being bug free, while other Gingerbread versions are still being sliced, diced, tweaked and tested. Honeycomb is still being tested. If this post stays on this site for a few months, there may be newer and more stable versions of Gingerbread. Or a stable version of Honeycomb for the Nook may become available. And some are experimenting with newer Android systems, like one called IceCreamSandwich. (Remember that this is being written in February of 2012.)

FYI: there are even new flavors of these general ROMS. There is also CM7.1 and CM7.2. And there is a version out there called CM9. So the development community is hard at work tinkering and tweaking.

Finally, as you start to explore and consider MODs for your Nook, you will often see some of these letters in the names of custom MODs.

Stable versions are those where all known issues have been addressed and resolved. This version is for everyday use.

-test / -RC versions are similar to the experimental versions, but are in the final stages of testing before being declared as "stable". There may be a few bugs left, but this version is usually stable enough for everyday use.

Experimental / -alpha versions are those where new features are being added, modified, and tweaked, and there are known bugs that are being worked on. This version is for beta / alpha testers.

Nightly builds are daily compiled builds from source. This version therefore has the latest features & tweaks, but it is also the mostly likely to have bugs and issues. These versions are probably poor choices for nubes.

So which do you want to use? Éclair came on your Nook. And currently, Barnes and Noble is pushing their stock version of Froyo out over the Internet automatically to your Nook. Gingerbread – going by the name of CyanogenMod7.0 – may be a good choice for starting out, as of the date of this writing. Yes, you can upgrade this to later versions as you become familiar with what is out there and how to root your Nook.

End of the lesson.

Hope this information was helpful. Happy Rooting!