Under the hood, an Android phone runs a modified LINUX operating system. Out of the box we, the end users, are given only certain permissions to perform certain actions on this system. We are locked out of other functions, largely for our own good, it is said. Manufacturers don't want us accidentally wiping our OS or allowing apps to do malicious damage.
Anyone who wants to get full control over their computer (I mean, phone) needs root access. This Gizmodo article lists specific reasons why "rooting" is a useful thing. My main reasons are to get full backup capabilities, prior to installing a new Android ROM.
One of the reasons I purchased a Jaiyu G2 is that it was in fact possible to find rooting information. This is not true of all Chinese phones. But the problem is that this information is fragmentary, confusing, and ill-written. Besides which, there are several different methods, requiring different levels of expertise and risk.
The best guide I found, by user "umit" on DroidChina, still lacks clarity for those of us new to this venture. So here I present a rewrite of that guide, all props to the original author.
The following process successfully worked for my Jiayu G2 MT6577 dual core 1GB RAM mobile, and will apparently work for other variants, or even the newer G3 model. This method requires Windows 7 or a similar Microsoft operating system. Of course it goes without saying that this might void your warranty, taint your food, or make you more popular around the water-cooler. Use at your own risk!
There are three main steps.
STEP A: Install development drivers
1. On your Windows box, download and install development USB drivers from the official Android site. This is done by way of the huge SDK kit. Extract this archive to wherever you like on your hard drive. (This might take a while.)
2. In the resulting installation folder, find the sub-folder "/sdk/tools". Run the file "android.bat" to execute the Android SDK Manager. Uncheck all items in the panel. Then select "Extras > Google USB driver". Finally, click "Install".
STEP B: Connect your phone
1. In your Android Settings app, check "Personal > Security > Enable Unknown sources".
2. Also in Settings, check "System > Developer options > USB debugging".
3. Connect your phone to your computer using the USB cable. Swipe down to check notifications. Be sure you are "Connected as a media device". If not, you can tap the USB notification and change the settings. Your notifications should look like those in the following photo.
4. Back in Windows, open "Control Panel > Device Manager". If all is well, there should be an entry for "Android USB Devices > My HTC". (Ha! This phone is a clone of an HTC model.) Looks like this:
STEP C: Root your phone
1. Download the root package. The site is in Chinese but ignore that. Simply click the button with the download symbol. It's the white button immediately to the right of the only blue button.
2. This will give you an archive file named "JYG3??ROOT??.7z", where the question marks are Chinese symbols. Extract this to a temporary folder.
3. In this folder, find the batch file "RunMe.bat". Be sure your phone is awake. Then run the file. At the prompt, choose "Device type > normal" by tapping "1" and then "Enter". Wait a moment until you are prompted to do the next step.
4. Your phone will present the "Full restore" screen as pictured at the top of this article. Do not enter a password. Simply tap "Restore my data". Wait a moment and the phone will reboot, twice. The message "Android Upgrading" will appear for a bit.
5. The phone will then come back to life, same as always. If you check under your application list, you will have a new app, SuperSU. Any programme that requires root access will request it through this application. When this happens, you will be given a prompt in order to confirm access.
That is all. If any of this did not work, do a Google search and dive into the confusing world of Android hacking. The first time I tried, the process failed, but that was only because my phone went asleep between steps 3 and 4.
Otherwise, it was a piece of cake.