If you need to develop and test application on Eclipse for Android v4.x you could encounter a problem with virtual machine starting followed with some of messages below:
Unable to find a 'userdata.img' file for ABI armeabi to copy into the AVD folder.
ERROR: This AVD's configuration is missing a kernel file
It means that you do not have installed Android v4 system image.
What is ARM EABI v7a System Image
Basically, ARM EABI v7a System Image is the kernel image. You must install it, otherwise the virtual machine won't start.
How to install ARM EABI v7a System Image
Method #1: ARM EABI v7a System Image automatic installation
1) Window > Android SDK Manager
2) Android SDK Manger will perform checking for new updates
3) Select ARM EABI v7a System Image
4) Click Install packages...
5) Select Accept All and click Install
6) Restart Eclipse
Method #2: ARM EABI v7a System Image manual installation
Upgrading Android platform in most cases passes smoothly, but our experience tells us that downloading Android ARM EABI system image using Android SDK Manger sometime can't be installed and even causing Windows OS freezing!
1) Close Android SDK Manger
2) Download ARM EABI v7a System Image manually (https://dl-ssl.google.com/android/repository/sysimg_armv7a-14_r01.zip)
3) Copy downloaded .zip file to temporary directory of Android SDK installation directory (default path on Windows is “C:\Program Files\Android\android-sdk\temp”)
4) Start SDK Manger and select "ARM EABI v7a System Image" under Android 4.x.x (API xx)
5) Click Install
6) The manager will not download the package; it will be installed from temporary directory instead.