Copying Files to a Disk Image

Once you have created the disk image, you can copy files to it prior to loading it in the emulator. To copy files, you can mount the image as a loop device and then copy the files to it, or you can use a utility such as mtools to copy the files directly to the image. The mtools package is available for Linux, Mac, and Windows.

Here, I will mount and copy files to emulator SD Card as a loop device.

In Unix-like operating systems, a loop device, vnd (vnode disk), or lofi (loopback file interface) is a pseudo-device that makes a file accessible as a block device.

Create a directory, named SD in my home.

Type the command in Terminal:
$sudo mount -o loop /home/eric/.android/avd/my_avd_GoogleAPIs_1.5.avd/sdcard.img /home/eric/sd

Where /home/eric/sd is the directory mounted to be accessed.
/home/eric/.android/avd/my_avd_GoogleAPIs_1.5.avd/sdcard.img is the SDCard image created for Android Emulator.

Now, you can create directory, copy files to the emulator's SDCard by SD.

$cd sd
$sudo mkdir pictures
$cd pictures
$sudo cp /home/eric/SDCard_16M.png .
$...

To know more details of the command mount, type
$man mount

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it's another approach, Create SD Card in Android Emulator and copy files into, in Eclipse, Emulator and DDMS.