From Gumstix User Wiki
The fastest way to test Android on a Gumstix Overo is using prebuilt images loaded on a bootable microSD card. This page explains where to find prebuilt images and how to make a bootable microSD card. Otherwise, check out how to build Android from source.
Android in Four Commands
First, some useful tools should be downloaded. Those building from source will have already downloaded this git repository to the utils directory.
$ git clone git://github.com/gumdroid/android-utils.git utils
$ source utils/gumget
Next, insert a microSD card (at least 1GB by default) and confirm the path of the microSD card. For example,
might yield a path of
Now, make a bootable microSD card (optionally, see this procedure):
$ sudo utils/mkandroidsd /dev/mmcblk0 .
(note the trailing '.'; this is the path to the directory where the downloaded files are stored)
Note: If present, the contents of a directory named Media located alongside the downloaded files will be copied on to the third partition. This is useful to load sample media onto your system.
Finally, remove the microSD from your computer, insert it into your Gumstix COM, and let it boot. Note that many packages are configured during the first boot so it may seem like your system hangs for approximately five minutes on the animated android text log screen. Subsquent boots should complete under a minute.
For information on using this port of Android, see here.
Note: If your board fails to load the kernel, you may need to reset your u-boot environment variables as the boot script is not being run. To do this, issue this command at the u-boot prompt on startup.
$ nand erase 240000 20000