Tested only on Rasbian (Debian Wheezy)
First, install all dependencies
sudo apt-get install git dialog
Then make directory for git and cloning the repo
git clone https://github.com/petrockblog/RetroPie-Setup.git
After finishnig that, you should have "retropie_setup.sh" file, start it with sudo.
You'll see a dialog, that asks you about "binary" or "source" installation, it's up to you, but the "source" installation takes about 2-3 hours.
So that's it, after installation you should have in your home "RetroPie" directory with some other directories inside.
pi@raspberrypi ~/RetroPie $ ls
EmulationStation emulatorcores RetroArch-Rpi roms SNESDev-Rpi
So let me explain, what is actually means.
emulatorcore -> separate emulators for respective platform from different developers.
RetroArch-Rpi -> Frontend for emulators (see http://themaister.net/retroarch.html), that allows use these emulators in the same way with same API.
EmulationStation -> GUI for RetroArch
roms -> copy your ROMs into directory
SNESDev-Rpi > see here http://petrockblog.wordpress.com/2012/07/03/snesdev-rpi-a-snes-adapter-for-the-raspberry-pi/
So, basically you have 3 different layers.
To start the emulators you'll need launch
How to use Gamepad
Plug your USB gamepad in to Raspberry PI (I've tested it with some generic PS-Clone Controller).
type this in console
sudo ~/RetroPie/RetroArch-Rpi/tools/retroarch-joyconfig | sudo tee -a /etc/retroarch.cfg
then type respective the button, that you see on the screen.
Using Gamepad to exit Emulator/Game
add this line at the end of /etc/retroarch.cfg
input_exit_emulator_btn = “11″
where "11" is you desired button, for example "11" for my controller equivalent R3 (right stick)
How to make a desktop link
create a file in "~/Desktop/emustation.desktop" with this content
Comment=EmulateStation, GUI for Retro Game Emulators
Of course you need change "Icon" with your image.
I can't see my ROMs.
check you "EXESTENSION" value in "EmulationStation" settings, it's case sensitive!
e.g for Sega it's ".smd", so it means a rom this name Sonic.SMD (not Sonic.smd) will not be displayed!
P.S. Thanks to Aloshi, petrockblog, ToadKing and others.