A cool guy named petrockblog made a script which automatically installs RetroArch, its cores, and ES. It also includes options for configuring your RPi and setting it up to boot directly into ES. You can find it here: https://github.com/petrockblog/RetroPie-Setup
EmulationStation has a few dependencies. For building, you'll need SDL 1.2, SDL_mixer, FreeImage, FreeType, and Boost.Filesystem, which can easily be obtained with apt-get:
There are also a few libraries already on the RPi (located in /opt/vc/, like the Broadcom libraries, EGL, and GLES). You can build EmulationStation by simply running `make`.
When first run, an example systems configuration file will be created at $HOME/.emulationstation/es_systems.cfg. This example has some comments explaining how to write the configuration file, and an example RetroArch launch command. See the "Writing an es_systems.cfg" section for more information.
1. Press a button on any device you wish to use. *This includes the keyboard.* If you are unable to configure a device, hold a button on the first device to continue to step 2.
2. Press the displayed input for each device in sequence. You will be prompted for Up, Down, Left, Right, A (Select), B (Back), Menu, Select (fast select), PageUp, and PageDown, Volume up and Volume down. If your controller doesn't have enough buttons to map PageUp/PageDown, it will be skipped.
*NOTE: If `~/.emulationstation/es_input.cfg` is present but does not contain any available joysticks or a keyboard, an emergency default keyboard mapping will be provided.*
The file `~/.emulationstation/es_systems.cfg` contains the system configuration data for EmulationStation. A system is a NAME, DESCNAME, PATH, EXTENSION, and COMMAND. You can define any number of systems, just use every required variable again. You can switch between systems by pressing left and right. They will cycle in the order they are defined.
The NAME is what ES will use to internally identify the system. Theme.xml and gamelist.xml files will also be searched for in `~/.emulationstation/NAME/` if not found at the root of PATH. It is recommended that you abbreviate here if necessary, e.g. "nes".
The DESCNAME is a "pretty" name for the system - it show up in a header if one is displayed. It is optional; if not supplied, it will copy NAME (note: DESCNAME must also *not* be the last tag you define for a system! This is due to the nature of how optional tags are implemented.).
The PATH is where ES will start the search for ROMs. All subdirectories (and links!) will be included.
**NOTE:** A system *must* have at least one game present in its PATH directory, or ES will ignore it.
The EXTENSION is a list of extensions ES will consider valid and add to the list when searching. Each extension *must* start with a period. The list is delimited by a space.
The COMMAND is the shell command ES will execute to start your emulator. As it is evaluated by the shell (i.e. bash), you can do some clever tricks if need be.
The following "tags" are replaced by ES in COMMANDs:
`%ROM%` - Replaced with absolute path to the selected ROM.
`%BASENAME%` - Replaced with the "base" name of the path to the selected ROM. For example, a path of "/foo/bar.rom", this tag would be "bar". This tag is useful for setting up AdvanceMAME.
The gamelist.xml for a system defines metadata for a system's games. This metadata includes an image (e.g. screenshot or box art), description, and name.
**Making a gamelist.xml by hand sucks, so a cool guy named Pendor made a python script which automatically generates a gamelist.xml for you, with boxart automatically downloaded. It can be found here:** https://github.com/elpendor/ES-scraper
If a file named gamelist.xml is found in the root of a system's search directory OR within `~/.emulationstation/%NAME%/`, it will be parsed and the detailed GuiGameList will be used. This means you can define images, descriptions, and different names for files. Note that only standard ASCII characters are supported (if you see a weird [X] symbol, you're probably using unicode!).
The path element should be the absolute path of the ROM. Special characters SHOULD NOT be escaped. The image element is the path to an image to display above the description (like a screenshot or boxart). Most formats can be used (including png, jpg, gif, etc.). Not all elements need to be used.
The best way to report a bug is to post an issue on GitHub. Try to post the simplest steps possible to reproduce the bug. Include files you think might be related (except for ROMs, of course). If you haven't re-run ES since the crash, the log file `~/.emulationstation/es_log.txt` is also helpful.
By default, EmulationStation looks pretty ugly. You can fix that. If you want to know more about making your own themes (or editing existing ones), read THEMES.md!