How to run games programmatically?

coderkevin

Hello, I'm trying to get a system daemon to be able to start/stop games and emulationstation. What's the recommended way to do this?

UPDATE
I solved this problem with a script. You can use it too: https://github.com/coderkevin/mini-nes/tree/master/screen

The inspiration I've found for making this work is DaftMike's NESPi, but his script is pretty brute force. (https://github.com/imdaftmike/NESPi/blob/master/nespi.py) It seeks out and kills any and all emulator processes and emulationstation processes, and then uses openvt to run runcommand.sh on console 1 as root. However, I'm even having problems getting this to work right (joystick support not working for me).

I'm thinking there's got to be a better way to transition the system to start an emulator or restart ES. If there's not code to support it, I don't mind putting in some effort, just need a good push in the right direction.

(Here's the repo I've started to work with this, if anyone wants to see where I'm at or track progress: https://github.com/coderkevin/mini-nes)

Thanks!

dankcushions

@coderkevin i'm not sure about starting a game within ES.

...but, this might be a way to exit a game remotely: https://github.com/libretro/RetroArch/wiki/Network-Commands

this would only work for lr- emulators, though (which is most of them). retroarch may have a better way of doing this directly. i think RA might trap SIGTERM (rather than SIGKILL) cleanly, which might be a better way as it would save .SRM etc. i've not tested...

coderkevin

I'm dreaming up a better way to do this right now.

I'm thinking of replacing the autostart call to emulationstation, and calling a python script instead. And having that python script use subprocess.Popen to manage subprocesses to emulationstation and/or runcommand, then being able to send signals to those subprocesses without having to rely on console ps and kill calls.

For the actual switching of tasks, I'm thinking about watching a file under /dev/shm that could be edited by any other process with permissions to do so. This way, any external process could update that config to point to a rom file, then this python script would see the change and act accordingly.

Example:
Autostart runs script
Script by default start emulationstation
Script starts watching /dev/shm file.

Other process receives an event (GPIO button press, NFC tag, whatever)
Other process overwrites /dev/shm file to point to rom file.

Script detects that the /dev/shm file has changed and reads it.
Script reads rom in config file, sends signal to terminate current subprocess (emulationstation) and start new subprocess (runcommand)

I think something like this could be really useful for projects other than mine. If you're reading this and would file it helpful, let me know here. Whatever changes I do make will be available on my mini-nes github repo (or another repo that it references, I suppose)

coderkevin

Okay folks, I've written up a script to handle this exactly the way I described before.

It runs from the autostart.sh and watches /dev/shm/screen_manager.cfg for updates.
That way any other system process can create/modify that file and this script will respond by either starting the rom, or starting the dashboard.

Cheers!

https://github.com/coderkevin/mini-nes/tree/master/screen