Dynamic side loading of cores

[dragoonDorise]

Guidelines

1. Rebase before opening a pull request
2. If you are sending several unrelated fixes or features, use a branch and a separate pull request for each
3. If possible try squashing everything in a single commit. This is particularly beneficial in the case of feature merges since it allows easy bisecting when a problem arises
4. RetroArch codebase follows C89 coding rules for portability across many old platforms check using C89_BUILD=1

Description

This PR allows RetroArch Android to sideload cores using the LIBRETRO argument, you can pass a path in that argument and the code will copy that core to /data/user/0 if it's not there already.

Launch command example:

am start
  -n com.retroarch/com.retroarch.browser.retroactivity.RetroActivityFuture
  -e ROM {file.path}
  -e LIBRETRO /storage/emulated/0/RetroArch/cores/gambatte_libretro_android.so
  -e CONFIGFILE /storage/emulated/0/Android/data/com.retroarch/files/retroarch.cfg
  -e IME com.android.inputmethod.latin/.LatinIME
  -e DATADIR /data/data/com.retroarch
  -e APK /data/app/com.retroarch-1/base.apk
  -e SDCARD /storage/emulated/0
  -e EXTERNAL /storage/emulated/0/Android/data/com.retroarch/files

That command will copy /storage/emulated/0/RetroArch/cores/gambatte_libretro_android.so to /data/data/com.retroarch/cores/mgba_libretro_android.so and use it to launch the provided {file.path}

This has been tested with launchers like ESDE that uses the current LIBRETO argument and has been proved to work too if the user has manually downloaded the core.

-e LIBRETRO /data/data/com.retroarch/cores/mgba_libretro_android.so

In a nutshell, you can use the data/data path or a custom path, the code takes care of it.

Related Issues

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Related Pull Requests

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[hizzlekizzle]

Let me see if I can get some discussion going on this.