GMLoader-next:

A repository for further experimenting with elf loading and in-place patching of android native libraries on non-android operating systems.

This attempts to fix several shortcomings the previous versions of GMLoader had, offering a more compliant compatibility layer, and an elf loader that supports even more relocation types.

Disclaimers:

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This repository contains a lot of incomplete, experimental and untested code, and behavior is not guaranteed to match specifications, specially when it comes to the fake JNI implementation.

Corrections, fixes, issue reports and optimizations are always welcome.

Building and Deploying [example]:

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First clone the repository and all of it's submodules:

git clone <repository url> --recursive

Now build the project for your desired target platforms, the following build options are available:

• ARCH: Specify the architecture, e.g.: aarch64-linux-gnu or arm-linux-gnueabihf
• LLVM_FILE: Specify the LLVM Clang library file, e.g.: /usr/lib/llvm-9/lib/libclang-9.so.1 for clang-9.
• LLVM_INC: Specify the path for LLVM includes for your architecture, e.g.: aarch64-linux-gnu.
• OPTM: Specify the optimization flags, e.g.: -O3, -Os or -Og -ggdb.
• USE_FMOD: Whether to build FMOD Extension support.
  • You need to extract fmodstudioapi.tar.gz into 3rdparty/fmod for FMOD support.

make -f Makefile.gmloader ARCH=aarch64-linux-gnu

As an example, you can build this using Debian Bullseye to target older platforms:

make -f Makefile.gmloader \
ARCH=aarch64-linux-gnu \
LLVM_FILE=/usr/lib/llvm-11/lib/libclang-11.so.1 \
LLVM_INC=/usr/aarch64-linux-gnu/include/c++/10/aarch64-linux-gnu \
-j$(nproc)
python3 scripts/generate_libc.py aarch64-linux-gnu --llvm-includes /usr/aarch64-linux-gnu/include/c++/10/aarch64-linux-gnu --llvm-library-file "/usr/lib/llvm-11/lib/libclang-11.so.1"

Now, to deploy, you must copy the lib redist folder in the application's folder. Those files are dependencies of the guest Android application (e.g. the runner) and are used to provide a more accurate Android environment for the guest application.

See the related documentation for reference.

Debugging:

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Git info is baked into the binary and can be pulled with strings gmloadernext.${DEVICE_ARCH} | grep -E (GIT_|BUILD_), for example:

root@SD865: strings gmloadernext.${DEVICE_ARCH} | grep -E (GIT_|BUILD_)
BUILD_DATE_20250103_hh:mm:ss
GIT_BRANCH_master
GIT_HASH_a4b6187a6757cd8cc5eb4af958d2044e2543677b

The android libraries can be debugged with gdb using a breakpoint trick - check out the provided debugging example.

For this to be possible, you must extract the libraries from the APK into the application's library folder following the same structure as you would on the APK.

Config file

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GMLoader-next can load a json formatted configuration file using the -c option. For exemple ./gmloadernext.aarch64 -c gmloader.json

gmloader.json:

{
    "save_dir" : "gamedata",
    "apk_path" : "my_game.apk",
    "show_cursor" : false,
    "disable_controller" : false,
    "disable_depth" : false,
    "force_platform" : "os_windows"
}

When no configuration file is present the default values are:

Parameter name	Default value
save_dir	./
apk_path	game.apk
show_cursor	true
disable_controller	false
disable_depth	false
force_platform	os_android

Supported values for force_platform are:

• os_unknown
• os_windows
• os_macosx
• os_ios
• os_android
• os_linux
• os_psvita
• os_ps4
• os_xboxone
• os_tvos
• os_switch

License:

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This is free software. The source files in this repository are released under the GPLv2 License, see the license file for more information.