About

This repo is about python implementation of SCFA executable patcher. It uses both clang and gcc compilers to combine advantages of both compilers.

Setup

See SETUP.md.

Run

To apply patcher on patch files run this command:

python main.py [path to config file]

config structure:

{
    // path to target folder. Can be either relative or absolute.
    // if relative path then it will be {config path}/{target_folder_path}
    "target_folder_path": "FA-Binary-Patches",
    // path to build folder. Defaults to "{target_folder_path}/build"
    "build_folder_path": null,
    // paths of input and output files
    "input_exe_path": "ForgedAlliance_base.exe",
    "output_exe_path": "C:\\ProgramData\\FAForever\\bin\\ForgedAlliance_exxt.exe",
    // path to clang++ compiler. Defaults to "clang++"
    "clang": "clang++.exe",
    // path to g++ compiler. Defaults to "g++"
    "gcc": "g++.exe",
    // path to linker. Defaults to "ld"
    "linker": "ld.exe",
    // flags for compilers
    "clang_flags": [
        "-pipe",
        "-m32",
        "-O3",
        "-nostdlib",
        "-Werror",
        "-masm=intel",
        "-std=c++20",
        "-march=core2"
    ],
    "gcc_flags": [
        "-pipe",
        "-m32",
        "-Os",
        "-fno-exceptions",
        "-nostdlib",
        "-nostartfiles",
        "-fpermissive",
        "-masm=intel",
        "-std=c++20",
        "-march=core2",
        "-mfpmath=both"
    ],
    "asm_flags": [
        "-pipe",
        "-m32",
        "-Os",
        "-fno-exceptions",
        "-nostdlib",
        "-nostartfiles",
        "-w",
        "-fpermissive",
        "-masm=intel",
        "-std=c++20",
        "-march=core2",
        "-mfpmath=both"
    ],
}

Patches folder structure

• /build: Here happens build for all source files. Patcher leaves address maps after build for debug purposes.
• /hooks: All files with asm that is injected by specified addresses.
• /include: Header files.
• /section: All files with patches that involve logic written with C/C++.
  • *.cpp files are built with g++
  • *.cxx files are built with clang++
  • Can contain nested folders
  • Can contain header files
  • Can contain .hook files
• config.json: Config file for patcher.
• section.ld: Main linker script.
• SigPatches.txt: File with signature patches. Replaces one binary sequence with another. Applied after build.
• ForgedAlliance_base.exe: Base executable of the game for patching.
• ForgedAlliance_exxt.exe: Result executable, run with debugger for more information in case of crashes.

Versions

Versions of compilers and linkers used.

clang++ compiler:

• clang version 21.1.0
• Target: x86_64-pc-windows-msvc
• Thread model: posix

ld linker:

• GNU ld (GNU Binutils) 2.39

g++ compiler:

• g++ (i686-posix-dwarf-rev0, Built by MinGW-Builds project) 13.2.0

python:

• 3.14.2

HumanUserCalls.py

A small script to convert x86 usercall/purge functions from IDA pseudo code into C ones made of GCC inline asm. Still suggested to check generated code as well as performing additional changes for asm.

Example

Input:

    char *__usercall Moho::DRAW_Rect@<eax>(
                          Vector3f *vec1@<eax>,
                          Vector3f *vec2@<ecx>,
                          int color@<edi>,
                          float thickness@<xmm0>,
                          CD3DPrimBatcher *batcher,
                          Vector3f *vec3,
                          CHeightField *heightField,
                          float a8)

Output:

    char* Moho::DRAW_Rect (
                Vector3f* vec1,
                Vector3f* vec2,
                int color,
                float thickness,
                CD3DPrimBatcher* batcher,
                Vector3f* vec3,
                CHeightField* heightField,
                float a8)
            {
            char* __result;
            asm(
                "push %[a8];"       
                "push %[heightField];"
                "push %[vec3];"
                "push %[batcher];"
                "movss xmm0, %[thickness];"
                "call ADDRESS;"
                "add esp, 0x10;"
                : "=a" (__result)
                : [vec1] "a" (vec1), [vec2] "c" (vec2), [color] "D" (color), [thickness] "m" (thickness), [batcher] "g" (batcher), [vec3] "g" (vec3), [heightField] "g" (heightField), [a8] "g" (a8)
                :"xmm0"
            );
            return __result;
            }

Debug.py

A script to debug game executable. Extracts from log crash data and uses build data to tell more information.

python Debug.py [Path to patches folder] [Command line arguments to run the game]

Example:

python ./Debug.py F:\GIT\FA-Binary-Patches ^
            C:\ProgramData\FAForever\bin\FAFDebugger.exe ^
            C:\ProgramData\FAForever\bin\ForgedAlliance_exxt.exe /init init-dev.lua /nobugreport /log C:\ProgramData\FAForever\bin\logs\game.log ^
            /EnableDiskWatch /showlog