4z0t / SCFA-python-patcher

Python implementation of SCFA patcher that uses clang compiler

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 folder with patches] [path to clang++ executable] [path to linker executable (ld)] [path to g++ executable]

Patches folder structure

• /build: Here happens build for all source files. Patcher leaves address maps after build for debug purposes.
• /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
• /hooks: All files with asm that is injected by specified addresses.
• define.h: Generated file for hooks to use.
• 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:

• version 18.1.8
• Target: x86_64-pc-windows-msvc
• Thread model: posix

ld linker:

• GNU ld (GNU Binutils) 2.40

g++ compiler:

• g++ (Rev6, Built by MSYS2 project) 13.1.0

python:

• 3.12.4

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