Medal of Honor: Frontline (Recompiled)

Medal of Honor: Frontline (Recompiled)

A native Windows build of Medal of Honor: Frontline (GameCube, USA), made from your own disc.

The game's program is statically recompiled to C with DolRecomp and compiled on your PC into a native module. That module runs on ModernGekko, a runtime built on Dolphin's hardware emulation (graphics, sound, input, disc access). This kit ships no game code or data. Setup reads everything from your disc.

What you need

• Windows 10 or 11, 64-bit.

• Medal of Honor: Frontline, USA release (GMFE69). Either:

  • a disc image as .iso or .gcm, or
  • a disc extracted with Dolphin (right-click the game > Properties > Filesystem > Extract Entire Disc). Setup then asks for the files\Moh2RelGC.elf inside it.

  Other formats (.rvz, .ciso, .gcz, .nkit) must be converted to ISO first: in Dolphin, right-click the game > Convert File > Format: ISO. Other regions and revisions are refused, because the recompiled program and its tuning are for this exact file.

• About 3 GB of free space (2 GB if you point it at an extracted disc) and an internet connection the first time. Setup downloads a portable clang (llvm-mingw) and Python, both pinned and checksum-verified.

Playing

Run MOHFrontline.exe. The first run opens a setup window that asks for your disc and builds the game. This takes 30 to 60 minutes on a laptop and about 15 minutes on a fast desktop. After that, the game starts straight away.

• MOHFrontline.exe --setup: choose another disc.
• MOHFrontline.exe --rebuild: rebuild the game from your disc.

Your settings and saves live in %LOCALAPPDATA%\MOHFrontline-Recomp, so updating the app keeps them. To keep everything in the app folder instead, put an empty portable.txt next to MOHFrontline.exe.

Controls

An Xbox-style (XInput) controller and the keyboard both work out of the box:

GameCube	Controller	Keyboard
Move (stick)	Left stick	Arrow keys
Look (C-stick)	Right stick	I J K L
Fire (R) / Aim (L)	Right / left trigger	W / Q
A (action)	A	X
B (melee)	X	Z
X (crouch) / Y (jump)	B / Y	C / S
Z (reload)	Right bumper	D
D-pad (weapons)	D-pad	T F G H
Start	Start	Enter

The mapping is Dolphin's, in user\Config\GCPadNew.ini under the data folder.

Widescreen

The kit turns on Dolphin's widescreen hack, so the 3D view is a true 16:9 picture. Menus and the HUD come out stretched sideways, which the hack can't avoid. For the original 4:3 picture, set AspectRatio = 0 and wideScreenHack = False in user\Config\GFX.ini.

Performance

How fast it runs depends on your CPU's single-core speed. On a 15 W laptop CPU (Intel i7-1355U), menus run at full speed, the intro movies at about 70% and missions at roughly two-thirds speed. Faster desktop CPUs do better. The kit pins the game to your fastest cores and turns off Windows power throttling for it. Graphics use Direct3D 11 at the native resolution, because the Vulkan and OpenGL backends draw striped movies on Intel Iris Xe. Both settings are in user\config.ini.

Two choices trade exactness for speed:

• Fast floating point: float math runs as plain host math, the same trade Dolphin's JIT makes. It doesn't keep the GameCube's FPSCR status flags or its 25-bit multiply rounding. This made gameplay about 20% faster and no difference has been seen.
• Profile-guided optimization: the shipped profile (kit\profile) was recorded in the first mission. It makes the compiled game about 20% faster.

How it works

1. Setup checks the disc ID (GMFE69) and the SHA-256 of files\Moh2RelGC.elf, the real game program. The disc's main.dol is only a boot stub.
2. kit\elf2dol.py converts that ELF into the DOL the recompiler reads.
3. runtime\dolrecomp.exe translates the DOL into about 90 MB of C.
4. kit\build_module.py compiles that C with clang (ThinLTO, -O3, the PGO profile) into module\gGMFE69_recomp.dll.
5. MOHFrontline.exe starts runtime\moderngekko-run.exe, which loads the module and runs the game.

runtime\msvcp140_atomic_wait.dll is a small wrapper (source in tzshim\). Some newer Windows time zones (for example Alberta's) are unknown to the system's ICU data, and Microsoft's C++ library then aborts the runtime at start. The wrapper supplies a zone name instead.

Source and license

GPL-3.0 (see LICENSE), like ModernGekko and DolRecomp. The runtime binaries in runtime\ are built from:

Project	Commit	Local changes
ExpansionPak/ModernGekko	edd460a	patches/ModernGekko-edd460a.patch: D3D11 backend option, speed in the title bar, PGO run fix
ExpansionPak/RecompCore (Dolphin fork, vendor/dolphin)	10f7ac4	patches/RecompCore-10f7ac4.patch: ppc_native_region_available stub
ExpansionPak/DolRecomp (vendor/dolphin/DolRecomp)	1bec355	patches/DolRecomp-1bec355.patch: direct cross-chunk calls enabled, fast floating point, env defaults

These were built with Visual Studio 2022 Build Tools. The MSVC runtime DLLs are Microsoft's redistributables.

Made with the help of an AI coding assistant. This is a fan project, not affiliated with or endorsed by Electronic Arts or Nintendo. You need your own copy of the game.