GNUBoy SDL2 Port

As my repository has diverted quite a bit from the original code base - I have moved development of this project into a new repository. Please feel free to do whatever with this code (within the terms of the GPL). Feel free to fork it or check out the latest SDL2GNUBoy development below.

New Repository: https://github.com/AlexOberhofer/SDL2-GNUBoy

Overview

A Multiplatform Gameboy Emulator. Free Software.

My personal fork for experimentation. Based on GNUBoy and licensed under GNU GPLv2

SDL2 port now working on Linux and Windows

The scripts in the root directory are used by github actions workflow for building this repository. Read the code before you execute it...

Releases

The latest packaged releases are available under the associated workflow. This currently is only for Windows. If you use Linux/MacOS BUILD IT!!!!

Download Versioned Releases: (https://github.com/AlexOberhofer/sdl2gnuboy/releases)

Builds: (https://github.com/AlexOberhofer/sdl2gnuboy/actions) Note Builds only provided for windows via mingw64 for each commit

SDL2 GNUboy pre-compiled binaries will be provided with each release. The source is also provided on the release page and the binaries can be built from the source or from this repository.

v1.1.0 (Coming soon)

• Added Windows cross compilation

v1.0

• Supports Linux only

Screenshots

GB	GBC

Performance

The original core of GNUBoy is mainly unmodified except for a number of bugfixes I have ported into this fork.

Accuracy

A number of cpu buxfixes were ported from here

The emulator currently fails only one CPU instruction via blarggs test rom (Windows executable running in wine on Linux):

SDL2GNUBoy v1.1.0 Metrics

Coming Soon (Windows)

SDL2GNUBoy v1.0 Metrics

Here are a few demos running game intro loops and a unix process monitor (htop):

Note: Captures are from a Manjaro VM running on VMWare on Windows 10

Classic Gameboy: Pokemon Red

Gameboy Color: Pokemon Crystal

Legacy Metrics

Pre - fork GNUBoy performance metrics:

Note: The ASM code has now been removed from this repository

  PERFORMANCE

Here are some performance estimates i've gathered (given in percent
cpu utilization, running at full 60 fps)...

                                 Optimized C        Assembly
  AMD K6-2/450                       12%               8%
  Pentium/75                     (too slow)           70%
  SGI O2                             25%            (no asm)
  SGI Indy                           70%            (no asm)
  Sun Ultra60                       3-20%           (no asm)
  IBM S/390                      about 0.3%         (no asm)

Note that these figures were computed before sound was implemented.
Until the sound code is further optimized, gnuboy may run somewhat
slower than these numbers suggest.

Status

A working SDL2 build can be generated from the provided makefile. This is the build file I use for linux

Whats been done

• Builds and Runs on Linux (Tested and developed on Manjaro)

• Cross compiles on Linux into a Windows executable

• SDL2 control implementation (currently not rebindable)

• SDL1.2 rendering ported to SDL2 (Now uses gpu if possible and supports scaling)

• SDL1.2 sound ported to SDL2 (Needs a bit of work but its functional)

Todo

• Porting: The codebase is currently buildable on Windows/MacOS/*nix. I have built the SDL2 version of the codebase on each of those platforms, but I have not yet provided build scripts or releases for multiplatform. The SDL2 version only currently works on linux.

• Joystick / Controller Support

• SDL Sound rewrite

• SDL Keys rewrite (To support key rebinding)

Building

Build scripts are provided for both native unix applications and for cross compiling via mingw-w64 gcc

Build instructions are provided for both below:

Linux

This project requires GCC and SDL2 to build for linux. A Makefile has been provided.

Install SDL2 development libraries (Ubuntu):

$ apt-get install libsdl2-dev

Clone github repository:

$ git clone https://github.com/AlexOberhofer/gnuboy.git

Enter project directory:

$ cd gnuboy

Build:

$ make 

Run:

$ ./sdl2gnuboy ./rom

Windows (Cross Compiler)

SDL2 GNUboy can be cross compiled for Windows on Linux (or the Windows Linux Subsystem)

This requires mingw64-w64-gcc and the mingw SDL2 libraries.

These can be installed via the AUR or the SDL website (Extract and place contents in /usr/x86_64-w64-mingw32)

Install libraries (from AUR using yay)

$ yay mingw-w64-gcc

Install MinGW-w64-sdl2

$ yay mingw-w64-sdl2

Clone github repository:

$ git clone https://github.com/AlexOberhofer/gnuboy.git

Enter project directory:

$ cd gnuboy

Build:

$ make -f makefile.windows

Run

Windows:

• Drag and drop rom over executable

(Wine):

$ wine ./sdl2gnuboy.exe ./rom

Run (cmd):

$ ./sdl2gnuboy.exe ./rom

Controls

Controls are as follows:

P - PAUSE GAME (currently unsupported)

R - RESUME GAME (currently unsupported)

ESC - QUIT 

W - UP

S - DOWN

A - LEFT 

D - RIGHT 

Q - A

E - B

ENTER - START

BACKSPACE - SELECT

Developers

SDL2 GNUBoy

Alex Oberhofer

Acknowledgements

Cinoop Project

CTurt - Github

• [Github] (https://github.com/CTurt/Cinoop)

• [Website] (https://cturt.github.io/cinoop.html)

GNUBoy

• Thank you to the original GNUBoy developers. Please see the history branch for their versions. Legacy documentation can be found in the docs folder.

• [Website] (https://sourceforge.net/projects/gnuboy/)