How to build and test JSMESS 0.153

Steve Layton edited this page Feb 25, 2015 · 14 revisions

JSMESS is now synched to the post-0.153 builds of MESS.

Like emscripten, the MAME GitHub mirror is a submodule of JSMESS, and can be updated independently.

JSMESS requires all the normal emscripten prerequisites (Python 2.7.3+, Node.js 0.8+, Java if you want to run the Closure compiler), as well as nm. nm can be found in the binutils package in Debian/Ubuntu.

To build and test JSMESS, you will run the commands below to:

  • Clone JSMESS (~100MB)
  • Download emscripten and MAME (~100MB and ~300MB, usually pinned to versions of each known to work)
  • Emscripten now uses a fastcomp engine and as of April 2014 needs additional steps to work with CLANG. These steps below come from this document:
  • Compile MESS and generate necessary helper files.
  • For the platform(s) you are going to test, copy BIOS and game files into the bios and games directories (you can find MESS BIOS ROM files on, games are elsewhere)
  • Generate a set of platform makefiles
  • Build that platform
  • Test that platform

Time: Most of these processes are fast, but the compilation of CLANG and MAME will take tens of minutes. Ultimately, these fastcomp steps will not be necessary once CLANG updates.

RAM: A recent attempt to compile JSMESS on a 2GB RAM VM failed. Consider having at least 4GB RAM available.

git clone
cd jsmess
git submodule update --init --recursive
cd third_party/emscripten
git checkout incoming
cd ..
git clone
cd emscripten-fastcomp
git checkout incoming
cd tools
git clone clang
cd clang
git checkout incoming
cd ../..
mkdir build
cd build
../configure --enable-optimized --disable-assertions --enable-targets=host,js
make -j 4

Because you made a very unusual LLVM setup doing this, you then need to go into the ~/.emscripten file and edit the LLVM_ROOT variable to wherever jsmess/third_party/emscripten-fastcomp/build/Release/bin/ is. Then, continue.

cd ../../../helpers/

This will kick off a full MESS build and generate necessary helper files. You do have to run the helper scripts from inside the helpers directory.

If you also intend to compile MAME systems, you will also need to do:

cd ../mamehelpers/

Copy your BIOS files into bios and your game files into games. Then, from either helpers (for MESS systems) or mamehelpers (for MAME systems):


where PLATFORM is the name of the system you want to make. It needs to be a valid MESS system name. For names, see the "name", "parent" and "sourcefile" columns here:

This will generate files suitable for creating a JSMESS version, but you can also use them as normal MESS tiny.mak files, and go into third_party/mame and run make TARGET=mess SUBTARGET=PLATFORM (again, replacing PLATFORM with the system name) to build a native, tiny MESS version for that platform.

Finally (for MESS systems):

cd ..

where PLATFORM is the name of the system, and FILENAME is the filename of the game to test with (game files go in games).

Then, browse the resulting build directory to try it out. Report successes and failures in IRC, please.

Some MESS systems, and all MAME systems, do not require pre-loading a game to test with, as their BIOS contains all their software. In those cases, leave out the GAME=FILENAME part.