Compiling ScummVM/Wii

Compiling ScummVM for Wii or Gamecube

This page describes how you build a Wii or Gamecube binary from the ScummVM source tree.

First, you have to choose how to obtain the sources:

• a downloaded sources archive
• a SVN checkout (latest is trunk)

Required tools and/or libraries might change at times, and differences for various ScummVM versions are pointed out when necessary.

Mandatory tools and libraries

• devkitPPC as a build environment, please refer to its documentation how to set it up
• libogc and libfat

The latter two libraries are part of devkitPPC and are already installed with it. However, official ScummVM Wii and Gamecube binaries use unofficial versions, available via git here and here.

Reasons:

• libogc's malloc() has been modfied to utilize MEM2. Without this patch, a single binary with all game engines won't be able to run all games (like COMI) due to memory limits
• libfat gained a read-ahead cache, without it video sequences will stutter

Nevertheless, ScummVM should build just fine with either versions.

Versions differences

• v0.12.0 (first official version) is built with devkitPPC r15
• trunk (and eventually v0.13.0) changed to devkitPPC r16

Optional libraries

• Tremor (lowmem branch) to play .ogg audio files
• FLAC to play lossless .flac files

Again, you have two options:

Precompiled binaries

Get this archive and extract it in $DEVKITPRO/3rd/ you just created. The directory structure should look like

$DEVKITPRO/3rd/wii/include
$DEVKITPRO/3rd/wii/lib

and so on. The binaries will work on Wii and Gamecube.

Build the libraries yourself

These steps require some patching and fiddling with the required autotools and problems may arise (depending on your OS). Works for me (tm), good luck :P

Here's a a simple script to set up a shell for crosscompiling:

#!/bin/sh

PREFIX=${DEVKITPPC}/bin/powerpc-gekko-
export CC=${PREFIX}gcc
export CXX=${PREFIX}g++
export AS=${PREFIX}gcc
export LD=${PREFIX}gcc
export AR=${PREFIX}ar cru
export RANLIB=${PREFIX}ranlib
export STRIP=${PREFIX}strip
export OBJCOPY=${PREFIX}objcopy
export MACHDEP="-g -Os -Wall -DGEKKO -mcpu=750 -meabi -mhard-float -ffunction-sections -fdata-sections -fmodulo-sched"
export CFLAGS="${MACHDEP}"
export CXXFLAGS="${CFLAGS}"
export LDFLAGS="${MACHDEP}"

echo "./configure --host=ppc --disable-shared --prefix=${DEVKITPRO}/3rd/wii"

Save it to a file (like gekkoenv.sh) and run

. ./gekkoenv.sh

in your shell. Build systems should now use the correct tools.

Tremor

Get a SVN checkout (rev 15592 as of this writing):

svn co http://svn.xiph.org/branches/lowmem-branch/Tremor

patch it:

--- Tremor-vanilla/misc.h   2008-12-20 17:09:56.000000000 +0100
+++ Tremor/misc.h       2008-12-23 22:44:58.000000000 +0100
@@ -48,7 +48,7 @@

 #include <sys/types.h>

-#if BYTE_ORDER==LITTLE_ENDIAN
+#if 0
 union magic {
   struct {
     ogg_int32_t lo;
@@ -58,7 +58,7 @@
 };
 #endif

-#if BYTE_ORDER==BIG_ENDIAN
+#if 1
 union magic {
   struct {
     ogg_int32_t hi;

configure it:

./autogen.sh --host=ppc --disable-shared --prefix=${DEVKITPRO}/3rd/wii --enable-low-accuracy

and finally build & install it:

make
make install

FLAC

Get a tarball of the latest stable version here (v1.2.1 as of this writing), extract it, patch it:

diff -ur flac-1.2.1-vanilla/src/libFLAC/bitreader.c flac-1.2.1/src/libFLAC/bitreader.c
--- flac-1.2.1-vanilla/src/libFLAC/bitreader.c  2007-09-11 06:48:55.000000000 +0200
+++ flac-1.2.1/src/libFLAC/bitreader.c  2008-12-23 23:14:00.000000000 +0100
@@ -42,7 +42,7 @@
 #elif defined __MINGW32__
 #include <winsock.h> /* for ntohl() */
 #else
-#include <netinet/in.h> /* for ntohl() */
+//#include <netinet/in.h> /* for ntohl() */
 #endif
 #include "private/bitmath.h"
 #include "private/bitreader.h"
diff -ur flac-1.2.1-vanilla/src/libFLAC/bitwriter.c flac-1.2.1/src/libFLAC/bitwriter.c
--- flac-1.2.1-vanilla/src/libFLAC/bitwriter.c  2007-09-11 01:08:38.000000000 +0200
+++ flac-1.2.1/src/libFLAC/bitwriter.c  2008-12-23 23:13:59.000000000 +0100
@@ -42,7 +42,7 @@
 #elif defined __MINGW32__
 #include <winsock.h> /* for ntohl() */
 #else
-#include <netinet/in.h> /* for ntohl() */
+//#include <netinet/in.h> /* for ntohl() */
 #endif
 #if 0 /* UNUSED */
 #include "private/bitmath.h"

configure it:

./configure --host=ppc --disable-shared --prefix=${DEVKITPRO}/3rd/wii --disable-doxygen-docs --disable-xmms-plugin --disable-ogg --disable-oggtest --disable-rpath

and build & install the required parts:

make -C src/libFLAC
make -C src/libFLAC install
make -C include install

Compiling

This port doesn't utilize ScummVM's configure system, instead it comes with a simple Makefile. The port code can be found in two directories:

./backends/fs/wii/
./backends/platform/wii/

The former is a unified filesystem interface for ScummVM, the more interesting code is in the latter.

Change your working directory to the latter and open the Makefile in a editor. You'll find some variables on top of that file, adjust those to your liking. Everything should be self-explanatory, some are even documented. Here are some random hints:

• There is no support for dynamic libraries on the Wii or Gamecube, keep an engine toggle at STATIC_PLUGIN or disable it by just commenting that line
• Vanilla scalers are not supported by the Wii port
• zlib and MAD are part of libogc
• MPEG2 support has been dropped from the Wii port, if you want support for it, you have to cross compile libmpeg2

When you're done with the Makefile, save it and run make (GNU version). That's it, the build system is now building an .elf and a .dol.

Test the .dol by uploading it using wiiload via:

make upload

If you want to copy your compiled binary to SD, use the command

make dist

which generates the folder dist with all the required files to run it.