Compiling ScummVM/Nintendo 3DS

Compiling ScummVM for Nintendo 3DS

Prerequisites

Latest version of devkitPro, which comes with devkitARM and libctru
citro3d thorugh devkitPro's pacman
Optional: You should compile third-party libraries for the 3ds (commonly referred to as portlibs in the devkitPRO community). Some games requires these to operate properly.

Compiling third-party libraries

It is strongly recommended that you use devkitPro's pacman in order to get the most recent portlibs for your build. Instructions for accessing these binaries can be found here: https://devkitpro.org/wiki/devkitPro_pacman

The following libraries can be downloaded with pacman:

Library	Package
zlib	3ds-zlib
libpng	3ds-libpng
libjpeg	3ds-libjpeg-turbo
freetype2	3ds-freetype
libmad	3ds-libmad
libogg	3ds-libogg
tremor	3ds-libvorbisidec
flac	3ds-flac
curl	3ds-curl
libtheora	3ds-libtheora

At the moment of writing, the version of freetype2 packaged by devkitPro has an issue where it allocates too much data on the stack when ScummVM loads GUI themes. As a workaround, an older version can be used. Version 2.6.5 is known to work well. The instructions below can be used to compile it.

At the moment of writing, faad is not in the devkitPro 3DS pacman repository. It can be compiled by following the instructions in the section below, in case it cannot be found through pacman.

The following pacman packages are also recommended:

3ds-dev
dkp-toolchain-vars

Once you have the dkp-toolchain-vars package, you should be able to find the following scripts in your /opt/devkitpro folder:

devkitarm.sh
3dsvars.sh

Run them one after the other with source in order to setup your environment variables for cross-compiling:

source /opt/devkitpro/devkitarm.sh
source /opt/devkitpro/3dsvars.sh

After that, you can download the libraries you want to cross compile, run any autoconf scripts that they may have, and then they can usually be built with the following steps from their source directory:

mkdir -p $PORTLIBS
./configure --prefix=$PORTLIBS --host=arm-none-eabi --disable-shared --enable-static
make
make install

Most libraries used can be compiled with same commands and configuration flags.

Manually setting up the environment

In case you don't have the dkp-toolchain-vars package downloaded, you can use the following to set-up your environment variables.

It is assumed that you have these variables already set up. If not, then do so:

DEVKITPRO	Your root devkitPro directory (usually /opt/devkitpro)
DEVKITARM	Your root devkitARM directory (probably same as $DEVKITPRO/devkitARM)
CTRULIB	Your root libctru directory (probably same as $DEVKITPRO/libctru)

In the source directory of the library:

export PORTLIBS=$DEVKITPRO/portlibs/3ds
export PATH=$DEVKITPRO/tools/bin:$PORTLIBS/bin:$DEVKITARM/bin:$PATH
export PKG_CONFIG_PATH=$PORTLIBS/lib/pkgconfig
export PKG_CONFIG_LIBDIR=$PORTLIBS/lib/pkgconfig
export CFLAGS="-g -march=armv6k -mtune=mpcore -mfloat-abi=hard -O2
                    -mword-relocations -ffunction-sections -fdata-sections"
export CXXFLAGS="$CFLAGS"
export CPPFLAGS="-D_3DS -D__3DS__ -I$PORTLIBS/include -I$CTRULIB/include"
export LDFLAGS="-L$PORTLIBS/lib -L$CTRULIB/lib"
export TOOL_PREFIX=arm-none-eabi-
export CC=${TOOL_PREFIX}gcc
export CXX=${TOOL_PREFIX}g++
export AR=${TOOL_PREFIX}gcc-ar
export RANLIB=${TOOL_PREFIX}gcc-ranlib
export LIBS="-lctru"

Compiling ScummVM

Do the following in a fresh terminal.

In case you get a "compiler not found" message, add the toolchain's executables to your PATH:

export PATH=$DEVKITARM/bin:$PATH

Note: In more recent codebases of ScummVM, you may or may not need to set the following beforehand:

export PKG_CONFIG_LIBDIR=$PORTLIBS/lib/pkgconfig

See above for $PORTLIBS.

ScummVM doesn't provide the CA certificates bundle required by the cloud synchronization features. You need to download it from the curl website: https://curl.haxx.se/ca/cacert.pem, and instruct the build system to package it in the binary:

export DIST_3DS_EXTRA_FILES=/path/to/cacert.pem

The name of the file must be cacert.pem.

From the root of the scummvm repository:

./configure --host=3ds --enable-plugins --default-dynamic
make

Additionally compile to specific formats to be used on the 3DS:

make scummvm.3dsx
make scummvm.cia

Assuming everything was successful, you'll be able to find the binary files in the root of your scummvm folder.

Note: for the CIA format, you will need the makerom and bannertool tools which are not supplied with devkitPro.

Note: using dynamic plugins as suggested is required when building with most or all of the game engines enabled in order to keep the memory usage low and avoid stability issues.