Nintendo 3DS

Nintendo 3DS Port
Latest Released Version	2.2.0
Supported Audio Options	MP3, OGG, FLAC, Uncompressed
Additional Webpage(s)	None
Maintainer(s)	bgK
Packager(s)	bgK
Forum	Port Forum
Status	Maintained
First Official Version	2.1.1

About

ScummVM has been ported to the Nintendo 3DS.

For more information, including how to install and use ScummVM, see the Nintendo 3DS user documentation.

Developer information

Compiling ScummVM

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.

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
libtheora	3ds-libtheora
curl	3ds-curl

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
• devkitpro-pkgbuild-helpers

Once you have the devkitpro-pkgbuild-helpers 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 $PORTLIBS_PREFIX
./configure --prefix=$PORTLIBS_PREFIX --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 helpers 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
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_PREFIX=$DEVKITPRO/portlibs/3ds
export PATH=$DEVKITARM/bin:$PATH
export PKG_CONFIG_PATH=$PORTLIBS_PREFIX/lib/pkgconfig
export PKG_CONFIG_LIBDIR=$PORTLIBS_PREFIX/lib/pkgconfig
export CFLAGS="-g -march=armv6k -mtune=mpcore -mfloat-abi=hard -O2
                    -mword-relocations -ffunction-sections -fdata-sections"
export CPPFLAGS="-I$PORTLIBS_PREFIX/include -I$CTRULIB/include"
export LDFLAGS="-L$PORTLIBS_PREFIX/lib"

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

In case you get an error about "namespace _3DS", edit the line in /opt/devkitpro/3dsvars.sh that reads

export CPPFLAGS="-D_3DS -I${PORTLIBS_PREFIX}/include -I${DEVKITPRO}/libctru/include"

and remove the "-D_3DS" part so that it reads

export CPPFLAGS="-I${PORTLIBS_PREFIX}/include -I${DEVKITPRO}/libctru/include"

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

export PKG_CONFIG_LIBDIR=$PORTLIBS_PREFIX/lib/pkgconfig

See above for $PORTLIBS_PREFIX.

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.

Debugging ScummVM

This section is based on information from Trac #11292.

When reporting crashes to the issue tracker, it is recommended that you capture a backtrace of the crash? It's a bit of a convoluted process but it's not possible to do much without it. It's described here if you are not familiar:

• Create a build of ScummVM using "./configure --host=3ds --disable-all-engines --enable-engines=scumm_7_8,he,sci32 --enable-all-engines --enable-debug"
• Get devkitARM from here: ​https://devkitpro.org/wiki/Getting_Started. You don't need to get the whole thing working, just the GDB debugger.
• Start ScummVM on your 3DS, go to the Rosalina menu (L+Down+Select), enable the debugger (Debugger options > enable debugger), go to the process list and select ScummVM (3dsx_app if you used the homebrew launcher). Take note of the IP address of your 3DS and the debugger port. They are displayed in the menu. For example, it might look like 192.168.1.87:4000. Close the Rosalina menu. If it closes ScummVM, try again, but open a dialog in ScummVM before opening the Rosalina menu (The keypress to close Rosalina is sometimes passed to ScummVM).
• On your computer in the devkitARM shell, run "arm-none-eabi-gdb /path/to/scummvm.elf" (with the location where you downloaded that file). Then, in GDB, enter "target remote 192.168.1.87:4000" (with your IP and port) to connect to the 3DS. Enter 'c' to resume execution.
• On the 3DS, reproduce the crash.
• On the computer, GDB should have trapped the error. Enter "thread apply all bt" to print a backtrace.

Please copy the backtrace into the ticket as well as other warnings or messages you may see in the debugger output.

In case you don't succeed in capturing a backtrace, please attach the crash dump from the Luma error screen (they are saved on the SD card in /luma/dumps).

It's also recommended that you attach a copy of the log file, which can be found at "sdmc:/3ds/scummvm/scummvm.log".