desmume-docker

DeSmuME 0.9.11, the version of the course, in Docker, with HUD, GDB stub, sound, the controls of the course and the graphical output on the host (X11 / Wayland) or through VNC. It is used by the bmde run and bmde debug commands of bmde, but can be used on its own.

Build and installation

DeSmuME 0.9.11 is built from the sources of its Ubuntu package (the upstream sources and the patches of the package), with --enable-hud so the HUD (View -> HUD: FPS, input, lag counter...) works and with the GDB stub. The distribution packages lack them, or do not provide this version anymore.

scripts/download_assets.sh downloads those sources from Launchpad (and the ROM and the project used by the tests) into assets/, checking them against their pinned SHA-256 (see external resources of bmde). Then the scripts in src/ build and install DeSmuME into /URV/bmde/DeSmuME_0.9.11, with its environment (DESMUME, PATH) in /etc/profile.d/bmde-desmume.sh, taking the files only from src/, config/ and assets/. The image is built with them, and they install it in an Ubuntu / Debian host too:

scripts/download_assets.sh
src/install_desmume.sh
src/install_wrapper.sh  # $DESMUME/DeSmuME.exe and DeSmuME_dev.exe, used by the Makefiles of the course

Test the installation with the test/test_*.sh scripts. To build the image:

scripts/download_assets.sh  # The image is built from the assets
docker build -t aleixmt/desmume .

Configuration (controls, HUD)

DeSmuME is configured with a desmume.ini in the format written by DeSmuME for Windows, so the same file can be shared between Windows and this image. On start, the entrypoint translates it (desmume-ini2gtk) into the config of the Linux (GTK) frontend: key bindings from [Controls], and HUD, screen gap, rotation and SPU interpolation options. Other options are ignored.

• Default config: config/desmume.ini is installed at $DESMUME/share/bmde/desmume.ini. It is applied on the first run only (when no key bindings are saved yet in ~/.config/desmume), so changes made from the emulator window persist if ~/.config/desmume is a volume.
• Custom config: mount your own file at /config/desmume.ini. It is applied on every start, overriding saved changes:

docker run --rm -v "$PWD/desmume.ini:/config/desmume.ini:ro" ... aleixmt/desmume

Variable	Default	Description
DESMUME_INI	/config/desmume.ini	Custom config, applied on every start if found.
DESMUME_DEFAULT_INI	$DESMUME/share/bmde/desmume.ini	Default config, applied on first run.

Unassigned keys (code 0) keep the defaults of the Linux frontend (Debug: p, Boost: o, Lid: Backspace).

Sound

DeSmuME's audio can be played on the host through its PulseAudio-compatible server (PulseAudio or PipeWire's pipewire-pulse). Mount the host socket at /run/pulse/native and the entrypoint will use it automatically:

docker run --rm \
  -v "$XDG_RUNTIME_DIR/pulse/native:/run/pulse/native" \
  -v "$HOME/.config/pulse/cookie:/run/pulse/cookie:ro" \
  ... aleixmt/desmume

The cookie mount is only needed when the host server requires authentication (classic PulseAudio). Relevant environment variables:

Variable	Default	Description
DESMUME_USE_SOUND	1	0 disables sound (--disable-sound).
PULSE_SERVER	unset	Standard libpulse server address; overrides PULSE_SOCKET.
PULSE_SOCKET	/run/pulse/native	Where the host socket is mounted.
PULSE_COOKIE_FILE	/run/pulse/cookie	Where the host cookie is mounted, if any.

FAT image (CompactFlash card)

The programs of the course that read and write files (with libfat) need a FAT image as the CompactFlash card of the emulator. The entrypoint uses /fs/fat.img if it exists (DESMUME_CFLASH_IMAGE changes it). Create an empty one in fs/fat.img (it needs mkfs.fat, of the package dosfstools) and mount it:

scripts/create_fat_image.sh
docker run --rm -v "$PWD/fs:/fs" ... aleixmt/desmume

test/image/test_fat.sh tests this mechanism from outside the image (it needs Docker, mkfs.fat and mtools): it runs the ROM of filesystem-nds (built by scripts/download_assets.sh) with an empty FAT image, and checks the files that it writes into it:

scripts/download_assets.sh filesystem-nds.nds
test/image/test_fat.sh aleixmt/desmume