Warning

⚠️ This port is now part of retro-go. Please follow these instructions, unless you want to flash SMW separately. ⚠️

Port of reverse engineered Super Mario World for the Game and Watch

All credits for reverse engineering goes to https://github.com/snesrev/smw

Build instructions

• Clone repository with submodules

git clone --recurse-submodules https://github.com/marian-m12l/game-and-watch-smw.git

• Install python requirements using pip

pip3 install -r requirements.txt

• Place your US ROM file named smw.sfc in smw/assets/.

• Compile and flash (e.g. on internal flash bank 2, leaving 1MB (out of 16) for stock firmware at the beginning of extflash)

make INTFLASH_BANK=2 EXTFLASH_SIZE_MB=15 EXTFLASH_OFFSET=1048576 ADAPTER=jlink OPENOCD=/path/to/patched/openocd-git/bin/openocd GNW_TARGET=mario flash

List of build flags

To control how the firmware is programmed:

Build flag	Description
INTFLASH_BANK	Which internal flash bank to program. 1 or 2.
EXTFLASH_OFFSET	Offset after which to program external flash. In bytes.
EXTFLASH_SIZE_MB	Allocated space in external flash. In MB.
LARGE_FLASH	Required for external flash chips > 16MB. Enables 32-bit addressing.

To control game options:

Build flag	Description
LIMIT_30FPS	Limit to 30 fps for improved stability. Enabled by default. Disabling this flag will result in unsteady framerate and stuttering.
OVERCLOCK	Overclock level: 0 (no overclocking), 1 (intermediate overclocking), or 2 (max overclocking). Default value: 2.
RENDER_FPS	Render performance metrics. Disabled by default.
ENABLE_SAVESTATE	Enable savestate support. This allocates 178kB of external flash. Disabled by default.

Backing up and restoring saves

ADAPTER=jlink OPENOCD=/path/to/patched/openocd-git/bin/openocd ./scripts/saves_backup.sh build/gw_smw.elf 
ADAPTER=jlink OPENOCD=/path/to/patched/openocd-git/bin/openocd ./scripts/saves_erase.sh build/gw_smw.elf 
ADAPTER=jlink OPENOCD=/path/to/patched/openocd-git/bin/openocd ./scripts/saves_restore.sh build/gw_smw.elf 

Applying additional features

Edit the FEATURE_* values in Makefile to enable additional features and bug fixes to the original game.

List of features

Build flag	Description
FEATURE_SAVE_AFTER_EACH_BEATEN_LEVEL	Save to SRAM after each beaten level (instead of saving after castle is beaten). SRAM save remains valid/compatible with emulators.

Button bindings

Description	Binding on Mario units	Binding on Zelda units
A button (Spin Jump)	PAUSE	START
B button (Regular Jump)	A	A
X/Y button (Dash/Shoot)	B	B
Select button (Use Reserve Item)	TIME	SELECT
Start button (Pause Game)	GAME + PAUSE	PAUSE
L button (Scroll Screen Left)	-	GAME + SELECT
R button (Scroll Screen Right)	-	GAME + START
Save savestate, if enabled	GAME + A	GAME + A
Load savestate, if enabled	GAME + B	GAME + B
Decrease Volume	GAME + Left	GAME + Left
Increase Volume	GAME + Right	GAME + Right
Decrease Brightness	GAME + Down	GAME + Down
Increase Brightness	GAME + Up	GAME + Up
Power Off	POWER	POWER
Power Off without saving savestate	POWER + PAUSE	POWER + PAUSE