An alternative firmware for Supercard GBA flash carts
This project aims to provide a more modern and better firmware for Supercard flash carts (which are still widely used and very cheaply available). The goal is to add many features only present in more expensive or sophisticated flash carts. Unfortunately we are limited to the actual hardware so certain features are impossible or very complex to implement.
Find the website and documentation at https://superfw.davidgf.net/
The firmware can be chain-loaded using another firmware (ie. the default SuperCard firmware or SCFW) and loaded as a regular game. It can also be installed on the internal flash device. Installing it enables some nice features such as SDHC and exFAT compatibility.
To install the firmware you can simply load it first, and then use SuperFW to flash itself on the flash. You will need to enable flashing in the Info tab and then pick the .fw file and flash it. It is strongly recommended to reboot your GBA after flashing.
Flashing is also possible using an NDS. This is particularly useful if you brick your Supercard (ie. interrupting flashing, low battery conditions and similar situations could cause a bad flash). You will need an NDS device and a Slot-1 cart as well. Download the .nds ROM for your Slot-1 cart at https://github.com/davidgfnet/superfw-nds-flasher-tool/releases/ and launch it with your Supercard on your Slot-2. You should be able to flash (as well as backup) your flash.
All SuperFW related files are stored under "/.superfw" at the root of the card. The following files are usually created:
- .superfw/settings.txt: User settings, loaded on startup.
- .superfw/ui-settings.txt: UI settings, loaded on startup.
- .superfw/recent.txt: Recently played ROMs, in order.
- .superfw/pending-save.txt: SRAM save information (temp file).
- .superfw/pending-sram-test.txt: SRAM test flag (temp file).
Other noteworthy paths:
- .superfw/config/: Per-ROM load configuration.
- .superfw/patches/: Patch cache (created by PatchEngine).
- .superfw/cheats/: Cheat database, contains .cht files.
- .superfw/emulators/: Emulator ROMs, used to play other device's ROMs.
GameBoy and GameBoy Color ROMs can be played by using the built-in Goombacolor emulator binary. Picking any .gb/.gbc file will load the emulator and the ROM and start its execution.
Other devices can also be played as long as the right emulator is installed in the SD card (and supported by SuperFW).
The firmware contains a patch database to patch several features. A custom database can also be loaded from the SD card and used instead (so more games and improvements can be added). The patches contain information about:
- WaitCNT patches: Also called white/black screen patches, prevent games from updating the WAITCNT waitstates (the supercard has a slow memory). Without a correct patch the game won't even boot.
- Flash/EEPROM offsets: Indicate where the relevant storage routines are so that they can be patched and converted to SRAM storage.
- IRQ handler patches: Used to patch user IRQ handler routine and install a custom one. Used to enable in-game menu.
- RTC patches: Used for games that contained an RTC IC in theri cart, to keep track of time (both time and date). There's only a handful such ROMs.
These patches are generated mostly automatically, check out the patch repo at: https://github.com/davidgfnet/gba-patch-gen
SuperFW features an in-game menu that allows users to pause the current game and perform certain actions such as:
- Resuming and resetting the game
- Going back to the SuperFW menu (witout having to reboot your GBA)
- Handling saves (for games that allow saving)
- Creating and restoring savestates
- Applying/using cheat codes
- Changing the RTC time (for games that use an RTC)
This menu is a bit of a hack that requires patching the ROM to work. For this reason, some games won't work well with it or will suffer from bugs (usually graphical bugs). In this case it is advised to not use the in-game menu.
Many graphical glitches will result in the screen being "offseted" to the left/right/up/down. In many cases this is not an issue (besides making it harder for the user to see and play) and it goes away when entering a new zone/level/menu. This is due to the GBA featuring some "write-only" registers, that is, registers that can be written but never read back. For this reason we cannot properly save and restore said registers.
Save games are stored in the cart's SRAM and preserved by the cart battery (note that if the battery is dead the game will be lost). On reboot SuperFW will write the savegame to the SD card to preserve it and allow loading another save game.
When using the in-game menu, you might enter the menu and select any of the saving options, which will write the save to the SD card. This is a good way to save your games if you prefer to manually handle save files (ie. disabling autosave and manually choosing when to save).
For Flash-based games (around 300 games) and EEPROM-based games (around 1400 games) it is possible to patch games so that they write directly to the SD save game, this is called Direct-Saving mode. This makes saving more reliable (no need for a battery!) and simpler to use (no need to reboot to ensure saving or using the in-game menu). Games that use Flash or EEPROM will display an option for direct-saving (this is the default choice in Auto mode).
The following restrictions apply to the firmware due to memory/storage/cpu constraints:
- Maximum ROM size: 32MiB (Supercard's memory size)
- File path and name limit: 255 utf-8 bytes (not exactly characters!)
- Maximum number of files+dirs in a directory: 16384
Most of SuperFW was written by davidgf and is published under GPL license. Some components use third party code, such as: nanoprintf (public domain), heapsort (3-BSD), fatfs (1-BSD-like) and apultra/upkr (only used at build-time). Some linkerscript/crt0 code was adapted from AntonioND's work under CC0.