Windfish is a disassembler for Gameboy ROMs that can generate RBGDS-compatible assembly code.
This project was initiated to support archaelogical efforts aimed at understanding the implementation details behind Link's Awakening for the original Gameboy. The project has since grown to be a general disassembler for Gameboy ROMs.
The name "Windfish" is a reference to the main focus of the Link's Awakening storyline.
The core design principle of the Windfish disassembler is to maximize legibility of generated assembly code with minimal configuration.
Windfish supports several powerful features for disassembling Gameboy ROMs, including:
- Control-flow disassembly: Able to follow branches in control flow in order to distinguish code from binary data.
- Memory bank awareness: Bank changes are monitored so that jumps to 0x4000-0x7999 memory regions can move to the correct bank.
- Regions: Text, image (2bpp, 1bpp), and data regions can be registered enabling a rich representation of the disassembly in the Windfish IDE.
- Data types: Custom datatypes can be registered and, when detected, automatically referenced in the generated assembly to improve code readability.
- Globals: Global variables can be registered and referred to within the generated assembly.
- Macros: Common assembly patterns can be registered and, when detected, generated as RGBDS macros.
- Scope awareness: Contiguous blocks of scope are inferred during disassembly.
The Windfish disassembler is best invoked through the IDE which is integrated closely with the powerful Sameboy emulator and debugger.
Features of the IDE:
- Full Sameboy debugger integration: See https://sameboy.github.io/debugger/ for complete documentation on the debugger.
- Full Sameboy emulation: This enables a tight feedback loop where emulation can be used to increase your understanding of the disassembly.
- Configuration editing: Edit regions, data types, globals, and macros from the IDE.
- Labeled callstack: The labels are read directly from the full-context disassembly.
- Tooltip documentation: Documentation for instructions can be seen by hovering over the instruction.
- Function scope visualization: Function scopes are shown as a contiguous line alongside the source.
- Selected bank visualization: The selected bank is shown alongside each instruction.