piratesephiroth / sotn-decomp

Decompilation of Castlevania: Symphony of the Night (PSX+Saturn)

Castlevania: Symphony of the Night Decompilation

A work-in-progress decompilation of Castlevania Symphony of the Night for Sony PlayStation 1 and Sega Saturn. It aims to recreate the source code from the existing binaries using static and/or dynamic analysis. The code compiles byte-for-byte to the same binaries of the game, effectively being a matching decompilation.

It currently supports the following versions of the game:

• us the reference build with the serial number SLUS-00067
• hd an unreleased PS1 Japanese build found in Castlevania: Dracula X Chronicles game data
• saturn the port created by an external development team

This repo does not include any assets or assembly code necessary for compiling the binaries. A prior copy of the game is required to extract the required assets.

Bins decomp progress

File name	Code coverage	Decomp functions	Description
SLUS_000.67	N/A	N/A	Shared libraries
DRA.BIN			Game engine
BIN/RIC.BIN			Playable Richter
BIN/WEAPON0.BIN			Equippables
ST/CEN/CEN.BIN			Center
ST/DRE/DRE.BIN			Nightmare
ST/MAD/MAD.BIN			Debug Room
ST/NO3/NO3.BIN			Entrance (first visit)
ST/NP3/NP3.BIN			Entrance
ST/NZ0/NZ0.BIN			Alchemy Laboratory
ST/SEL/SEL.BIN			Title screen
ST/ST0/ST0.BIN			Final Stage: Bloodlines
ST/WRP/WRP.BIN			Warp Room
ST/RWRP/RWRP.BIN			Warp Room (reverse)
SERVANT/TT_000.BIN			Bat Familiar

Code coverage means how many bytes of code have been successfully converted from assembly into C code, while decomp function is how many functions have been successfully decompiled.

Useful links

• Build guide
• Decompilation guide
• Progress report

Decompiling a game is a mastodontic task. If you have some basic programming skills, please join us in this journey. Any contribution will be very appreciated!

Special thanks

This project is possible thanks to the hard work of tools provided by the Decompilation community:

• mips2c from @matt-kempster to decompile MIPS assembly into C. This has proven to be more accurate than Hexrays IDA and Ghidra.
• splat from @ethteck to disassemble code and extract data with a symbol map. This tool provides the fundamentals of the SOTN decomp.
• asm-differ from @simonlindholm to know how the decompiled code compares to the original binary.
• decomp-permuter from @simonlindholm to pick different versions of the same code that better matches the original binary.
• maspsx by @mkst to replicate the customized assembler used in the official PSX SDK.
• decomp.me by @ethteck, @nanaian and @mkst to provide a collaborative decompilation site to share and contribute to work-in-progress decompiled functions.
• frogress by @ethteck to store and retrieve progression data.
• esa-new by @mkst as an inspiration on how to set-up a PS1 decompilation project.
• oot as an inspiration of what it is possible to achieve with a complete decompiled video game.