# Eidolon in Rust: byte-exact Rust port of the Eidolon 64k intro

> Ports Eidolon, Poo-Brain’s winning PC 64k intro from Revision 2017, from its packed 60,928-byte Windows executable to Rust, with chapters on how the original binary works and a separate size-optimized build. The author reports that coordinated OpenCode and Claude Code agents, using Ghidra through the REA MCP server among other tools, captured a controlled-clock reference of the original and matched all 27,000 frame hashes and the full PCM. Exactness rests on the project’s own GPU-specific captures, and the port embeds the original’s data.

- Type: Case study
- Targets: Binary
- Category: Community REA investigations
- Relationship: Author-reported mixed workflow
- Sources reviewed: 2026-10-19
- Added to the catalog: 2026-11-09
- Original resource: <https://github.com/RovshanMuradov/eidolon-64k-rs>
- Primary source: <https://github.com/RovshanMuradov/eidolon-64k-rs/blob/5850c270f0f600c15c4cdfd2ac679a0e2b1f6984/README.md>
- Catalog page: <https://awesomerea.org/resources/eidolon-64k-rust-port-case/>
- Record JSON: <https://awesomerea.org/resources/eidolon-64k-rust-port-case/record.json>
- Chinese version: [简体中文](https://awesomerea.org/zh/resources/eidolon-64k-rust-port-case/index.md)

## Requirements & limits

- The Rust port targets i686-pc-windows-gnu. The documented Linux build uses Rust 1.97, MinGW-w64, Clang, Python, Wine and headless gamescope; the size build also needs NASM. Reference capture and size builds run on Linux, while macOS cannot run the intro.
- A new reference capture needs the original scene.org release archive and gm.dls from a Microsoft DirectX redistributable, both checked by SHA-256. The port embeds original tables, curves, shaders and music plus 15 Roland GM/GS samples; the size build reads system gm.dls.
- Under a controlled clock, the project reports matching 27,000 frame hashes and the full PCM. Shipped frame hashes fit its RTX 3070 Ti, driver and Wine setup; other GPUs need a local reference capture. Most fault-injection tests need 5.8 GB of unpublished raw reference data; 57 tests run without it. Native Windows playback and frame checks remain untested.
- The size build is 44,139 bytes versus the original 60,928 bytes; it did not reach the 32 KiB target. The author reports agent-led work with human goal setting and decisions.
- Rust code, tools and documentation are MIT or Apache-2.0. Bundled kkrunchy source is public domain. Original shaders, music, animation data and Roland samples retain their owners’ rights and are outside those licenses.

## Primary sources

1. <https://github.com/RovshanMuradov/eidolon-64k-rs/blob/5850c270f0f600c15c4cdfd2ac679a0e2b1f6984/README.md>
2. <https://github.com/RovshanMuradov/eidolon-64k-rs/blob/5850c270f0f600c15c4cdfd2ac679a0e2b1f6984/docs/rust/README.md>
3. <https://github.com/RovshanMuradov/eidolon-64k-rs/blob/5850c270f0f600c15c4cdfd2ac679a0e2b1f6984/docs/rust/verification.md>
4. <https://github.com/RovshanMuradov/eidolon-64k-rs/blob/5850c270f0f600c15c4cdfd2ac679a0e2b1f6984/docs/en/README.md>
5. <https://github.com/RovshanMuradov/eidolon-64k-rs/blob/5850c270f0f600c15c4cdfd2ac679a0e2b1f6984/size/README.md>
6. <https://github.com/RovshanMuradov/eidolon-64k-rs/blob/5850c270f0f600c15c4cdfd2ac679a0e2b1f6984/LICENSE-MIT>
7. <https://github.com/RovshanMuradov/eidolon-64k-rs/blob/5850c270f0f600c15c4cdfd2ac679a0e2b1f6984/LICENSE-APACHE>
8. <https://github.com/RovshanMuradov/eidolon-64k-rs/blob/5850c270f0f600c15c4cdfd2ac679a0e2b1f6984/size/packer/LICENSE>

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## About this entry

The description was reviewed against primary sources.
Original editorial content: MIT. Linked projects, papers and assets retain their own rights and licenses.