# PFES-ENG-004 — Firmware Transformation

**Status:** Active  
**Knowledge Cycle Stages:** Transform, Preserve

## Purpose

Convert recovered artifacts into deterministic engineering substrates while preserving transformation history.

## Engineering Problem

Encryption is only one barrier. Firmware may require decompression, decoding, byte-order correction, layout reconstruction, wrapper removal, or chained transformations.

## Historical Engineering Evolution

Transformation originally centered on decryption. Experience across firmware families showed that compression and other representation changes are equally important.

## Engineering Discoveries

- Transformation history is provenance.
- Canonical engineering substrates simplify downstream work.
- Multiple valid transformation paths may exist.

## Architectural Decisions

- Never overwrite inputs.
- Record each transformation.
- Keep intermediate artifacts until lifecycle review.
- Separate transformation from interpretation.

## Knowledge Produced

- Canonical substrates
- Transformation provenance
- Deterministic inputs

## Knowledge Consumed

- Recovered artifacts
- Transformation specifications
- Container knowledge

## Current Engineering State

Current transformation work includes decryption, decompression, normalization, decoding, and layout reconstruction. The architecture remains active as new families appear.

## Engineering Lessons

- Firmware frequently exists in or contains compression.
- Transformation chains themselves reveal packaging engineering.

## Negative Knowledge

Project Frankenstein no longer assumes:

- Stage 4 is only decryption.
- Intermediate transformed artifacts are always disposable.

## Current Implementations

- Stage 2 normalizer
- Stage 4 decryptor
- Family-specific transformation probes

## Future Implementations

- General transformation graph
- Automatic transformation identification
- Confidence propagation

## Open Questions

To be expanded during engineering review.

## Why This Chapter Exists

Every later subsystem depends on deterministic, traceable engineering substrates.
