# PFES-ENG-007 — Firmware Representation

**Status:** Mature implementation / evolving concept  
**Knowledge Cycle Stages:** Represent

## Purpose

Create deterministic engineering views of firmware that preserve traceability to source bytes.

## Engineering Problem

Raw binaries are difficult to reason about, but any representation can mislead if it obscures data/code boundaries or loses provenance.

## Historical Engineering Evolution

Representation began as full disassembly. It evolved into multiple views: targeted disassembly, memory maps, command inventories, topology maps, and dossiers.

## Engineering Discoveries

- No single representation answers every question.
- Representations exist for engineers; firmware remains authoritative.

## Architectural Decisions

- Representation follows topology.
- Every representation must map back to source offsets and addresses.
- Generated representations should be reproducible.

## Knowledge Produced

- Disassembly
- Memory maps
- Instruction inventories
- Analysis inputs

## Knowledge Consumed

- Topology
- Canonical substrates
- Architecture specifications

## Current Engineering State

Current HLDS implementation is Stage 5A, using MN103S-aware disassembly and structured inventories. Ghidra is not assumed available; objdump, custom scripts, and project-specific tooling remain valid paths.

## Engineering Lessons

- Targeted representation is more useful than indiscriminate output.
- Architecture-specific tooling should not define PFES.

## Negative Knowledge

Project Frankenstein no longer assumes:

- A disassembly is equivalent to understanding.
- One tool must be available for all engineers.

## Current Implementations

- hlds_stage5a_disassembler.py
- Custom MN103S tooling
- objdump-based workflows

## Future Implementations

- Topology-guided representation
- Additional architecture back ends
- Cross-linked address maps

## Open Questions

To be expanded during engineering review.

## Why This Chapter Exists

Representation converts structure into forms that humans and tools can analyze without replacing the firmware itself.
