# PFES-ENG-006 — Firmware Topology

**Status:** Architectural refinement  
**Knowledge Cycle Stages:** Discover Structure

## Purpose

Map firmware structure before investing in detailed representation.

## Engineering Problem

Not every byte is executable code. Whole-payload disassembly wastes effort and creates false signal where data, tables, overlays, or resources are interpreted as instructions.

## Historical Engineering Evolution

Earlier workflows disassembled entire payloads first. Engineering review showed that topology should guide representation: identify executable regions, data regions, vectors, tables, dispatchers, and subsystem boundaries before detailed disassembly.

## Engineering Discoveries

- Engineering effort should follow topology rather than precede it.
- Topology is independent of full disassembly.
- Structure often remains stable across revisions.

## Architectural Decisions

- Discover structure before detailed representation.
- Distinguish observed topology from inferred topology.
- Use topology to target expensive analysis.

## Knowledge Produced

- Executable-region maps
- Data-region maps
- Vector and dispatcher maps
- Subsystem boundaries
- Dependency graphs

## Knowledge Consumed

- Transformed firmware
- Architecture knowledge
- Signatures and metadata

## Current Engineering State

Current topology targets include vectors, jump tables, SCSI dispatchers, services, memory regions, code/data boundaries, and hardware tables. Script changes will follow after PFES is satisfactory.

## Engineering Lessons

- A structural map increases signal-to-noise ratio.
- Topology can answer useful questions before function naming.

## Negative Knowledge

Project Frankenstein no longer assumes:

- Whole-image disassembly is always the correct first step.
- Disassembly automatically reveals code/data boundaries.

## Current Implementations

- Analyzer topology probes
- Manual disassembly review
- Family comparisons

## Future Implementations

- Topology-guided Stage 5A
- Automatic executable-region discovery
- Interactive maps

## Open Questions

To be expanded during engineering review.

## Why This Chapter Exists

Topology provides the map that prevents detailed engineering from exploring the wrong territory.
