SkyWalker-1

The Genpix SkyWalker-1 is a standalone USB 2.0 DVB-S satellite receiver built around a Cypress FX2LP microcontroller and Broadcom BCM4500 demodulator. This project documents its complete internal architecture through Linux kernel driver analysis, Ghidra firmware reverse engineering across five firmware images, Windows BDA driver source review, and custom firmware development.

The result is a fully open-source technical reference covering every vendor command, register, GPIO pin, and data path — from the USB control transfers down to the I2C bit timing on the BCM4500’s indirect register protocol.

Supported modulations: DVB-S (QPSK), Turbo QPSK, Turbo 8PSK, Turbo 16QAM, Digicipher II (Combo, Split I/Q, Offset QPSK), DSS (QPSK), and DVB-S BPSK. Symbol rates from 256 Ksps to 30 Msps across a 950—2150 MHz IF range.

Note

DVB-S2 is not supported. The BCM4500 predates the DVB-S2 standard and contains no LDPC or BCH decoder hardware. This is a silicon limitation — no firmware update can change it. See the DVB-S2 Incompatibility section for the full investigation.

Explore the Documentation

Hardware

FX2LP + BCM4500 architecture, GPIO pin maps, RF specifications, and board block diagram.

Hardware Overview

USB Interface

Vendor command reference, boot sequence, configuration status byte, and endpoint layout.

USB Interface

BCM4500

Demodulator I2C protocol, indirect register access, tuning sequence, and GPIF streaming path.

Demodulator

LNB and DiSEqC

LNB voltage and tone control, DiSEqC 1.0/1.2 protocol, legacy Dish Network switches.

LNB Control

Firmware

Version comparison across five firmware images, custom v3.01.0 development, and storage formats.

Firmware Versions

Tools

Python utilities for RAM loading, EEPROM flashing, transponder tuning, transport stream analysis, and hardware debugging.

Firmware Loader

Project Scope

This documentation covers the complete reverse engineering of the SkyWalker-1 hardware and firmware:

• 5 firmware images decompiled in Ghidra: v2.06.04, Rev.2 v2.10.04, and three v2.13 sub-variants
• 30 vendor USB commands fully decoded with parameter formats and version-specific behavior
• Custom firmware (v3.01.0) built from scratch with SDCC + fx2lib, including 7 new diagnostic commands
• 13 Python tools for firmware management, satellite tuning, transport stream analysis, and hardware debugging
• I2C STOP corruption bug discovered and fixed through incremental debug modes on the FX2 controller

All source code, firmware binaries, analysis reports, and this documentation are available in the project repository.