Firmware Loader

Two complementary tools handle firmware on the SkyWalker-1: fw_load.py loads firmware into FX2 RAM for testing, and fw_dump.py extracts firmware and device information from a running device.

Both tools require pyusb and typically need root access (or appropriate udev rules) to communicate with the USB device.

pip install pyusb

Loading (fw_load.py)
Dumping (fw_dump.py)

RAM Firmware Loader

fw_load.py loads firmware into the Cypress FX2 internal/external RAM via the standard 0xA0 vendor request built into the FX2 silicon boot ROM. This is the primary tool for firmware development: load, test, power-cycle to revert.

Subcommands

Subcommand	Purpose
`load`	Load a firmware file into FX2 RAM
`reset`	Halt and restart the FX2 CPU
`read`	Read and hex-dump FX2 RAM contents

load — Write Firmware to RAM

Halt the CPU — writes 0x01 to the CPUCS register at 0xE600
Write code segments into RAM in 64-byte chunks via vendor request 0xA0
Start the CPU — writes 0x00 to CPUCS, triggering USB re-enumeration

Supported file formats:

Extension	Format	Load Address
`.ihx`, `.hex`	Intel HEX	Addresses embedded in file
`.bix`, `.bin`	Raw binary	`0x0000` (start of internal RAM)

Options:

Flag	Description
`FILE`	Firmware file path (positional, required)
`--no-reset`	Load segments without halting/starting the CPU
`--wait SECONDS`	Wait for USB re-enumeration after load
`-v, --verbose`	Show per-chunk transfer progress
`--force`	Allow loading to devices with unknown VID/PID

Examples:

sudo python3 tools/fw_load.py load firmware/build/skywalker1.ihx --wait 3

sudo python3 tools/fw_load.py load firmware.bix -v --wait 5

sudo python3 tools/fw_load.py load firmware.ihx --no-reset

Typical output:

SkyWalker-1 RAM Firmware Loader
========================================

Firmware: firmware/build/skywalker1.ihx
  Segments:   3
  Total size: 3072 bytes
  Address:    0x0000 - 0x0BFF

Found SkyWalker-1: Bus 1 Addr 12 (VID 0x09C0 PID 0x0203)

[1/3] Halting CPU (CPUCS = 0x01)...
  CPU halted

[2/3] Loading 3 segment(s) into RAM...
  0x0000-0x03FF  (1024 bytes)
  0x0400-0x07FF  (1024 bytes)
  0x0800-0x0BFF  (1024 bytes)

  3072 bytes loaded

[3/3] Starting CPU (CPUCS = 0x00)...
  CPU released

  Firmware is running. The device will re-enumerate
  with new USB descriptors if the firmware does so.

reset — Restart the FX2 CPU

Halts and restarts the CPU without loading new code. Useful for triggering USB re-enumeration when the device is in a bad state.

sudo python3 tools/fw_load.py reset --wait 3

Flag	Description
`--wait SECONDS`	Wait for re-enumeration after reset
`--force`	Allow reset on unknown VID/PID

read — Hex-Dump FX2 RAM

Read memory contents from a running FX2. Useful for verifying loaded firmware or inspecting register state.

sudo python3 tools/fw_load.py read --addr 0x0000 --len 256

sudo python3 tools/fw_load.py read --addr 0xe600 --len 1

sudo python3 tools/fw_load.py read --addr 0x0000 --len 8192 -o ram_dump.bin

Flag	Description
`--addr ADDR`	Start address in hex (default: `0x0000`)
`--len LENGTH`	Bytes to read (default: `256`)
`-o, --output FILE`	Save raw bytes to file
`--force`	Allow read on unknown VID/PID

Device Detection

The loader searches for devices in this order:

SkyWalker-1 — VID 0x09C0, PID 0x0203
Bare Cypress FX2 — VID 0x04B4, PID 0x8613 (unprogrammed/blank EEPROM)

Use --force to override VID/PID checks for devices with non-standard descriptors.

Firmware Probe and Dump Tool

fw_dump.py queries device information, dumps FX2 RAM contents, and scans for undocumented vendor commands.

Options

Flag	Description
`--info`	Query and display device information
`--dump FILE`	Dump FX2 RAM to a binary file
`--scan`	Brute-force scan all vendor commands (0x00—0xFF)
`--start ADDR`	RAM dump start address (default: `0x0000`)
`--size SIZE`	RAM dump size in bytes (default: `0x2000` = 8 KB)
`--external`	Attempt to dump external RAM (64 KB)

Running with no flags defaults to --info --scan.

Device Info (—info)

Queries all known Genpix vendor commands and displays firmware version, build date, USB speed, serial number, and the 8PSK configuration status byte with decoded flags.

sudo python3 tools/fw_dump.py --info

=== Genpix SkyWalker-1 Device Info ===

  FW Version:  2.06.4 (0x020604)
  FW Build:    2007-07-13
  BCD Version: 0206
  Vendor:      Genpix
  Product:     SkyWalker-1
  USB Speed:   High (480Mbps)
  Serial:      00000000
  Config:      0x03
               [ ON] 8PSK Started
               [ ON] BCM4500 FW Loaded
               [off] Intersil LNB On
               [off] DVB Mode
               [off] 22kHz Tone
               [off] 18V Selected
               [off] DC Tuned
               [off] Armed (streaming)

Vendor Command Scan (—scan)

Sends vendor IN requests to every command index from 0x00 to 0xFF and reports which ones return data. Commands already documented in the reference are labeled [KNOWN]; unexpected responses are flagged [NEW!].

sudo python3 tools/fw_dump.py --scan

RAM Dump (—dump)

Reads FX2 internal RAM (8 KB at 0x0000—0x1FFF) or external RAM (up to 64 KB with --external) via the standard 0xA0 vendor request.

sudo python3 tools/fw_dump.py --dump internal_ram.bin

sudo python3 tools/fw_dump.py --dump external_ram.bin --external

sudo python3 tools/fw_dump.py --dump region.bin --start 0x1000 --size 0x800

The tool performs a quick analysis of the dump, reporting non-0xFF byte count and checking for the standard FX2 reset vector (LJMP at address 0x0000).

Kernel Driver Conflict

The Linux dvb_usb_gp8psk module auto-loads when the SkyWalker-1 enumerates on USB. It will race with these tools for device access.

Before using any tool, either blacklist the module or unload it:

sudo modprobe -r dvb_usb_gp8psk gp8psk_fe

echo -e "blacklist dvb_usb_gp8psk\nblacklist gp8psk_fe" | \
  sudo tee /etc/modprobe.d/blacklist-gp8psk.conf