In the DMA cheating community, the concept of a “Whitelist Firmware” is often sold as the ultimate solution. The pitch is simple: “We flashed your FPGA to look exactly like an Intel AX210 WiFi card. The anti-cheat trusts Intel WiFi cards, so you are safe.”

This logic is flawed. It relies on a superficial understanding of how operating systems and kernel drivers interact with hardware. Today, we dissect why the “Whitelist” is a myth.

The “Skin-Deep” Disguise

When you flash a firmware that copies the Vendor ID (VID) and Device ID (DID) of a legitimate device, you are essentially putting on a mask.

• The OS sees: “Intel WiFi Card.”
• The Anti-Cheat sees: “Intel WiFi Card.”

So far, so good. But what happens next is the problem.

1. The Driver Binding Problem

If you pretend to be a WiFi card, Windows will helpfully load the actual Netwtw10.sys (Intel WiFi Driver) for your device.

• The Crash: The real driver will attempt to send initialization commands to your FPGA. Since your FPGA is just a dumb memory reader and not a complex radio frequency transceiver, it won’t reply correctly.
• The Error Code: The driver fails to start (Code 10 or Code 43 in Device Manager).
• The Flag: Anti-cheats monitor for devices that claim to be standard hardware but are failing to start their drivers. A “broken” WiFi card is suspicious.

2. The BAR Sizing Mismatch

Real devices have complex memory requirements (BARs - Base Address Registers) mapped in specific ways.

• FPGA Limitations: Many cheat firmware implementations use standard 4KB or 1MB BARs because it’s easy.
• The Check: If you claim to be an NVIDIA GPU but you only request 4KB of memory, the math doesn’t check out. It’s an immediate red flag.

3. Capability Structs and DSN

PCIe devices verify their identity through more than just IDs. They have “Capability Linked Lists” and “Device Serial Numbers” (DSN).

• Lazy Cloning: Cheap firmware providers often copy the IDs but leave the Capability List as default Xilinx.
• Result: It’s like a person wearing a police uniform but carrying a water gun. The discrepancy reveals the fraud.

The “Shadow Device” Solution (and its limits)

To fix the driver problem, some advanced firmware developers use a technique called “Shadowing” or “Passthrough.” They disable the legitimate device on the motherboard but keep it physically powered, then make the FPGA mimic its responses.

However, modern anti-cheats (like Vanguard) perform Integrity Checks:

1. Memory Writes: They write a random value to a specific register on the “WiFi Card” and expect it to persist or behave in a known way. An FPGA mimicking a device simply ignores this or responds statically.
2. Timing Analysis: The response time of an FPGA over a PCIe riser is microscopically different from a PCH-integrated device.

Conclusion

There is no such thing as a passive “Whitelist.” You cannot simply “be” a legitimate device; you must act like one, responding to driver interrupts, managing power states, and handling proprietary commands.

Unless you are simulating the full silicon logic of an Intel Network Controller (which is impossibly complex for a simple cheat firmware), “Whitelist Spoofing” is just a game of probability—hoping the anti-cheat doesn’t check too deep today.