Unlocking secret ThinkPad functionality for emulating USB devices
https://xairy.io/articles/thinkpad-xdci [xairy.io]
2024-03-11 07:42
This is the story of how I figured out a way to turn my ThinkPad X1 Carbon 6th Gen laptop into a programmable USB device by enabling the xDCI controller.
As a result, the laptop can now be used to emulate arbitrary USB devices such as keyboards or storage drives. Or to fuzz USB hosts with the help of Raw Gadget and syzkaller. Or to even run Facedancer with the help of the Raw Gadget–based backend. And do all this without any external hardware.
The journey of enabling xDCI included fiddling with Linux kernel drivers, xHCI, DWC3, ACPI, BIOS/UEFI, Boot Guard, TPM, NVRAM, PCH, PMC, PSF, IOSF, and P2SB, and making a custom USB cable
source: trivium