DirtyJTAG

DirtyJTAG is a JTAG adapter firmware for $2 ST-Link clones and generic STM32 development boards ("blue pill"/"black pill" STM32F101 and STM32F103 based ARM boards). The DirtyJTAG project was meant to be an alternative to the obsolete (but cheap) LPT Wiggler cables, and other expensive USB JTAG probes.

DirtyJTAG is dirty and dirt cheap, but is not fast nor a perfect implementation of the JTAG protocol. Yet it is around 1k lines of code, making it easily understandable and hackable.

If you prefer OpenOCD to UrJTAG, I suggest using Zoobab's fork of Versaloon firmware, which is available on his GitHub repository.

Build your DirtyJTAG adapter

Bluepill	ST-Link v2 clone (dongle)	ST-Link v2 clone (white case)	"Baite" ST-Link v2 clone

Instructions	Instructions	Instructions	Instructions

Olimex STM32-H103	Raspberry Pi Pico

Instructions	External project

Software compatible with DirtyJTAG

UrJTAG: support added in 2017.10
openFPGAloader: support added in v0.1
flashrom: support added in 1.3
OpenOCD: patch in review

USB VID and PID

All DirtyJTAG-flashed devices appear with the following USB VID=0x1209/PID=0xC0CA (which belongs to "InterBiometrics") :

$ lsusb
[...]
Bus 002 Device 003: ID 1209:c0ca InterBiometrics

The PID was obtained through http://pid.codes, which is a registry of USB PID codes for open source hardware projects. More infos: http://pid.codes/1209/C0CA/

dmesg also give some output where you can see the manufacturer field as "Jean THOMAS":

$ dmesg
[...]
[55444.904830] usb 1-3: new full-speed USB device number 12 using xhci_hcd
[55445.033099] usb 1-3: New USB device found, idVendor=1209, idProduct=c0ca, bcdDevice= 1.10
[55445.033105] usb 1-3: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[55445.033108] usb 1-3: Product: DirtyJTAG
[55445.033111] usb 1-3: Manufacturer: Jean THOMAS
[55445.033114] usb 1-3: SerialNumber: 55FF6E064980515631491787

Older versions of DirtyJTAG reported "DirtyJTAG" as the manufacturer, this bug has since been fixed.