Team Cygnos integrates JTAG hack into Cygnos360 v2

October 13th, 2009, 04:29 Posted By: wraggster

News via http://www.xboxscene.com/

The last couple of weeks have been very turbulent for all Xbox360 lovers. We have seen some very good developments towards homebrew and better linux.

We had fought with delays caused by the manufacturing and sourcing process which we finally solved. Now, Cygnos360 V2 is on stock at several shops and on the way to others. Production is still slow but ramping up and we are shortening delivery times.

We did however not spend the time waiting doing nothing. We have used the time to significantly improve the functionality and usability of Cygnos360 V2.

* Most interesting new features are:
-Integration of the JTAG hack into our firmware so that we can play the role of the microcontroller doing the JTAG inject. This is running and tested on xenon and falcon mainboards. The other versions will follow via software updates. No taking apart or re-wiring needed. (please note that we cannot (yet) read and program the 256 & 512 Mb jaspers, 16Mb Jaspers are fine)
-The Cygnos360 V2 USB board now has a vertical USB connector. That way it is much easier and cleaner to install in your Xbox360.


This is a photo of the production version of Cygnos360 V2
-We have added the possibility to communicate from "Xell" to Cygnos360 V2, for example to switch kernel via software command. (hotswap)
-We have added the functionality to enable switching between kernels having different SMC versions. It is not necessary to unplug the console for kernel switching, which is the case on current homebrew nand switchers and XD card solutions.
-We have added a back-channel to the Cygnos360 V2 that enables developers to talk back from applications running on the 360 to Cygnos. This way it is possible for example to send data from within the 360 to the PC via Cygnos360 V2. (e.g. temperatures, CPU/DVD key, or other nice stuff)

* Firmware and Toolbox
A flaw in our firmware has been fixed that caused the JTAG hack to work only once every power cycle. The JTAG hack has so far been tested on Xenon and Falcon. Opus is very likely to work as well. We appreciate, if anyone could test this on a Zephyr. Please report any errors!
The new toolbox in conjunction with the firmware will display serial output from XeLL, Linux, etc. in the console window. Here is a screenshot of the new toolbox:


Output coming from the Xbox 360 is colored yellow in order to distinguish it from toolbox messages (green). Since XeLL outputs the fuse settings via serial port, there's now a very convenient way to save these to a file.
Download the new firmware and toolbox from here

* XeLL
Since our microcontroller cannot handle serial communication at 115200 baud, we had to make a minor modification to XeLL. The modification will set the baud rate register of the Xbox 360 to 38400 baud, 8 data bits, no parity and one stop bit. This implies that you have to build a custom JTAG hack image for Cygnos360 V2 with our modified XeLL. You can download the XeLL binaries and sources from here.

* imgbuild
The free60 imgbuild tool does by default not generate a full image as required by our toolbox. We therefore modified the build script accordingly. You can download the whole package from here.
Building your own image under Windows requires the installation of a Python interpreter. The simplest way is to download and install the Cygwin base system along with the "python" and "python-crypto" packages from here[cygwin.com].
Our modified imgbuild tool does not require a full binutils/gcc toolchain to generate an image. We included a precompiled payload binary instead. The SMC config block is taken from a dump of your Xbox 360. A typical command to generate and image would look like this:
python build.py dump.bin CBxxxx.bin CDxxxx.bin xboxupd.bin smc_hacked.bin xell-1f.bin
CBxxxx.bin and CDxxxx.bin are console (Xenon, Zephyr, Falcon, Opus, Jasper) specific, as well as smc_hacked.bin. Please use the xell-1f.bin from our XeLL package.

* Manual
For all interested for more info, check out the installation manual it contains a lot of info:

Happy Hacking!
Team Cygnos

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