Using Arduino as a JTAG interface for flashing/debugging various devices ...

Hi all,

I'm actually gathering informations about designing some code for interfacing an Arduino to whatever JTAG interface capable. I'm facing a lack of informations which is not helping me at all.

I started these researches because a friend of mine gave me a Samsung Galaxy 3 which is perfectly bricked (during a flash where the bootloader was written, câble fell off ...). Actually the phone doesn't powers on at all (it even doesn't enter in the DOWNLOAD MODE when pressing the combination of keys). Moreover, i tried a solution where a resistor has to be put between two pins of the micro-USB connector -> nothing more !

So actually this phone is DEAD, and, lucky me, i can try whatever i want/need/can on it !

I know where the JTAG connector is, and i know the pinout. I have the connector to connect something on it (a breadboard for example).

Now, let's talk about what i'm facing ... I need some documentations about JTAG protocol. How to communicate between devices. I especially need some kind of informations about JTAG protocol used on the CPU of the Samsung Galaxy 3 (Samsung S5P6422 // appears that datasheet is very hard to find !)

If someone already managed to build some JTAG-like interface based on the Arduino, it would be really great.

By the way, i have some skills on software programming under Windows .NET technologies, so, writting a small piece of code for communicating with the [Arduino-JTAG-Interface] would be easy to do !

Thanks !

Hi I haven’t bought myself an Arduino yet because I am still trying to figure out which one I need to buy and the relevant other bits to be able to jtag into my phone an I727R S2 which is also bricked. I found this page regarding jtag commands maybe it will help you a bit. On my end though can you tell me which bits and bats I need to jtag into my phone?

http://urjtag.org/book/_jtag_commands.html

I hit previous page on that link a few times to get to the supported devices list and these two arduino boards were listed.

Atmel ATmega128 (partial support)

Atmel AT32AP7000 (partial support)

I will keep searching and anything that I find that may help us I will post here.