Questions tagged [jtag]

JTAG, short for Joint Test Action Group, is a method used for boundary scanning. Possibly applications are hardware testing/debugging and firmware flashing, including debricking of hardware which ended up in a defunct state.

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JTAG Dumped Flash is scrambled

I dumped the flash memory of an old ARM9 Chip running VxWorks using the SEGGER J-Link and the savebin command from J-Link Commander. Here is an example of a line of HTML stored on memory. <!DOC^...
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Help required to figure out the JTAG or UART pins

I have an old CDMA dongle lying around, so I thought to try to reverse engineer them, but am unable to figure out the UART or JTAG pins, I have attached a photo of the probable pins, can anyone help ...
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77 views

Dump Headunit Software

I am a computer engineering senior and have a few quick questions i couldn't find any hits about online. I know just enough to get myself into trouble. Note: I have no specialized tools just a DMM and ...
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121 views

What is an "mpi register base"?

For the past few months, I have been using my spare time reverse engineering a set top box that will not be named. I am trying to run a media server or use it as a debian desktop. It is rocking a ...
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MSP430 JTAG FUSE

I'm using MSP430 micro controller which support physical fuse for jtag. The problem is I have blown the physical fuse so I can't interact with the controller, is there any way that I can interact with ...
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221 views

Help identify missing component for jtag connection

I found JTAG header for ARM (OMAP3x). It's a Cortex 10-pin 0.05" JTAG/SWD Connector. (See here) I think it's JTAG because PIN#3 and 5 are on GND and it's close of CPU When I follow the wires, TCK, ...
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432 views

Solve problem with debugging Linksys-wrt54gl with JTAG using BusPirate programmer

I am getting this output when I am issuing this command: $ sudo openocd -f board/MyBuspirate.cfg -f board/linksys-wrt54gl.cfg Open On-Chip Debugger 0.10.0+dev-00092-g77189db (2017-02-25-13:44) ...
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JTAG finding BS registers for IC's pins

On the internet, it always shows that each pin of the IC has its own Boundary Scan register (the yellow boxes) But looking at BSDL files there are actually more BS registers than pins. So for the ...
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WRT54GL firmware extraction via JTAG with OpenOCD and Raspberry Pi as interface. Can not dump because the device is not halted

Good day! Sorry to come up with something very old. Since I am currently teaching myself hardware hacking, I wanted to use my old router for this. I soldered pins to the JTAG interface and connected ...
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53 views

cheap BGA x-ray machine?

I want to look under a BGA chip and map JTAG pins to traces where I can attach a JTAGulator. Is there some version of a BGA x-ray that isn't thousands of $'s? Here's a picture of the BGA's. Would it ...
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58 views

ARM 20-pin JTAG header?

I'm trying to find the JTAG header for an Intel X Scale (ArmV5) PXA270 board. I found and populated a 20-pin header: but JTAGulator doesn't think it has a valid combination of TDI/TDO/TMS/TCK on ...
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Finding the function of test points on a router

I have a BCM3383 based cable router here where I ultimately want to dump the firmware. I have serial access to the broadcom bootloader and the linux console. Login for linux is unkown and telnet does ...
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886 views

Trying to dump firmware from embedded flash

I have an Infineon XC161CJ-16F SoC and Micron/ST M29W320EB parallel nor flash memory that I am trying to dump the firmware from but I'm not sure how to proceed. I found JTAG pads that I soldered pins ...
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293 views

OpenOCD, Buspirate JTAG reads fail after short time

I have a board that I'm reversing - and attempting to dump the image out of the NAND flash. Board has a SAMSUNG s3c2440 SOC CPU, and there's a SAMSUNG k9f1g08u0d 128 MB NAND flash device. I'm using ...
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How can I identify JTAG in this case and utilize it?

I'm developer and I somehow tried today to reverse engineer and take apart a hardware, just after learning that some devices have hardware debugging. First thing to try to know in my understanding of ...
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Unknown but suspiciously aligned test pads

I am currently working on an Epson printer main board that exposes 5 aligned test pads (see image). The board also exposes a row of 4 pins that turned out to be UART. Now I am wondering if these could ...
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43 views

How to clone flash memory over JTAG connection?

I am a computer software programmer. I am trying to deal with some basic electronic concepts. I have an onboard TMS320F243 which needs to be cloned. I currently have the following setup... I have ...