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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^...
user3547018's user avatar
4 votes
0 answers
27 views

JTAG Version 2.0 or 2.1

I need to identify which device has JTAG Version 2.1 for TI TMS320DM8168CCYG4 (Digital Media Processor). What socket is recommended?
Charlie Polidoro's user avatar
4 votes
1 answer
223 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 ...
Rulon Rock's user avatar
3 votes
0 answers
61 views

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 ...
Raghav Varmani's user avatar
2 votes
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Greenpacket OH-735 onboard header

I got myself a Greenpacket OH-735 LTE outdoor unit. On the outside it has a SIM slot and an ethernet interface. Access to the web interface is pretty restricted, not much to set and it is branded with ...
James's user avatar
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2 votes
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151 views

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 ...
Mounish Periasamy's user avatar
2 votes
0 answers
341 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, ...
user2296435's user avatar
2 votes
0 answers
559 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) ...
alperc's user avatar
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2 votes
0 answers
187 views

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 ...
menotyou's user avatar
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1 vote
0 answers
49 views

Finding JTAG/UART Connections on smart doorbell

Trying to dump firmware of this device. I can't find the UART/JTAG connections. I've searched over it for awhile now; I feel like I must just be missing something.
Eric's user avatar
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1 vote
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Reading/writing flash ROM connected to OMAP L138 without JTAG

I have a product that uses an OMAP L138 with a flash rom. There are a couple different models of this product available, but they all share the same hardware with the only difference being the ...
Patrick's user avatar
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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 ...
Baliio's user avatar
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1 vote
0 answers
100 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 ...
batflaps's user avatar
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1 vote
0 answers
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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 ...
batflaps's user avatar
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1 vote
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110 views

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 ...
firsttry's user avatar
1 vote
0 answers
1k 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 ...
poolshark021's user avatar
1 vote
0 answers
333 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 ...
doe0731's user avatar
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0 answers
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Cloning full content of a pic24fj128gc010 chip (Flash + RAM)

I have some hardware that uses a PIC24fj128gc010 microcontroller. This microcontroller lives on a pluggable board that is plugged in on a main board. This detachable board has the microcontroller with ...
user45316's user avatar
0 votes
1 answer
97 views

Microchip ATSAME70Q21-CN unable to connect with JTAG or SWD

First time delving into hardware reverse engineering and can't seem to connect using JTAG nor SWD. I found two identical devices that I'm trying to understand how they work and see if I can extract ...
kumaichi's user avatar
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75 views

embedded Linux, UART & JTAG disabled, how to access system?

So i have this device running embedded Linux, UART and JTAG interfaces are disabled by software. The device creates a WiFi hotspot and i know the password. By entering the devices IP adress i can ...
AB.M's user avatar
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