JTAG-ing - Anyone able to advise?

"Andy Burns" wrote in message
o.uk...

Andy Burns wrote:

Java Jive wrote:

http://www.diygadget.com/tiao-usb-mu...2c-serial.html

Looks like a handy card to have around, especially as I've mislaid my
USB to TTL level RS232 dongle, there is a cheaper "lite" version of the
TUMPA

Just to mention, I id order one of of the tumpa-lite cards, and it
arrived today, I've still got to solder on its connector pins, then I'll
have a play with JTAGing an old router ... could be the sort of card I
hardly ever use, but cheap enough to have around in case it ever saves
the day ...
+++++++++++
If you come across a good introduction and example for what JTAGing is, what
you can do with it and how, please share. I know vaguely what it is but
have yet to get well enough into it to use it in anger and most guides are
written by people who know what they're doing, for people who know what
they're doing.

Paul DS

On 08/10/14 08:12, Paul D Smith wrote:

+++++++++++
If you come across a good introduction and example for what JTAGing is,
what you can do with it and how, please share. I know vaguely what it
is but have yet to get well enough into it to use it in anger and most
guides are written by people who know what they're doing, for people who
know what they're doing.

Paul DS

JTAG is a low level interface to integrated circuits.

It can be used for PCB testing and for low level access to ARM
processors and FPGA devices. It can probably be used for other things as
well.

There is some high level explanation
in:-http://en.wikipedia.org/wiki/Joint_Test_Action_Group#Storing_firmware

For an ARM processor you can use the CoreSight software together with
the JTAG port to debug software and even integrated circuits.

JTAG is used to download the FPGA configuration data. This data makes
the FPGA into the silicon that you have designed.

There is OpenJTAG which is free software to communicate via a JTAG port.
http://en.wikipedia.org/wiki/Open_JTAG

There is also Open ocd which is intended for debugging integrated
circuits (and other things).
http://openocd.sourceforge.net/

If the hardware that you are trying to fix contains an ARM then you
should have a look at the CoreSight documentation.

One basic instruction is IDCODE. That gives you the integrated circuits
unique identifier. From there on you know exactly what integrated
circuit you are dealing with.

You can read/write to integrated circuit registers. This can be risky
you need to know what you are doing.

You can write to firmware/flash as well.

I use this in a very low level so it will not help you much.

This is the best I can think of at the moment. Good luck. Andy

Dave Farrance wrote:

Andy Burns wrote:

Java Jive wrote:

For example (quite expensive) ...
http://www.diygadget.com/tiao-usb-mu...2c-serial.html

Looks like a handy card to have around, especially as I've mislaid my
USB to TTL level RS232 dongle, there is a cheaper "lite" version of the
TUMPA

http://vgshop.ecrater.co.uk/p/157748...otocol-adapter

Mind you, USB TTL cables cost £1 if you don't mind waiting the few weeks
for one to turn up from China.

I'm returning to this old thread to note that Scottish firm FTDI released
a change through Windows Update that deliberately bricks these Chinese
USB/serial cables and adaptors. Not just so that Windows refuses to work
with them, but renders them inoperable so that they can't then be used
with Linux either:

http://tinyurl.com/k3w2ztz which links to:

http://arstechnica.com/information-t...dware-hackers/

On 25/10/2014 06:46, Dave Farrance wrote:

I'm returning to this old thread to note that Scottish firm FTDI released
a change through Windows Update that deliberately bricks these Chinese
USB/serial cables and adaptors. Not just so that Windows refuses to work
with them, but renders them inoperable so that they can't then be used
with Linux either:

http://tinyurl.com/k3w2ztz which links to:

http://arstechnica.com/information-t...dware-hackers/


As it is a Scottish company, surely they are committing an offence under
the Misuse of Computers Act?

Jim

Dave Farrance wrote:

I'm returning to this old thread to note that Scottish firm FTDI released
a change through Windows Update that deliberately bricks these Chinese
USB/serial cables and adaptors.

Yes, I heard about that (but didn't check full details yet) is it
bricking boards with fake chips, or boards with genuine chips that
"borrow" the vendor/device/subsystem IDs of genuine boards? Maybe the
latter would be impossible to tell ...

Indy Jess John wrote:

On 25/10/2014 06:46, Dave Farrance wrote:

Scottish firm FTDI released a change through Windows Update that
deliberately bricks these Chinese USB/serial cables and adaptors.
Not just so that Windows refuses to work with them, but renders
them inoperable so that they can't then be used with Linux either:
http://tinyurl.com/k3w2ztz

As it is a Scottish company, surely they are committing an offence under
the Misuse of Computers Act?

It seems to me that they're on pretty shaky ground. Chinese fakers will
not only duplicate the functionality of chips but put fake manufacturer
markings on them, which is definitely not on, but such cloned chips could
potentially find their way into life-protecting equipment. And although
the USB vendor-ID that FTDI re-wrote is assigned to their company, that is
not legally protected in a way that gives them the right to remove it.

I understand that the re-writing of the VID was possible because the
Chinese clones use a programmable microcontroller to emulate the FTDI
chip. FTDI have now backed down it seems, the change has been removed
from Windows Update, and they've issued a utility which reverses the
change to the cloned chips, but they're still determined to make their
drivers incompatible with the clones.

http://www.theregister.co.uk/2014/10...iver_response/

I've looked at the cables and adaptors that I use, and fortunately they've
either got very old FTDI chips, predating the influx of clones, or they've
got Silicon Labs or Prolific Technology chips instead. It does seem that
the cheapest Chinese serial adaptors and cables don't use FTDI clones.

On Sat, 25 Oct 2014 09:28:17 +0100, Dave Farrance
wrote:


Scottish firm FTDI released a change through Windows Update that
deliberately bricks these Chinese USB/serial cables and adaptors.
Not just so that Windows refuses to work with them, but renders
them inoperable so that they can't then be used with Linux either:
http://tinyurl.com/k3w2ztz

As it is a Scottish company, surely they are committing an offence under
the Misuse of Computers Act?

It seems to me that they're on pretty shaky ground. Chinese fakers will
not only duplicate the functionality of chips but put fake manufacturer
markings on them, which is definitely not on, but such cloned chips could
potentially find their way into life-protecting equipment. And although
the USB vendor-ID that FTDI re-wrote is assigned to their company, that is
not legally protected in a way that gives them the right to remove it.

I understand that the re-writing of the VID was possible because the
Chinese clones use a programmable microcontroller to emulate the FTDI
chip. FTDI have now backed down it seems, the change has been removed
from Windows Update, and they've issued a utility which reverses the
change to the cloned chips, but they're still determined to make their
drivers incompatible with the clones.

It seems they're doing more than just making their drivers
incompatible with the clone hardware, but effectively vandalising the
clone hardware to make it incompatible with anything. Since the clones
do appear to be actual fakes, right down to the markings, rather than
reverse-engineered equivalents, the company may have a genuine legal
grievance, but it should be pursued through proper legal process like
anything else. What they are doing is more like vigilante action, and
they may live to regret it far more than they might regret losing a
few sales to the Chinese. Your point about the cloned chips being used
in life-protecting equipment is an extremelly worrying one. If this
software war doesn't stop now, it can only be a matter of time before
somebody dies as a result of it.

Rod.

In message , Roderick
Stewart writes
On Sat, 25 Oct 2014 09:28:17 +0100, Dave Farrance
wrote:


Scottish firm FTDI released a change through Windows Update that
deliberately bricks these Chinese USB/serial cables and adaptors.
Not just so that Windows refuses to work with them, but renders
them inoperable so that they can't then be used with Linux either:
http://tinyurl.com/k3w2ztz

As it is a Scottish company, surely they are committing an offence under
the Misuse of Computers Act?

It seems to me that they're on pretty shaky ground. Chinese fakers will
not only duplicate the functionality of chips but put fake manufacturer
markings on them, which is definitely not on, but such cloned chips could
potentially find their way into life-protecting equipment. And although
the USB vendor-ID that FTDI re-wrote is assigned to their company, that is
not legally protected in a way that gives them the right to remove it.

I understand that the re-writing of the VID was possible because the
Chinese clones use a programmable microcontroller to emulate the FTDI
chip. FTDI have now backed down it seems, the change has been removed
from Windows Update, and they've issued a utility which reverses the
change to the cloned chips, but they're still determined to make their
drivers incompatible with the clones.

It seems they're doing more than just making their drivers
incompatible with the clone hardware, but effectively vandalising the
clone hardware to make it incompatible with anything. Since the clones
do appear to be actual fakes, right down to the markings, rather than
reverse-engineered equivalents, the company may have a genuine legal
grievance, but it should be pursued through proper legal process like
anything else. What they are doing is more like vigilante action, and
they may live to regret it far more than they might regret losing a
few sales to the Chinese. Your point about the cloned chips being used
in life-protecting equipment is an extremelly worrying one. If this
software war doesn't stop now, it can only be a matter of time before
somebody dies as a result of it.

Only last week, UK dentists were being warned to beware of buying cloned
dental equipment, as the consequences could be very serious for their
patients. It was mentioned that 'CE' might simply mean 'China Export'.
--
Ian

On Sat, 25 Oct 2014 09:03:27 +0100, Andy Burns wrote:

Dave Farrance wrote:

I'm returning to this old thread to note that Scottish firm FTDI
released a change through Windows Update that deliberately bricks these
Chinese USB/serial cables and adaptors.

Yes, I heard about that (but didn't check full details yet) is it
bricking boards with fake chips, or boards with genuine chips that
"borrow" the vendor/device/subsystem IDs of genuine boards? Maybe the
latter would be impossible to tell ...

Its chips 'borrowing' the IDs of genuine FTDI chips. Nothing to do with
whatever board whose mfr saw fit to buy cheap Chinese FTDI chip clones. I
believe it only affects USB-serial adapter chips.



--
[email protected] | Martin Gregorie
gregorie. | Essex, UK
org |

Martin Gregorie wrote:

Its chips 'borrowing' the IDs of genuine FTDI chips. Nothing to do with
whatever board whose mfr saw fit to buy cheap Chinese FTDI chip clones. I
believe it only affects USB-serial adapter chips.

yeah, but what flavour of serial? Only RS23, or the other chips that can
do I2C/JTAG/GOIP as well?

I've got a couple of USB-RS232-9pin cables (genuine direct from FTDI)
and one USB-TTL-level with flying leads which is likely (based on
price) to be fake, dunno where it is at moment though.

Also have the TUMPA-lite as mentioned up-thread which has an FT232H, it
is printed rather than laser etched, which I understand is a sign of
being fake, but I don't know if the legit drivers have that chip in its
sights ...