[PLUG] I hosed my WRT54GL, need JTAG help

[Tim Wescott]

On Thu, September 3, 2009 10:56 am, Russell Senior wrote:
>>>>>> "m0gely" == m0gely  <m0gely at gmail.com> writes:
>
> m0gely> Well as I mentioned, the Linksys TFTP app indicates nothing no
> m0gely> router is there to communicate with. I successfully used this
> m0gely> app on the router when getting rid of the VXWorks OS. So I
> m0gely> know how that part works unless there are some additional
> m0gely> sneaky techniques.
>
> m0gely> As for the serial idea, are you referring to soldering on a
> m0gely> serial port?  That looks no less invasive than the JTAG
> m0gely> approach.
>
> If there is a header on the board, you don't need to solder.  I don't
> remember if the WRT54GL has populated the header or not.  That might
> go for the JTAG as well though.  From your description, it sounds like
> you do need JTAG.  If the CFE (the bootloader that Broadcom uses on
> the board) isn't coming up correctly, and isn't able to accept TFTP,
> then serial probably isn't going to help.  Serial could let you watch
> it fail though, which could be informative.
>
> As it happens, I just purchased a USB JTAG adapter (an Olimex
> ARM-USB-OCD from Sparkfun), but the software I am using with it
> (OpenOCD) does not support Broadcom MIPS boards (I got it for an
> ARM-based board, which is working ... yay!).
>
> I also have a parallel port "Wiggler" style adapter that someone
> loaned me, but I don't have any documentation for it and it isn't
> labelled with any identifying information that would let me find
> some.  I would loan it to you, but it isn't really mine to loan.
>
> There are lots of instructions online for making your own adapter.  If
> you've got a machine with a parallel port, some old cables and a
> soldering iron, you just need a few resistors and some elbow grease.

To some extent I can understand the fixation on not spending any money (I
have it too), but at this point I think if you went back in time, dressed
in your rattiest clothing, and stood outside of Powell's Technical Books
or Free Geek and begged passers-by for spare change for a JTAG adapter
you'd find that you'd get enough to buy one from Olimex for the time
you've spent digging for information here.

-- 
Tim Wescott
Control systems and communications consulting
http://www.wescottdesign.com

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