[PLUG] I hosed my WRT54GL, need JTAG help

Russell Senior russell at personaltelco.net
Thu Sep 3 17:56:14 UTC 2009


>>>>> "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.


-- 
Russell Senior, President
russell at personaltelco.net



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