Author Topic: What's a modern JTAG solution for 'debricking' wifi routers?  (Read 294 times)

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Offline cdev

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What's a modern JTAG solution for 'debricking' wifi routers?
« on: February 06, 2018, 03:02:15 PM »
Basically, I want to convert my Linksys WRT54GL to a GS or similar by upgrading the flash and RAM chips.

This will likely require JTAG.

'Back in the day" the preferred tool was a JTAG cable made using a PC parallel port. However my current PC doesnt have a parralel port and the only PC I have that does is not working at the moment, its not really able to be used for that.

Afterward the router needs to be told about the extra memory.

Many people have told me just to forget about it. They are so old, etc.

But I cant just throw it away, its an old friend.

With two new chips it can run current SW.

So, according to the open OCD web page, the traditional old JTAG cable was the wiggler.

What would be a good way to replicate its functionality now?

Its likely very simple, what I need to do, at the beginning, but since its fairly straightforward I am going to add the JTAG header.

I guess what I am asking about is cross-compatibility. Will the newer JTAG cables work.

I think I can make my logic analyzer into a USB-Blaster compatible JTAG cable.

Can I use that to debug a Broadcom-chip based Linksys router?
« Last Edit: February 07, 2018, 01:42:45 PM by cdev »
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Offline ChuckDarwin

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Re: What's a modern JTAG solution for 'debricking' wifi routers?
« Reply #1 on: February 09, 2018, 10:28:43 AM »
If you just want to load the CFE/Flash and see if it comes to life by watching the serial console, rather than have a solid debugging session, you can bit bang the JTAG with a raspberry pi.  This was/is the low-cost recovery method for a bricked router.  If you search on bricked wrt54xx you should find some pre-built tool sets to load the device you want.



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