Help. ASUS RT-AC68u bricked - JTAG help needed

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MichaelB

New Around Here
Hi,
I have a Asus RT-AC68u that I accidentally bricked doing an upgrade to the latest merlin software.
I was having trouble with it not producing a decent output signal, and I'm pretty sure I corrupted the CFE
probably in impatience when it was reloading.

In any case, I get nothing on the Serial port, and of course have tried TFTP and recovery mode using the reset switch during boot. I have a solid USB 2.o lite and if I plug an ethernet cable in port 1 it flashes, but no response monitoring with wireshark and attempting a tftp. No ping response at all.

I was able to hook up a JTAG connection using a Raspberry Pi, and can see the CPU on a scan_chain using
openocd but it looks like openocd does not have good support for the BCM4708 cpus. I've tried to make some adjustments for it, but if I try to do a flash erase I get an error and the connection resets and I start over.
I can see the cpu on an autoprobe as well.

Is there a resource with a JTAG TCL command set or scripts that supports the BCM4708 cpu target and this router? If there is someone here that can kindly provide some guidance I would sure appreciate some direction.
Hate to be stuck at the point when I can talk via the JTAG interface.

Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
Open On-Chip Debugger
> scan_chain
TapName Enabled IdCode Expected IrLen IrCap IrMask
-- ------------------- -------- ---------- ---------- ----- ----- ------
0 auto0.tap Y 0x502bf17f 0x00000000 3 0x01 0x03

>

Thanks in advance.

Michael
 

ZeLbeT

New Around Here
Hello. I have bricked exact router as yours. Could you share info, how to connect JTAG to board?
 

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