OpenWrt Forum Archive

Topic: plz help to identify JTAG port on RV042

The content of this topic has been archived on 12 Apr 2018. There are no obvious gaps in this topic, but there may still be some posts missing at the end.

Hello,

I've recently got a new Linksys RV042 that I intended to use for my office, but the stock firmware from Linksys is so limiting I could not use it.  I've decided instead to install OpenWRT (I realize the RV042 is not yet supported hardware, but it does use the IXP425 platform which seems well supported).  I used "jungo-image.py" script to create an export of the old firmware image, so I can begin to experiment with OpenWRT/DDwrt/OpenIXP, etc...

My first attempt was to upload the the OpenWRT image for the IXP4xx series "http://downloads.openwrt.org/kamikaze/8 … 4xx-zImage".  I did so using the Jungo script, and I bricked the unit good. smile 

So now I have a dead RV042 that I must recover.   wink  The trick with TFTP during bootup did not work like on the WRT54G, since the unit won't power up the ethernet ports anymore. wink  Also, the factory reset button on the back simply does nothing. It seems like my final option is to use JTAG, which I am comfortable with and have used before (and have done plenty of soldering).

But, I'd like some feedback on which JTAG cable I should try using, and suggestions as to which port on the board is likely the JTAG interface wink

Here is an image of the RV042 circuit board, it's not mine, but looks identical:

http://www.mobiltex.com/~tdacosta/images/rv042a-new.jpg

You can see at the top there is a 10 pin port named COM1, and a 20 pin port labeled JP2.  COM1 is obviously a serial port, which leaves JP2 as the only viable JTAG interface. I believe it's this one:

http://microcontrollershop.com/Images/a … nector.gif

Does this seem right?  And if so, which type of JTAG interface cable should I try using on this device?   (http://oldwiki.openwrt.org/OpenWrtDocs% … Cable.html)

I look forward to any feedback. Thanks for your time.

Oh, I found this page on the openWRT site which speculates that JP2 is the JTAG port:

http://oldwiki.openwrt.org/OpenWrtDocs% … ardware%29

I'll try adding the necessary headers to the circuit board and see if I can restore the original image through JTAG.

Have a look onto the WRV54G page at
http://oldwiki.openwrt.org/OpenWrtDocs( … RV54G.html.
This device is IXP425 based, too. The page describes the layout of the standard ARM JTAG head used there and from your picture I guess that pins 4,6,8,..20 and 11 are connected to GND, which would match that page. Pin2 seems to be at 3.3V.

Recovery procedure on RV042 firmware:
1 download firmware http://www.cisco.com/en/US/prod/routers … rmware.zip
2 disconnect the power cable on router
3 press and hold reset button, apply the power connector and waiting one minute, release reset button
4 settings network on your computer:
-IP:192.168.1.2
-Mask:255.255.255.0
-Gateway:192.168.1.1
5 connect network cable to the router and open web browser http://192.168.1.1
6 select the firmware and upgrade
7 wait few minute until upgrade is completely
8 ready

The recovery procedure stated by s_dorin won't work as the raw image burned by nopoles clobbered the bootloader. Only solution is to reinstall the original image via JTAG.

It is never a good idea to install firmware on unsupported boards!

Hello,

While playing with console I bricked RV042, anyone have an idea how to recover after this set of commands:

SME boot> flash_layout
Flash layout:
Section 00 Type BOOT Range 0x00000000-0x000F0000 MaxSize 0x000F0000
No more information.

Section 01 Type BOOTCONF Range 0x000F0000-0x00100000 MaxSize 0x0000FEEC
Uninitialized.

Section 02 Type IMAGE Range 0x00100000-0x00640000 MaxSize 0x0053FEEC
Size 0x004F1900 Name 'Downloaded at: Wed Jan 1 00:03:03 2003' Version '1.3.9'
Checksum 0x285A960A Counter 0x00002998 Start Offset 0x00000000

Section 03 Type CONF Range 0x00640000-0x007C0000 MaxSize 0x0017FEEC
Size 0x00004AA3 Name 'rg_conf'
Checksum 0x002473EE Counter 0x000043C2 Start Offset 0x00000000

Section 04 Type FACTORY Range 0x007C0000-0x007E0000 MaxSize 0x0001FEECSize 0x0000017C Name 'Image downloaded from: tftp://192.168.1.101/RV042/rg_factory3'
Checksum 0x00006B03 Counter 0x0000001C Start Offset 0x00000000

SME boot> flash_erase -d 03
Returned 0

SME boot> flash_commit

Returned 0

SME boot> restore_default -dopen DHCP Server for dev ixp0

Restore default completed successfully.

Returned 0

SME boot> reboot
Going to reboot!
Restarting system.

and after this it's not booting...

br.
--
Wbm.

The discussion might have continued from here.