How to Install Third Party Firmware on NETGEAR WNR3500Lv2 With A Serial Cable on Linux

Depending on your situation with your WNR3500Lv2, it may be helpful (or necessary) to install third party firmware using a direct connection, utilizing a serial cable. This tutorial may also be used to recover your router from a bad flash, or to install a new firmware if you are somehow unable to log in over the network. Here's what you'll need:

  • A NETGEAR WNR3500Lv2
  • A Torx screwdriver, which is used to open the case of the router
  • A USB-TTL cable or compatible serial cable
  • A Linux machine with the minicom terminal program installed

STEP 1:

Run minicom from Linux machine. Configure the baud rate 115200 8N1. Connect one end of serial cable to your router and another end to your PC.

The pin configuration of router serial console pins are explained in the following two pictures (Fig.10 & Fig.11)

                             i) WNR3500Lv2 Without Serial Cable connected :-


                                                                                                                      fig. 10

 

                         ii)WNR3500Lv2 With Serial Cable Connected :-

 

                                                                                                                      fig. 11


STEP 2:

Connect your PC to the LAN port of WNR3500Lv2 with a straight cable and assign a IP “192.168.1.X” in your PC (assuming the router's default IP is 192.168.1.1).

STEP 3:

Now switch on your WNR3500Lv2. You must be able to -

  • See router's booting log in minicom.
  • ping 192.168.1.1 (router's default IP) from your PC, as soon as router finishes its booting.

STEP 4:

Now to enter in boot prompt, you have to simultaneously press “Ctrl” and “c” key of your PC and reboot your router.

Following picture (Fig.12) depicts how your screen will look if you are able to enter boot prompt.

                                                                                                                      fig. 12


STEP 5:

Now type “tftpd” to go into “TFTP Server mode” (Fig.13).

                                                                                                                      fig. 13


STEP 6:

Now go to the directory containing the “chk” file you have downloaded from MyOpenRouter site and upload the “chk” file using the following command,

“ tftp -m binary 192.168.1.1 -c put FIRMWARE_NAME “

e.g. “ tftp -m binary 192.168.1.1 -c put ddwrt-wn3500lv2.chk “ (DD-WRT Firmware).

“ tftp -m binary 192.168.1.1 -c put tomato-wnr3500lv2.chk “ (Tomato Firmware).

 

STEP 7:

Now the image will be written in your router flash and will be rebooted automatically after successful write.

After a certain time open your internet browser and type 192.168.1.1, you will have WebUI of your target firmware for configuring your router.

Congratulations, your router is now ready to use!

shibby
shibby's picture
pinout:

pinout:
6 - GND
5 - RX
2 - TX

btw useful tutorial. On windows you can use "putty" program.

Subhra
Subhra's picture
Thanks shibby for pointing

Thanks shibby for pointing the pinout.

Peter Redmer
Peter Redmer's picture
Hi Subhra/Shibby,

Hi Subhra/Shibby,

When I did this, I followed most of the directions in my previous tutorial, and with the put command I used the "-i" parameter rather than the "-m" parameter.

It seemed to work perfectly... what is the difference between the two? Is one better than the other or is it just preference?

Subhra
Subhra's picture
The purpose is to transfer

The purpose is to transfer the image file in binary mode.
In linux tftp client uses "-m" option and in Windows (I tested on Windows xp) tftp client uses "-i" option to specify the mode of file transfer.

Peter Redmer
Peter Redmer's picture
Thanks Subhra! Good to know I

Thanks Subhra! Good to know I was using the correct command for Windows.

Berk
Berk's picture
Updating this post to wipe my

Updating this post to wipe my previous question. This post is just a temporary progress report, to be replaced.

I failed to communicate with my new FTDI cable through a fresh Fedora install, so after a week I'm reinstalling my PC with Ubuntu 32bit (takes less memory than it's 64bit version, though I have a dual core 64bit), found a FTDI driver from Ubuntu Software Center, installed IDE's but still have some steps to set up this machine.

Everything apparently worked from Mac OSX Lion on another of my systems, any suggestion to make the flash 'stick' from there would be helpful. I tried with and without -b.

Ubuntu not yet tested with these steps...

levsa
levsa's picture
Thanks for the info!

Thanks for the info!

But it seems like it may work without the serial cable, at least it did for me. Although I had installed tomatousb before I failed to upgrade it to 093-AIO, and maybe it does replace the CFE? Anyway, once the power led was blinking and ping was returning TTL=100 (means in CFE), I could configure my laptop eth to 192.168.1.9 and tftp to 192.168.1.1 and put the chk (093 failed here as well, but 087 work). If tftp put succeeds, it means CFE did run the tftp daemon automatically (without need to use serial cable). Worth a try!

/levsa

jouell
jouell's picture
I wonder if you could do

I wonder if you could do without the cable via wireless since the client can see the 192.168.1.1 address...Maybe not if the network is isolated?

jouell
jouell's picture
If you buy this cable:

If you buy this cable:

PL2303HX USB To TTL To UART RS232 COM Cable Module Converter

http://www.amazon.com/gp/product/B008AGDTA4/ref=oh_aui_detailpage_o00_s0...

this pin outs as above are;

6 5 4 3 2 1
black white none none green none

XP drivers are here: http://www.prolific.com.tw/us/showproduct.aspx?p_id=225&pcid=41

Putty works.

jouell
jouell's picture
I wonder if you could do

I wonder if you could do without the cable via wireless since the client can see the 192.168.1.1 address...Maybe not if the network is isolated?

jouell
jouell's picture
If you buy this cable:

If you buy this cable:

PL2303HX USB To TTL To UART RS232 COM Cable Module Converter

http://www.amazon.com/gp/product/B008AGDTA4/ref=oh_aui_detailpage_o00_s0...

this pin outs as above are;

6 5 4 3 2 1
black white none none green none

XP drivers are here: http://www.prolific.com.tw/us/showproduct.aspx?p_id=225&pcid=41

Putty works.