Recently, I killed my Linksys WRT54GL Router accidentally by upgrading it from HyperWRT to DD-WRT firmware. So, it looks like that you cannot upload a Linux firmware when another Linux firmware is already running.
I took me two days and tried may ways to recover it. Finally, thanks to DD-WRT’s guide to help me to recover this bricked WRT54GL router successfully. The following are steps to do recovering:
Symptom: Power light keeps blinking very quickly. I can ping the router but I cannot access it by any method.
1. 30/30/30 Reset:
(1) Disconnect the router from UTP cables (not the power cable).
(2) Push reset button for 30 secs.
(3) Without releasing reset button, disconnect power cord.
(4) Hold the reset button for another 30 secs.
(5) Replug the power cord.
(6) Still hold the reset button for another 30 secs.
(7) Release the reset button and give the router about 10 secs to resettle.
(8) Disconnect power cord for another 10 secs and then reconnect.
(9) All should be in default settings now.
2. Download the Linksys Original Firmware for WRT54GL to your local PC
3. Enable TFTP in your PC. Windows XP’s CD contain the TFTP. You need to copy it to your local computer. Windows Vista has TFTP, but you need to enable it. For Linux users, you need to install a TFTP client package.
4. Setup IP address for your Router:
arp -s 192.168.1.1 aa-bb-cc-dd-ee-ff (aa-bb-cc-dd-ee-ff is the MAC address of your router. You can get it from the bottom label of your router.) ping 192.168.1.1 (You should be able to ping it.)
4. Use TFTP to send WRT54GL Original Firmware to the Router.
tftp -i 192.168.1.1 PUT code.bin (code.bin is the original firmware.)
There is a trick here. I tried many times, it always failed due to timeout. The trick is you need to unplug the power and plug again before you send file. You also need to TFTP the file within several seconds after plug the power.
5. After you can boot from the Linksys Original Firmware, it means you already recovered the router. Next step is you can download the DD-WRT firmware and TFTP it the router.
For more information, please visit: http://www.dd-wrt.com/wiki/index.php?title=Recover_from_a_Bad_Flash
