GregLedet.net Adventures in networking, security, and other things

DD-WRT and the WRT54G-TM

So I do a lot of DD-WRT how-to's. I don't know why, I guess it's just that I seem to put DD-WRT on a bunch of different routers and decide that I'm going to document what I've done.  Today's how-to is for the WRT54G-TM.  Let me give you a little info on the WRT54G-TM.

The WRT54G-TM (TM stands for T-Mobile) is also called the T-Mobile "Hotspot@Home" service. It allows calls to be made via T-Mobile's GSM network or via WiFi Unlicensed Mobile Access (UMA), using the same telephone and phone number (a special dual-mode phone designed for the service is required e.g. Blackberry Pearl 8120). Additionally, once a call is in progress, one may transition from WiFi to GSM (and vice versa) seamlessly, as WiFi signal comes and goes, such as when entering or exiting a home or business. A special router is not needed to use the service, but the T-Mobile branded routers are supposed to enhance the telephone's battery life. This is the only known tweak to the TM version of the firmware.  Obviously, none of this will be worth anything seeing as you're about to flash it with DD-WRT.

The hardware appears to be like WRT54GL however has 32MB ram and 8MB flash.  Yeah, this thing is a monster.  Until not that long ago the only way to upgrade this router was through a JTAG cable and header, but luckily we don't have to worry about that anymore.  Let's get to it.

First off, download the software you're going to need. Here's a rar file with everything you're going to need. In the archive are 3 files:

CFE_Updater-WRT54G-TM.bin
dd-wrt.v24-13064_mega_generic.bin
tftp2.exe

The upgrade is pretty straight forward, but it has a little twist.  The default LAN IP Address of the Linksys WRT54G-TM is 192.168.0.1.  The default IP for everything else is going to be 192.168.1.1.  A way around this is to simply setup 2 static IP addresses on your computer.  I setup 192.168.1.9 and 192.168.0.9, but you can put whatever you want as long as they fall within the /24 subnet of 192.168.1.0 and 192.168.0.0.

1.) As always DO A HARD RESET BEFORE YOU FLASH FIRMWARE. This does not mean hitting the reset button and saying you are done. This means doing the 30-30-30 reset. To do a 30-30-30 reset you must push the reset button with your router powered on. Hold it for 30 seconds with the router powered on. STILL holding it, pull the power cord for 30 seconds. Still holding it, plug the router back in and continue to hold the reset button for 30 more seconds. You will have held the button for a full 90 seconds without releasing it. You will not get a password renewal page as you have stock Linksys firmware on the router still.

2.) Open a command prompt window and type ping -t 192.168.1.1 and hit enter. Leave this window open. We're going to come back to this later, but you need to keep this open.

3.) Log into the WRT54G-TM's web interface @ http://192.168.0.1 and go to the Administration Tab - Firmware Upgrade. Upload the CFE_Updater-WRT54G-TM.bin to the router.

!!!ATTENTION!!! You MUST wait at least 5 minutes after clicking the Upgrade button to allow the CFE_Updater to replace the stock CFE on the router and for it to erase the rest of the flash, otherwise you will brick your router.

A few seconds after clicking the Upgrade button the Linksys web interface will report that the upload has been successful and the power light will begin flashing on the router. Do NOT assume that the CFE replacement/flash erasing/reboot process has finished as the power light will continue to flash after it has rebooted. So there is no way to tell when it is ready for you to TFTP the DD-WRT firmware to it except when you begin to see the ping respond.

So once it is finished replacing the stock CFE and erasing the rest of the flash, the router will reboot. When the router is ready for the TFTP upload of the DD-WRT firmware, you will see the ping -t 192.168.1.1 begin to respond in the command prompt window that you opened before.

4.) Open up the TFTP utility and set it up like this:

The file there is the path to the dd-wrt.v24-13064_mega_generic.bin in the archive

Now click the Upgrade button. Once the firmware is sent to the router, it will reboot. The power light will change from flashing to solid when it is ready to be configured.  The default IP will be 192.168.1.1.

If you do not see a progress bar as the tftp utility transmits the file, you may need to power cycle your router. Wait until the tftp utility has finished its attempts, then power cycle (possibly waiting a few seconds) and wait until you can ping 192.168.1.1 before clicking Upgrade again.

A few notes:

• Tornado has made it so that the router will retain it's MAC Address that is on the label on the bottom of the router with the new CFE replacement.
• Tornado is in the process of making a revert bin for those who may choose to revert back to the stock Linksys firmware (god only know why)

Many thanks goes out to Tornado, Eko, and Brainslayer for their work on this! Also, thanks to Luniz2k1 that wrote the original how-to that my lazy ass ripped off to make this one.