Update Firmware Linksys WRT54GS v7.0 & 7.5

Installation

This flash method applies to EON, INTEL, and SAMSUNG(?) flash chips.
NOTE TO WINDOWS USERS: The native TFTP Client is disabled by default, so enable it before proceeding (or download a third party TFTP tool, ex: TFTP2 or TFTP32/TFTP64). In Windows, go to "Add or Remove Programs" (or "Programs and Features", depending on the Windows version) from the Start menu or Control Panel, then the Windows Features section, and scroll down to select TFTP Client to enable it.

1. First download vxworkskillerGSv7-v3.bin and dd-wrt.v24_micro_generic.bin
2. Set a static IP address (outside DHCP range e.g. 192.168.1.10), connect the PC ethernet to a router LAN port
   • Linux command: ifconfig eth0 192.168.1.10
   • Windows™: go to Control Panel->Network and Internet->Network Connections
     1. Right-click, go to the LAN device properties, then find and open the TCP/IPv4 Properties
     2. Select "Use the following IP address" to set a static IP (e.g. 192.168.1.10, subnet 255.255.255.0)
        • Ensure this static IP is outside the DHCP range
3. Unplug the router, then hold the reset button while reconnecting power for about 20 seconds.
4. Open your browser to http://192.168.1.1/
5. Use the Firmware upgrade option under the Administration tab to flash vxworkskillerGSv7-v3.bin.
6. After the dialogue about disconnecting the power cord is shown, disconnect the power cord and reconnect it.
7. Wait for FIVE FULL minutes, then disconnect the power cord for 10sec and reconnect it.
8. Transfer the firmware using TFTP
   • Linux command: tftp -v -m octet 192.168.1.1 -c put dd-wrt.v24-micro_generic.bin
   • Windows™ Command Prompt (cmd): tftp -i 192.168.1.1 put dd-wrt.v24_micro_generic.bin
9. Wait for tftp to finish, then the router will automatically reboot. Finally, access the GUI at 192.168.1.1
10. Watch the router lights: the power light will eventually come on, followed by the WLAN light
    • Note: If the router does not boot automatically, even after a power cycle, reset again, per step 3.

[edit] Alternate method to flash WRT54GSv7.2

There is no resetting in the middle of this process. This method has also been used on WRT54Gv8 (not GS), and should work on the v7.0. My WRT54GSv7.2 has an EON EN29LB160AB-70TCP flash chip and 16MB Samsung RAM.
tiger12506 has successfully performed this on two WRT54GS v7.2 with CGNE serial numbers. He felt that he had bricked one of the routers at first. Messing around with JTAG cables taught him some things, but be absolutely sure that you have tftp set to binary or octel. If you leave tftp in ascii it will appear to work but the flash won't take.
1. Use the web interface to reset the router to factory defaults.
2. Manually set a static IP (e.g. 192.168.1.10 or any address outside the DHCP range)

• Linux: sudo ifconfig eth0 192.168.1.10

3. Use the web inferface to update the firmware to vxworkskillerGSv7-v3.bin.
4. Windows: tftp -i 192.168.1.1 PUT dd-wrt.v24_micro_generic.bin

• Linux: enter tftp mode with # tftp 192.168.1.1

 tftp> mode binary
 tftp> put dd-wrt.v24_micro_generic.bin
 tftp> quit

5. Start a continuous ping: ping -t 192.168.1.1 (-t is Windows only) This will time out repeatedly, then the router will respond about two and six times, time out again a few times, and then start responding to pings.

• [This is where tiger12506 had trouble, but after a long reset, and some short resets, more and more lights came on until finally the WLAN light came on and the router functioned normally running DD-WRT]

6. Access the DD-WRT GUI at 192.168.1.1