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Actiontec GT704WG

The device is based on Texas Instrument AR7. It uses the target.ar7 in OpenWrt.

  • Kamikaze 8.09.2 seems to work
    Note: Package repo will not work with Kamikaze 8.09.2
  • Tested Backfire 10.03.1: Wireless not working, Package repo working
  • Tested Attitude Adjustment 12.09-beta2: Wireless working, tested client mode to WPA2 device successfully. Package repo appears to be working but insufficient memory errors prevent even the smallest packages to install. You may need to build your own image using buildroot if additional software is needed. Web interface causes very high CPU load.

Supported Versions

Version/Model S/N OpenWrt Version Supported Model Specific Notes
1A+ - Kamikaze 8.09.2 -

Hardware Highlights

CPU Ram Flash Network USB Serial JTag
TI AR7@150MHz 16MB 4MB 4 + DSL Device Only (?) Yes Yes

Flash layout

partition start end description
mtd2 0x90000000 0x90010000 ADAM2 bootloader
mtd1 0x90010000 0x900d0000 kernel
mtd0 0x900d0000 0x903e0000 squashfs filesystem
mtd4 0x903e0000 0x903f0000 unused (?)
mtd3 0x903f0000 0x90400000 ADAM2 environment


Flashing with the Actiontec web upgrade has not been tested. The recommended flash procedure is to use the adam2 FTP server.

To access the adam2 FTP server, power on the device while holding reset button down for 3 seconds

If you are doing this from Linux, you will almost certainly first have to:

# echo 0 > /proc/sys/net/ipv4/tcp_frto

Otherwise, the transfer process will end up slowing down to approximately 512 bytes/minute.

Note: The range you will need to flash the squashfs image to spans all of mtd1 and mtd0 partitions.

$ ftp
Connected to
220 ADAM2 FTP Server ready.
Name ( adam2
530 Please login with USER and PASS.
SSL not available
331 Password required for adam2.
230 User adam2 successfully logged in.
ftp> passive off
ftp> quote SETENV mtd5,0x90010000,0x903e0000
ftp> binary
ftp> quote MEDIA FLSH
ftp> put "openwrt-ar7-squashfs.bin" "openwrt-ar7-squashfs.bin mtd5"
ftp> quote REBOOT
ftp> quit

Note that the power LED will not turn green with OpenWRT. This doesn't imply anything is broken as it does with the default firmware.

Note for Windows users
  • Windows' command line ftp client will start already out of passive mode, and in any case above command "passive off" will not work.
  • In the "put" command fails with a "550 Data Socket not ready" error, make sure windows firewall is disabled and/or the network connecting to the router is set as "home" or "work".
  • If you are experiencing a problem with "connection terminated by remote host", you need to add this key to the registry and reboot your computer: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\TcpMaxDataRetransmissions = 40 (DWORD, value in HEX) (CapinWinky).

Upgrading OpenWRT

If you have already installed OpenWrt and like to reflash for e.g. upgrading to a new OpenWrt version you can upgrade using the mtd command line tool. It is important that you put the firmware image into the ramdisk (/tmp) before you start flashing.

LuCI Web Upgrade Process

Terminal Upgrade Process

  • Login as root via SSH on
  • Use the following commands to upgrade.

cd /tmp/
mtd write /tmp/openwrt-ar7-squashfs.bin linux && reboot



Architecture: MIPS (little endian)
Vendor: TI
Bootloader: Adam2
System-On-Chip: TI TNETD7300
CPU Speed: 150 Mhz
Flash-Chip: ?
Flash size: 4 MiB
RAM: 16 MiB
Wireless: TI ACX111
Ethernet: Marvell 88E6060
USB: Device
Serial: Yes




Opening the case

Note: This will void your warranty!

  • To remove the cover take off the 4 rubber feet
  • unscrew the 4 screws under the rubber feet

Main PCB


3.3V serial is available on JP603 with the following pin out:

pin 1 : GND
pin 2 : TX
pin 3 : RX
pin 4 : NC
pin 5 : 3.3V
pin 6 : NC

Pin 1 is the closest to R441.


How to connect to JTAG interface, and how to reflash the device with JTAG tools

See port.jtag for more JTAG details.

According to the documentation JTAG is available conneting to:

RESET : R106
TRST : R112
TDI : R110
TDO : R109
TMS : R108
TCK : R107

Specific Configuration


This device works with both annex A and annex B modules. As an example, to install annex B module on Backfire, download the package 'kmod-sangam-atm-annex-b' from

Then copy the package on your router per scp. Here an example using a windows client with pscp, router at IP, user 'root':

pscp -scp "kmod-sangam-atm-annex-b_2.6.32.27+D7.04.03.00-R1_ar7.ipk" root@

Then access your router via SSH or telnet and do:

cd /tmp
opkg remove kmod-sangam-atm-annex-a
opkg install kmod-sangam-atm-annex-b_2.6.32.27+D7.04.03.00-R1_ar7.ipk
If it succeeds, remove the package from /tmp. Then reboot your device.

You can check your modem stats by

cat /proc/avalanche/avsar_modem_stats



config atm-bridge
    option unit     0
    option encaps   llc
    # Ask your ISP for the correct vpi and vci values
    option vpi      0
    option vci      35
    # Most of the time this should be set to "bridged," but some ISPs require "routed"
    option payload  bridged

config interface wan
    option ifname       nas0
    option proto        pppoe
    option username    "username"
    option password    "password"



config interface wan
    option ifname   ppp0
    option proto    pppoa
    option encaps   llc
    option vpi      0
    option vci      35
    option username "username"
    option password "password"

Restart your interface by

ifdown wan
ifup wan

Switch Ports (for VLANs)

VLANs are currently not supported.


The Actiontec GT704WG has one button. Not sure if it can be used with hotplug events.

Reset ?

Known Issues

  • pppoa does not start automatically
  • "eth0: rx dma ring overrun" in dmesg output under heavy traffic
  • qos does not work with pppoa (no traffic is forwarded if qos is enabled)
  • wifi is WIP
  • No VLAN support

Hardware mods

Adding Hardware Flow Control to the Serial Port

To add hardware flow control (CTS/RTS) to the serial port on JP603 add 100Ohm 0603 resistor to R614 and R615 locations.

Adding Level Shifting to the Serial Port

The GT704WG has a footprint for a MAX3232 voltage level converter. This will allow to directly connect a standard RS-232 to the router. After this modification JP603 will no longer work as the serial output is redirected to JP2 with the following pinout:

pin 1 : GND
pin 2 : NC
pin 3 : NC
pin 4 : RX
pin 5 : TX
pin 6 : RTS
pin 7 : NC
pin 8 : CTS
pin 9 : NC
pin 10: NC
pin 11: NC
pin 12: NC

material list:
1 MAXIM MAX3232 in soic-16
5 0.1uF 0603 capacitors
2 100ohm 0603 resistors
1 2x4, 2x5 or 2x6 2.54mm (100mils) pitch header 

1- remove R30 and R441. These are 100ohm, if you are careful in the removal you can re-use them for point #2 below
2- add 100ohm to R147 and R442
3- add 0.1uF to C17, C18, C19, C20 and C65
4- add MAX3232 to U4
5- add header to JP2 (pin 1 is the one closes to JP603 towards the edge of the PCB)

32/64MB RAM mod

The GT704WG uses one 128Mbit (8Mx16) PC133 SDRAM (54-pin TSOP II). The PCB is wired to support both 256Mbit (16Mx16) and 512Mbit (32Mx16). Using one 512Mbit device like MT48LC32M16A2 (or similar) your GT704WG will have 64MBytes of RAM. All is needed is to remove U105 and replace with the new chip.

The chips can be found mounted on old PC133 DIMMs or SODIMMS. 128/256Mb DIMMS with 4 chips are the best candidates.

I have done the modification using a generic 32Mx16 SDRAM (no brand). The Adam2 installed on my router will reset the memsize environment variable at every reboot so the mod will be useful only when using kernels with memory size auto detection (the stock firmware will not auto detect the memory size). OpenWrt will correctly size the memory regardless of the env settings.


toh/actiontec/gt704wg.txt · Last modified: 2015/10/18 17:00 by tmomas