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Linksys WRT1900AC

WRT1900AC was announced on 6th of January 2014 as a router developed to be used with OpenWrt. Despite Linksys announcement of working with OpenWrt community no patches and no info was shared for the next months.

  • On the 3rd of April Belkin posted link to ftp server containing patches adding WRT1900AC support. They couldn't be applied because of being incorrectly posted, not signed off and adding binary wireless driver ap8x.ko.
  • 5 days later a patchset in the form of single e-mail was posted to the openwrt-devel. It was malformed and not signed off, so still couldn't be applied. Release of wireless driver has been postponed.
  • Linksys started shipping on 10th or April
  • Wireless driver was announced to stay closed source on 30th of July. It'll likely consist of pre-built closed source part (so called "library") and probably some open source file calling kernel APIs.
  • Oddly, the wireless driver source was later distributed as part of the GPL release of the stock Linksys firmware. This driver requires significant refactoring before it can be included in OpenWRT.

At this point it is not possible to compile a fully working (including WiFi) customized OpenWrt build for WRT1900AC.

On Christmas Eve 2014, Marvell released an updated driver for the 88W8864 WiFi chip as found in the WRT1900AC to the openwrt developers mailing list

At this time it is now possible to compile an image off trunk with this new driver. A prebuilt image can be found here:

The latest trunk image is built with a 3.14 3.18 kernel. Current testing with 3.18 shows improvement in network performance.

See also Update on Linksys WRT1900AC support forum thread for official statement.

Switch to Port layout

Supported Versions

Version/Model Launch Date S/N OpenWrt Version Supported Model Specific Notes
v1 2014-03 - Trunk 43773 (as of 2014-12-25) Kernel 3.18 recommended (better SoC support compared to Chaos Calmer's 3.14 kernel)
v1.1 2014-x - - -

NOTE: Anything not included in model specific notes, or where a short comment couldn't be included on the notes.

OEM source code available at: link

Hardware Highlights

SoC Ram Flash Network USB Serial JTag eSata
Marvell MV78230 256 MiB 128 MiB 1x2.0 1x3.0 Yes Yes

Where to get firmware?

There are a few different builds of OpenWRT for the Linksys WRT1900AC you can try:

1) Chadsters's McWRT release of the old AA version
Many of us have been running this in its various release versions for the last 3-4 months successfully before moving to one of the newer builds (see below). It's stable but based on older code. (Also reported that some clients, e.g. 2008 unibody macbook running 10.10.1 os x, will not connect to the newer builds below, so try this first, older, build if you encounter problems with either of the other two options below.) Direct link to the current (1.0.8) image file (save it to your computer somewhere):

2) CC snapshot release from openwrt downloads page:
This will always have the latest trunk build. Currently based on 3.18 kernel, it is a bare minimum build so you will have to use opkg to add luci and any other extra packages. To install luci just follow the directions here:

3) lifehacksback's OpenWRT trunk of CC with the latest 3.18.1 kernel (includes luci plus other packages)
I've been running this for over 20 hours now and it's been the best version so far for me - fast and stable (new permanent link to a "known good" build) and this is his testing branch

4) Kaloz's evolving snapshots of trunk (includes luci plus other packages)
Same as lifehacksback's, but incorporating latest bugfixes/features
This is constantly evolving so is the current "latest and greatest." Not run it myself (yet), but others have tried it successfully and it's done everything they've wanted.

Note that 2), 3) and 4) are from "trunk" and so you may have issues either now or in the future installing additional software packages on the router, since trunk is a moving target.

Some people are also reporting wireless issues with 2), 3) and 4), while for others it's been fine. Again, 1) is the conservative choice.

How to flash the firmware to device?

To update any of three above you log into your wrt1900ac router by opening a web browser and typing:

on the right-hand side you need to enter the password (default is admin)

NOTE: you should always update firmware using a wired (ethernet) connection to your router, NOT over WiFi.

You may want to save your old Linksys settings if you've changed any of them. You CAN'T import them into OpenWRT, but you will be able to restore them if you need to go back to Linksys's firmware. To backup the Linksys settings, click "troubleshooting" on the left and then click the "diagnostics" tab. Under "router configuration" look to the right for "restore configuration" and click "backup."

To put OpenWRT on, click "connectivity" on the left then look on the right for manual update firmware.

Click Choose File and find the .img file you saved from the links above of any of the three builds.

Watch the progress meter then wait a couple of minutes.

You may need to refresh the network connection of your computer. This will depend on your operating system, but worse case just reboot the computer. Some ISPs's ASDL/cable modems won't let you back onto the Internet until you turn off the modem, turn off the router, turn the modem back on, then turn the router back on again.

Now you should be able to go to: (if you chose firmware 1))
or (if you chose 2) or 3))

and see the new OpenWRT firmware on the router. Change the login password (none set initially); this is the ADMIN password for the router, NOT your WiFi password to connect devices.

You'll then need to go in and set up what you want to. I think you might need to turn on and set ESSIDs and passwords for the two (WiFi) radios (one 2.4GHz, the other the 5GHz radio) in all of the firmwares. WPA2 might be the only encryption/cipher option that will work.

If you decide you want to go back to Linksys's firmware then you need to download their latest one from: (choose downloads, hardware version, then click the download link under Firmware).

Flashing back to Linksys ("stock") firmware is done by logging into to OpenWRT: (if you tried OpenWRT firmware 1))
or (if you chose OpenWRT firmware 2) or 3))

(enter the ADMIN password you set when you first logged in to OpenWRT)

and finding System menu → backup / flash firmware.

Choose the linksys (stock) .img file you saved above from Linksys's site.

(again you might want to first save your OpenWRT configuration for future flashing; choose Generate archive. But note, if you're jumping between big releases of OpenWRT (e.g. Chadster's AA to lifehackback's/Kaloz's CC) it's best NOT to restore settings but instead set them up by hand again from scratch.)

When updating between OpenWRT builds/releases it's always recommended to flash back to stock (Linksys) FIRST, then reflash again from stock to the new/different OpenWRT build. This is a precaution that could help you out if there are any problems in the flashing process.

Are you experiecing wireless disconnects with the CC build?

Preliminary reports show adding the following to your wireless settings should help those who are experiencing client disconnects issues (in particular Apple products).

Using UCI you can make the changes accordingly from the command line:

root@wrt1900ac:~# uci set wireless.@wifi-iface[0].disassoc_low_ack=0
root@wrt1900ac:~# uci set wireless.@wifi-iface[1].disassoc_low_ack=0
root@wrt1900ac:~# uci commit
root@wrt1900ac:~# wifi

In case something goes wrong with your firmware flash

This is contributed from forum user edgeman

I've found a way to manually switch the wrt1900ac from a trashed flash, to the secondary flash… It's done as follows:

Reset the router by holding the reset button in until the PWR light starts to flash {mine takes about 15 sec's} Once the power light stops flashing, you can power off the router with the power switch.

Turn the power back on and the PWR light will light. As soon as any other light turns on, power off the router with the power switch.

Turn the power back on and the PWR light will light. As soon as any other light turns on, power off the router with the power switch. Turn the power back on and the PWR light will light. As soon as any other light turns on, power off the router with the power switch.

Turn the power back on and the PWR light will light. This time just let the router power all the way up. It should now be on the alternate firmware.

Yes, you will power off three times. Hope this works for you-all…


Flashing Firmware using a USB to TTL Cable


A working "USB to TTL" connection to the WRT1900AC (see picture below for connectivity)

A working serial interface like Putty or Tera Term (set speed to 115200 baud)

A TFTP Server running on a client workstation connected to the WRT1900AC LAN port

The TFTP Server client workstation Local Area Connection configured with IP Address

The firmware to load is in the TFTP Server ready for download.

Instructions: Startup:

Boot WRT1900AC At the 3 second interrupt boot delay press space bar or any key U-Boot Commands:

setenv firmware_name openwrt-armadaxp–jffs2-128k.img setenv ipaddr setenv netmask setenv serverip run flash_pri_image Optional:

If you want be 100% sure you are running a firmware image. Then you can flash the firmware to both the primary and secondary image locations by substituting "run flash_pri_image" with "run update_both_images".

Mac Video Tutorial - made by lifehacksback

Windows Video Tutorial

Coming Soon - made by lifehacksback

Linux Video Tutorial

Coming Soon - made by lifehacksback

Serial Port


1 2 3 4 5 6
GND RX ? TX ? ?


The header uses a 2.0mm pitch, which means the more common 2.54mm pitch connectors will not fit properly. This includes the female connectors on popular USB-TTL adapters. However, removing the plastic casing from 2.54mm female connectors allows for a stable-enough connection in a pinch.

FIXME TODO: copypaste from template_device

Manufacturer's site: Linksys WRT1900AC


For some Help with the Tags, please have a look here: tags

toh/linksys/wrt1900ac.txt · Last modified: 2015/03/22 20:57 by tehprofessor