As usual, use it at your own risk. I am not to be held responsible for your actions.
Supported devices: WNR1000v2 (tested by me), WNR1000v2-VC (provided by Comcast for free; tested by Douglas Fraser)
Notice: Upgrade WNR1000v2 to the latest factory firmware: 1.1.2.58. Otherwise, the power LED may not behave properly.
You need to place the device into failsafe mode. For booting into failsafe mode, you need to power up the device while holding the reset button with a pin. The power LED should have an amber colour. Hold the button until it is starting to flash green. It starts to flash green after it flashes the amber LED for six times. After that, the device is in failsafe mode, accepting a firmware via its TFTP server. The device should respond to pings at 192.168.1.1, although the responses may be malformed.
Configure your ethernet interface with a 192.168.1.0/24 IP address. I use 192.168.1.2 with netmask 255.255.255.0 but it should work with any free address from that block.
You need a TFTP client for this purpose. You may check the OpenWrt wiki for more information if you aren't familiar with the procedure.
With the OS X tftp client, and the Linux tftp client, the flashing procedure is something like:
tftp 192.168.1.1
> binary
> trace
> put openwrt-ar71xx-generic-wnr1000v2-squashfs-factory-barrier-breaker-r44095.imgtftp 192.168.1.1
> binary
> trace
> put openwrt-ar71xx-generic-wnr1000v2-vc-squashfs-factory-barrier-breaker-r44095.imgPlease don't use the WNR1000v2 firmware file for the WNR1000v2-VC model. Every time you do that, a kitten dies.
The power LED turns off during the upload. If it starts to flash green after the upload, then the firmware is rejected (usually the case with a corrupted or wrong firmware). Otherwise, it should be green and it stops flashing (but sometimes it may stay off). You should wait until the device finishes the upgrade procedure. Usually it is under three minutes. It should boot into OpenWrt.
If the connection drops during the upload, you may end up with a corrupted firmware and the device is booting into failsafe mode. Just repeat the flashing procedure.
Please notice that the power LED flashes green during the normal boot. However, it flashes at a faster rate compared to a device in failsafe mode. If unsure, let the device to stay in that state at least for a minute before deciding that it needs reflashing. After a normal boot, you should get a solid green on the power LED.
The Chaos Calmer patch was created against r44154. It was tested succesfully on WNR1000v2 and WNR1000v2-VC, but the device may require a power cycle after the flash. It may boot in (an unusable) failsafe mode. This happened on WNR1000v2 by going from Barrier Breaker to Chaos Calmer via TFTP flashing.
For building it, you can not use the Barrier Breaker config. For creating the build config, you need to pick the "Atheros AR7xxx/AR9xxx" Target System, the "Generic" Subtarget, and optionally the WNR1000v2 driver profile.
Please notice that the images may not build succesfully without a clean tree and config.
You need an OpenWrt Buildroot. I use Debian 7.x for this purpose.
# Aka cloning this particular gist
git clone https://gist.github.com/ef49c8a4df81c8896153.git
cd ef49c8a4df81c8896153
# This is the Barrier Breaker branch
git clone git://git.openwrt.org/14.07/openwrt.git
cd openwrt
# Apply the patch for WNR1000v2/WNR1000v2-VC support
patch -p1 < ../wnr1000v2+vc-barrier-breaker-r44095.patch
# Add the LuCI support into the OpenWrt tree
./scripts/feeds update luci
./scripts/feeds install luci
# Get the generic config for AR71xx
wget https://downloads.openwrt.org/barrier_breaker/14.07/ar71xx/generic/config.ar71xx_generic -O .config
# when doing the menuconfig, you need to go to LuCI > Collections and
# make sure that {*} luci is selected, otherwise LuCI is built as module
# and it won't be available into the built image, only the package is built
make menuconfig
# The final step for building the image. You may replace "make" with
# "make -j number-of-cpu-cores+1" for faster building on a multi-core CPU
makeThe images will be in the "bin/ar71xx" directory. After that, follow the above Install instructions.
I remember being plagued by tftp issues under Windows. Ended up using https://github.com/gagle/node-tftp - in fact, I have tried this on all platforms that I normally use.