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Installing Kamikaze 7.09 on WRT54GL

Monday, September 1, 2008 | 0 comments

Today I finally decided to flash my router with a new firmware: Kamikaze version 7.09. Despite the promise on the OpenWRT website: "Last day in August - final release: OpenWrt Kamikaze 8.08 Release", no new release was available on the first day of September. Someone in the forum stated that "it's done when it's done". I can live with that, but why not mention this on the home page?

Downloading Kamikaze and installing

Anyway, back to the issue at hand: downloading and flashing a Linksys WRT54GL router. First I dug up my old router, a D-Link DI-604; given to me by my brother Marco when I moved to Mexico. I had never flashed a router before, and was aware of the small risk that I might end up with a non-working router, and no way to safely connect to the Internet. Hence why I decided to keep the DI-604 at hand.

Part of the information sticker glued to the bottom of my WRT54GL.
Part of the information sticker glued to the bottom of my WRT54GL.

After I had disconnected the WRT54GL, and tested the DI-604 - it worked without any problems - I browsed to the Download page of the OpenWrt site. Since the serial number of the router started with CL7B I knew the router was a version 1.1 model WRT54GL. Moreover, the sticker at the bottom just stated so. Hence I was sure that Kamikaze would work on my router. Since I had read that the 2.6 kernel didn't support Wi-Fi (yet?) I decided to download a firmware with the 2.4 kernel. So after a few mouseclicks I ended up in /kamikaze/7.09/brcm-2.4/ - brcm because the WRT54GL uses a Broadcom - and downloaded openwrt-wrt54g-2.4-squashfs.bin.

WRT54GL firmware upgrade via the web user interface.
WRT54GL firmware upgrade via the web user interface.

When Firefox reported the file as being downloaded I checked its integrity using the md5sum program. I highly recommend to do this as well if you're going to follow the steps in this blog post. The sum - actually a digest - reported by the program was identical to the one reported on the OpenWRT website, meaning that I could be quite sure that the file was not corrupted during download. Then it was time for quite a scary step: flashing the downloaded file. So I disconnected the UTP cable connected to my computer from the DI-604 and reconnected it to the WRT54GL. This was now the only UTP cable connected to the Linksys router.

I had decided to use the web user interface method to upload/flash the firmware, because it sounded the easiest method to me. So I browsed to using Firefox and selected the file I had just downloaded from the OpenWrt website in the Linksys web user interface. After I had clicked the upgrade button and the rectangular area above "Upgrade must NOT be interrupted!" slowly started to fill with vertical bars, I decided to step away from the computer to avoid accidentally interrupting the flashing process.

PuTTY as a telnet client connected to Kamikaze 7.09 running on a Linksys WRT54GL.
PuTTY as a telnet client connected to Kamikaze 7.09 running on a Linksys WRT54GL.

When I returned to the computer Firefox displayed a page which stated "Upgrade is successful". Next, I started PuTTY and created a session for the WRT54GL: IP address and port 23 (telnet). I saved the session, and then opened it and was greeted by the Kamikaze 7.09 welcome screen.

Post-flashing clean-up and configuring WAN

After the excitement of having sucessfully flashed - instead of bricked - my router, I followed the installation instructions I had read, and typed the following commands:

nvram set boot_wait=on
nvram set boot_time=10
nvram commit && reboot

That last line is probably the most cryptic one. It means: write the changes to the non-volatile random-access memory for real and (&&) if that was successful, reboot the router. Without the commit, the two earlier settings would be lost after a reboot.

According to the aforementioned installation instructions, after this point the NVRAM is no longer used, and it is recommended to clean the NVRAM by downloading a script and executing it. Downloading a script: first I had to configure the WAN port for Internet access. Or so I thought, it turned out that the default is DHCP (for cable internet), and hence didn't need to configure anything as the following command shows:

uci show network.wan

The uci (unified configuration interface) program makes viewing and altering configuration settings very easy. The settings are stored in configuration files in /etc/config.

Note: I recommend to use the passwd command to set a strong password and connect using SSH before you reconnect the UTP cable to the WAN port. I am sure that I am overcautious in this regard, but now is as good a time as any to set your router's password to something secure.

After I had connected the UTP cable coming from my cable modem to the WAN port of the WRT54GL I changed to the temporary directory, downloaded the NVRAM clean script, and executed it using the following instructions:

cd /tmp
wget http://downloads.openwrt.org/people/kaloz/nvram-clean.sh
chmod a+x nvram-clean.sh

The latter reported:

Before: size: 10758 bytes (22010 left)
After: size: 3279 bytes (29489 left)

After I had commited the changes - don't forget to do this - using nvram commit I deleted the NVRAM clean script using rm nvram-clean.sh.

Configuring Wi-Fi

The final step I had planned for today was making Wi-Fi work with my PDA, a Dell Axim X51v. The highest security setting supported by this pocket PC while running Windows Mobile 5 is WPA-PSK (Wi-Fi Protected Access, pre-shared key mode) using TKIP (Temporal Key Integrity Protocol).

After I had done some reading on how to set up Wi-Fi it was not entirely clear how to use uci to set things up: most examples used the NVRAM (the old way), and I was not sure if using encryption psk implied TKIP.

I decided to follow the instructions given in Configure WiFi encryption. However, when I tried to install nas I got the following message:

Package nas ( installed in root is up to date.
Nothing to be done

So it seems that nas comes out of the box with Kamikaze 7.09.

Next I followed the instructions on configuring WPA (PSK) encryption using uci. However for some reason my Axim was not able to connect to the router. After a nice cup of tea I decided to give it one more try, and bingo: my PDA connected to the WRT54GL, and I was able to browse the Internet.

Looking back through the lines of the saved PuTTY session, the following instructions did the trick for me:

uci set wireless.wl0.disabled=0
uci set wireless.cfg2.encryption=psk
uci set wireless.cfg2.key=SomeLongPassPhrase
uci set wireless.cfg2.ssid=YourNetworkName
uci commit wireless && wifi

One thing I noticed though: each time I disabled the Wi-Fi on the Axim pocket PC, a line showed up in PuTTY - still connected to the WRT54GL:

wl0: Invalid argument

I used Google to find more information on this. From what I've read, each time this line is reported, Kamikaze also resets the Wi-Fi stack, and hence breaks off all connections you might have via Wi-Fi on other computers (oops). The good news is that this seems to have been fixed in recent builds of Kamikaze. However, after I rebooted the router, and reconnected to it using PuTTY I was no longer able to reproduce the wl0: Invalid argument message.


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