Disabling wireless card whitelist on ThinkPad T410

Recently I bought myself a Lenovo ThinkPad T410. All in all it's a wonderful laptop, fast, robust, and a testament to enduring ThinkPad design. The one issue I had with it (other than getting the ACPI backlight working with Arch, but that's a post for another day) was the the hardware whitelist in the BIOS. When I plugged in any Mini PCI wireless card, instead of booting my laptop would present me with:

1802: Unauthorized network card is plugged in - Power off and remove the network card

System is halted

Not only was this rather limiting, I also don't like not having control over my own hardware. I found two promising methods to go about disabling this "feature." The first and less potentially damaging of the two was to modify the card's ID so the BIOS sees it on it's whitelist. After doing that though I would have had to patch my wireless drivers with the new ID, and then have to always worry with updates breaking it. To me it doesn't seem like an elegant solution.

The next option was to modify the BIOS itself. If done wrong this can brick your laptop, so it's not really recommended. There are lots of instructions online on how to patch the BIOS file yourself, but I was a bit apprehensive seeing as my skills with assembly are pretty basic and my skills with modifying hex are non-existent. 

With a bit of searching I found an already patched bios for the T410 done by user sovem on https://www.bios-mods.com. (links at the end of the post) I checked to make sure it had worked for other people, I really didn't want to brick my new laptop. It looked ok so I decided to give it a go. 

Step 1: Burn 6iuj29us.iso to a cd.

Step 2: Boot from the cd and flash BIOS.

Step 3: Make a FreeDOS USB stick (unetbootin is the easiest way) 

Step 5: Copy the bios_mod folder to the USB stick. 

Step 6: Boot from flash drive and select "Load FreeDOS without drivers"

Step 7: Run flash.bat

With the new BIOS the laptop no longer halts on boot, but it will still turn any wireless cards off with a hardware rfkill. To stop this you have to block pin 13 on the card. 

I just covered it with a piece of tape. After that everything worked fine and my OS saw both cards I had plugged in.

Links:
Modded BIOS
Mirror to files