Chapman: Unlocking my Lenovo laptop

In a lengthy blog series (part 1, part 2, and part 3), Matthew Chapman described the process of getting a non-Lenovo battery to charge in his Thinkpad laptop. He reverse-engineered the authorization that real batteries do and changed the code in the embedded controller (EC) on the laptop to allow other batteries to charge. "I look in BIOS to see where these messages are coming from. Both this message and the original unauthorised battery message are displayed by LenovoVideoInitDxe.efi: don't ask me why this code is in this module rather than somewhere more relevant (may I suggest LenovoAnnoyingBatteryMessageDxe.efi?), but it might have been convenient to put it in the video initialisation module as the message is displayed when the screen is cleared post-POST [Power-on self-test]."(Thanks to Neil Brown.)