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Matthew Chapman on Lenovo laptop internals

Matthew Chapman has a nice set of blog posts that go into detail about Lenovo internals, including some firmware and ACPI details, all because of a new battery:

Unlocking my Lenovo laptop, parts 1-3

Two months ago, I bought a new battery for my Lenovo laptop (a ThinkPad X230T). I was about to go away on holidays and wanted a battery that could last me through a plane flight; the original battery was by then barely lasting ten minutes. Little did I know that I was about to […]

In part 1, we looked at the communication between a Lenovo Thinkpad X230T laptop and battery, and discovered that there a challenge-response protocol used to authenticate ‘genuine’ Lenovo batteries. On the laptop side, this – and battery communication in general – is implemented in a component known as the embedded controller (EC). […]

In part 2, we discovered that a embedded controller update is performed by uploading a small ‘flasher’ program to the EC. This flasher program is then responsible for programming a new firmware image to the EC’s internal flash memory. However, both the flasher program and part of the firmware image are encrypted: the old (currently running) EC firmware decrypts the flasher program, and the flasher program then decrypts the new firmware update. This creates a bit of a chicken-and-egg problem that prevents discovering the encryption algorithm from firmware update files alone. […]

Blog series:
http://www.zmatt.net/unlocking-my-lenovo-laptop-part-1/
http://www.zmatt.net/unlocking-my-lenovo-laptop-part-2/
http://www.zmatt.net/unlocking-my-lenovo-laptop-part-3/

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