A reverse engineer finds Kindle's hidden features

Amazon's Kindle e-book reader.

(Credit: Amazon.com)

A significant amount of skill with a soldering iron and some custom firmware has revealed a number of interesting features Amazon.com hid within its Kindle e-book reader.

Among the ones that hardware hacker Igor Skochinsky uncovered and described on his blog are a basic photo viewer, a minesweeper game, and most interesting, location technology that uses the Kindle's CDMA networking to pinpoint its position. There also are some basic location-based services that call up a Google Maps view to show where you are and nearby gas stations and restaurants.

I confess I was as interested in the reverse-engineering process, documented in three blog postings (first, second, and third).

Skochinsky started by scrutinizing the Kindle source code Amazon publishes. (Some open-source licenses, including the General Public License (GPL) that governs Linux that the Kindle also uses, require source code to be published when a product ships that uses it.) From the source he inferred the Kindle employed console software, which displays text output.

Through methodically testing electrical pins on an external port he eventually found the text output from the Kindle boot process. That showed the machine was using das U-Boot software to handle booting, during which stored software is loaded into memory. U-Boot offers an interactive shell with a command-line interface, and Skochinsky used that to laboriously piece together the Kindle operating system kernel used during its firmware update recovery process. From that he deduced the file format of firmware updates.

Getting a real Linux command line took more work. By looking at the file system, Skochinsky found a root password of "Fiona"--but also found that password had been changed before shipping. Using the firmware update process, he was able to swap in a new shadow file, which stores a garbled byproduct of passwords called a hash, that enabled him to use the hash from the original root password.

On reboot, he was able to control the system and see what processes it runs, what file systems it mounts, and what files are stored in its directories.

He also found that the interface is written in Java. Using the Jad decompiler software, he uncovered the hidden features and a number of keyboard shortcuts.

[wgilbert5]

Hacking the Kindle

Kinda funny thing happened to me on the way to get a Kindle. The company (Amazon) assured me they were out and would ship one to me when they got them in. That was a month or so ago and I haven't been notified my new Kindle is on the way yet, but they have assured me I can buy the books to put on it and they will let me download them as soon as my new Kindle is in my hands. So, then I read this and realize that, although I can't get one, this fellow can get one to hack and, in effect, cut up, and make a jalopy out of it. How nice! I'm really happy to know what I can do with it when (if?) I get it. Thanks Amazon!

[cfw123]

Delivery of Kindle's

Amazon (i.e. Kindle of course) is one of the most reliable companies when it comes to deliveries -- it does what they say. In this case delivering on a first ordered first delivered basis. But it has been my observation that they actually deliver earlier than they promise as a matter of policy, as it greatly cuts down on the chit chat.

In my own case, I ordered on Nov. 16th when it was first announced, but my order didn't make the five hour and a half period it took to ship out their first year's supply. But I did get it on Dec. 4th, and have really loved it ever since I got it. My son didn't order his until I got mine, and is still waiting, but expects his by the end of next week. I did hear that it is taking a month from order to delivery at this time, and it will be June before they can ship immediately upon receipt of an order. Personally I think this is very optomistic, since the orders should really zoom once enough get delivered and other people can see how great it is. And I expect businesses will really order them in bulk like they do the blackberry for their roving marketeers in order to keep them up to date, and provide handouts without going to Kinko's for meetings. Charles Wilkes, San Jose, Calif.

[avagee]

meanwhile use your phone

While you are waiting for Kindle you could give http://www.booksinmyphone.com a try. They give away books that are packaged to be readable on regular 'dumb' cell phones. The screen size is fine for prose. You can browse and install direct to the phone from the mobile version of the site.