Somehow, seeing DOOM on things that were never meant to run DOOM never gets old. It’s probably hard to get further into the “never meant to run DOOM” weeds than a coffee maker, but [Robin M.] has done it, and tells you exactly how in his excellent write-up. It adds a new dimension to hard mode — try and play while you’re waiting for your morning coffee.
Of course [Robin] doesn’t start with just any coffee machine; most sensible percolators won’t have any silicon capable of executing code, much less gaming on. The Spengler PSL50 machine [Robin] is hacking is a smart device with a Linux computer inside, although in this case there’s a point to having the smarts, as it’s meant to be a self-serve, pay-to-drink coffee kiosk. Handling payments and the touchscreen menus seems like justification enough for a microprocessor.
As you might expect, all the ‘smarts’ of this coffee maker are on the touchscreen module which aside from the brains of the operation — i.MX 6 ARM Cortex A9 processor — happens to have a handy a debug port. With just a little probing to find the right pins, he gets a console connection via that debug port to the 2013-era Linux build that runs the device, and then it’s off to the races. To make life even easier for [Robin], there was no uboot password set, nor any protections. So a simple setnv gets him into an sh prompt, and then he’s set. As for DOOM, he’s using fbDOOM, a version that renders directly to the framebuffer, and compiles it as a self-contained binary so he doesn’t have to care that everything on the Linux system is 13 years out of date.
Spengler made hacking this device relatively easy with their almost complete lack of security, and the resulting project is well documented, well executed, and tickles our funny bones the same way seeing DOOM on a toaster did. We haven’t covered DOOM on a refrigerator but it’s only a matter of time before the whole kitchen is killing demons, including the thermostat in the hall.
