Collaborate Disseminate
In the vast majority of cases, running a Linux-based operating system involves a pretty powerful processor with a lot of memory on hand, and perhaps most importantly, a memory management …read more Continue reading Tiny Linux on a No-MMU RISC-V Microcontroller
It’s something of an article of faith, that to run Linux your computer must include a hardware memory management unit, or MMU. To an extent it’s true, in that for …read more Continue reading A Tiny RISC-V Emulator Runs Linux With No MMU. And Yes, It Runs DOOM!
As long as 3D printers have been around, it seems as though many of us have dreamed about nozzle-sharing solutions for multicolor 3D prints. Just because Prusa’s MMU has had …read more Continue reading Enraged Rabbit Project is a Filament Cocktail Special
3D printed lithophanes are great, if a bit monochromatic. [Thomas Brooks] (with help from [Jason Prius]) changed all that with a tool for creating color lithophanes but there’s a catch: you’ll need a printer capable of creating multi-color prints to do it.
A video (embedded below) begins with an intro …read more
Continue reading Lithophanes Ditch the Monochrome with a Color Layer
[Nop head] discovered that cheap multimeter leads costing only a few bucks can come with more than one may have bargained for. The first set had a large amount of useful-looking attachments, but the wires used for the leads were steel with a resistance of about one ohm each. With two leads in use, that means any resistance measurement gets two ohms added for free. More seriously, when measuring current, the wires can heat up rapidly. Voltage measurements would be affected the least, but the attachments and lead design expose a large amount of bare metal, which invites accidental shorts …read more
Continue reading Cheap Multimeter Leads Come With Extra Ohms, Free!
Here’s something really wonderful. [Dave Akerman] wrote up the results of his attempt to use a high-altitude balloon to try to re-create a famous image of NASA’s Bruce McCandless floating freely in space with the Earth in the background. [Dave] did this in celebration of the 34th anniversary of the first untethered spacewalk, even going so far as to launch on the same day as the original event in 1984. He had excellent results, with plenty of video and images recorded by his payload.
Adhering to the actual day of the spacewalk wasn’t the only hurdle [Dave] jumped to make …read more
Continue reading Plastic Model Emulates the First Untethered Spacewalk
The year so far has been filled with news of Spectre and Meltdown. These exploits take advantage of features like speculative execution, and memory access timing. What they have in common is the fact that all modern processors use cache to access memory faster. We’ve all heard of cache, but what exactly is it, and how does it allow our computers to run faster?
In the simplest terms, cache is a fast memory. Computers have two storage systems: primary storage (RAM) and secondary storage (Hard Disk, SSD). From the processor’s point of view, loading data or instructions from RAM is …read more
Researchers from VUSec found a way to break ASLR via an MMU sidechannel attack that even works in JavaScript. Does this matter? Yes, it matters. A lot. The discovery of this security flaw along with the practical implementation is really important mainly because of two factors: what it means for ASLR to be broken and how the MMU sidechannel attack works inside the processor.
Address Space Layout Randomization or ASLR is an important defense mechanism that can mitigate known and, most importantly, unknown security flaws. ASLR makes it harder for a malicious program to compromise a system by, as the …read more
Continue reading ASLR^CACHE Attack Defeats Address Space Layout Randomization