Close To The Metal

October 14, 2023 by Elliot Williams 81 Comments

Firmware is caught between hardware and software. What do I mean? Microcontroller designers compete on how many interesting and useful hardware peripherals they can add to the chips, and they are all different on purpose. Meanwhile, software designers want to abstract away from the intricacies and idiosyncrasies of the hardware peripherals, because code wants to be generic and portable. Software and hardware designers are Montagues and Capulets, and we’re caught in the crossfire.

I’m in the middle of a design that takes advantage of perhaps one of the most idiosyncratic microcontroller peripherals out there – the RP2040’s PIOs. Combining these with the chip’s direct memory access (DMA) controllers allows some fairly high-bandwidth processing, without bogging down the CPUs. But because I want this code to be usable and extensible by a wide audience, I’m also trying to write it in MicroPython. And configuring DMA controllers is just too idiosyncratic for MicroPython.

But there’s an escape hatch. In my case, it’s courtesy of the machine.mem32 function, which lets you read and write directly into the chip’s memory, including all of the memory-mapped configuration registers. Sure, it’s absurdly low-level, but it means that anything you read about in the chip’s datasheet, you can do right away, and from within the relative comfort of a Micropython program. Other languages have their PEEK and POKE equivalents as well, or allow inline assembler, or otherwise furnish you the tools to get closer to the metal without having to write all the rest of your code low level.

I’m honestly usually a straight-C or even Forth programmer, but this experience of using a higher-level language and simultaneously being able to dive down to the lowest levels of bit-twiddling at the same time has been a revelation. If you’re just using Micropython, open up your chip’s datasheet and see what it can offer you. Or if you’re programming at the configure-this-register level, check out the extra benefits you can get from a higher-level language. You can have your cake and eat it too!

Hackaday Podcast Ep 240: An Amazing 3D Printer, A Look Inside Raspberry Pi 5, And Cameras, Both Film And Digital

October 13, 2023 by Dan Maloney 6 Comments

Date notwithstanding, it’s your lucky day as Elliot and Dan get together to review the best hacks of the week. For some reason, film photography was much on our writers’ minds this week, as we talked about ways to digitalize an old SLR, and how potatoes can be used to develop film (is there a Monty Python joke in there?) We looked at a 3D printer design that really pulls our strings, the custom insides of the Raspberry Pi 5, and the ins and outs of both ferroresonant transformers and ham radio antennas. Learn about the SMD capacitor menagerie, build a hydrogen generator that probably won’t blow up, and listen to the differences between a mess of microphones. And that’s not all; the KIM-1 rides again, this time with disk drive support, Jenny tests out Serenity but with ulterior motives, and Kristina goes postal with a deep dive into ZIP codes.

Check out the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Grab a copy for yourself if you want to listen offline.

Continue reading “Hackaday Podcast Ep 240: An Amazing 3D Printer, A Look Inside Raspberry Pi 5, And Cameras, Both Film And Digital” →

This Week In Security: Curl Reveal, Rapid Reset DDoS, And Libcue

October 13, 2023 by Jonathan Bennett 17 Comments

Curl gave us all a big warning that a severe security problem had been found in that code-base. Given the staggering number of Curl installs around the world, we held our collective breath and waited for the bombshell to drop this Wednesday. It turns out, it’s not quite as bad as feared — so long as you don’t have a SOCKS proxy.

In hindsight, shipping a heap overflow in code installed in over twenty billion instances is not an experience I would recommend. — Daniel Stenberg

The trouble started when the SOCKS5 proxy support was converted to a non-blocking implementation. It’s a win for libcurl to work on requests asynchronously, but refactoring code and new features always runs a bit of risk. SOCKS5 proxying has some quirks, like allowing DNS resolution to happen locally or at the proxy. The new async code starts out with:

bool socks5_resolve_local = (proxytype == CURLPROXY_SOCKS5) ? TRUE : FALSE;

First off, unnecessary ternary is unnecessary. But note that this local variable gets set by the proxytype. If that’s CURLPROXY_SOCKS5_HOSTNAME, then it uses remote resolution. But inherited from old code is a check for a hostname that is too long for a SOCKS request (255 bytes). This code converts back to local resolution in this case.

The important detail here is that this function is now a state machine, that potentially runs multiple times for a single request, to achieve that asynchronous execution. The check for a too-long hostname only happens during the initialization state. Copying the hostname into the buffer happens in a different state. If setting up the connection takes enough time, the function will return and be executed again when something has changed. The ternary check runs again, but not the hostname-too-long. So if set to do remote resolution with a long enough host name, execution slips through this edge case, and the long hostname is copied into a too-small buffer.

It’s safe to assume that this heap overflow can result in arbitrary code execution. The fix has landed in 8.4.0, after being present for 1,315 days. [Daniel] goes ahead and gets ahead of the inevitable suggestion that Curl should be written in rust or another memory-safe language. Curl was started before those alternatives existed, and there is a very slow effort to move portions of the project to memory-safe languages. And you’re welcome to help out. Continue reading “This Week In Security: Curl Reveal, Rapid Reset DDoS, And Libcue” →

Hackaday Superconference 2023: Workshops Announced, Get Tickets Now!

October 12, 2023 by Elliot Williams 4 Comments

Last week, we announced just half of our fantastic slate of talks for Supercon. This week, we’re opening up the workshops. The workshops are small, hands-on opportunities to build something or learn something, lead by an expert in the field. Workshops sell out fast, so register now if you’re interested.

And stay tuned for the next round of talk reveals next week! And maybe even the badge reveal?

Andy Geppert
Weave Your Own Core Memory – Core16!

This workshop provides you with the opportunity to weave your own core memory! Using 16 authentic ferrite core bits and 16 RGB LEDs, you can play tic-tac-toe, paint with a magnetic stylus, and create your own interactive experiences. Andy Geppert will guide you through the assembly of Core16. The Core16 kit is the little brother of the Core64 kit. The smaller Core16 kit reduces assembly time/cost, enabling more people to experience the challenge and satisfaction of creating their own core memory.

Travis Foss
Presented by DigiKey: Introduction and expansion of the XRP Robotics Platform

In this workshop you will be able to get your hands on the new XRP (Experiential Robotics Platform) and take the basics a step further with a few additional parts. Along with the base kit, participants will have the opportunity to install a RGB twist encoder, a LCD screen, and a buzzer to create a setup that will allow the user to choose a program onboard without being tethered to a computer.

Becky Button
How to Make a Custom Guitar Pedal

Musical effects are for everybody! Join this workshop and get hands-on experience assembling and programming your musical effects pedals. Walk away from this workshop with the capability of integrating multiple musical effects into 1 device and reprogramming the pedal with any effects you want!

Daniel Lindmark
From Zero to Git: 1 Hour Hardware Git Bootcamp

In this workshop, you will learn all about basic git operations, including how to download and install the client, setting up a repo, synching changes, and much more. Learn how to navigate common issues and take advantage of a live FAQ during the workshop.

Jazmin Hernandez
Solder and Learn How to Use Your Own Anti-Skimmer (HunterCat)

Have you ever been vulnerable to data theft? Do you fear using your bank card in ATMs or even in a restaurant? Protect your information from potential skimmers in this workshop while you learn to solder some components of your anti-skimmer/magnetic stripe clone detectors. By the end of the workshop, you’ll have a device to insert before using your bank card to check for potential issues.

Matt Venn
Tiny Tapeout – Demystifying Microchip Design and Manufacture

In this workshop, you can design and manufacture your own chip on an ASIC. You will learn the basics of digital logic, how semiconductors are made, the skills needed to use an online digital design tool for simulation, and how to create the GDS file for manufacturing. Participants will also have the option to submit their designs to be manufactured as part of the Tiny Tapeout project.

You can’t attend the workshops without attending Supercon, so get your tickets! (As we write, there are only ten more…)

Tech In Plain Sight: Skyscrapers

October 11, 2023 by Al Williams 3 Comments

It is hard to imagine that for thousands of years, the Great Pyramid of Giza was the tallest manmade structure in the world. However, like the Lincoln Cathedral and the Washington Monument, which also held that title, these don’t count as skyscrapers because they didn’t provide living or working space to people. But aside from providing living, retail, or office space, skyscrapers also share a common feature that explains why they are even possible: steel frame construction.

Have you ever wondered why pyramids appear in so many ancient civilizations? The answer is engineering. You build something. Then, you build something on top of it. Then you repeat. It just makes sense. But each upper layer adds weight to all the lower layers, so you must keep getting smaller. Building a 381-meter skyscraper like the Empire State Building using self-supporting walls would mean the ground floor walls would be massive. Steel lets you get around this.

In Antiquity

You might think of high-rise buildings as a modern thing, but that’s actually not true. People seem to have built up to the best of their abilities for a very long time. Some Roman structures were as high as ten stories. Romans built so high that Augustus even tried to limit building height to 25 meters — probably after some accidents. In the 12th century, Bologna had as many as 100 towers, one nearly 100 meters tall.

There are many other examples, including mudbrick structures rising 30 meters in Yemen and 11th-century Egyptian structures rising 14 stories. In some cases, building up was due to the cost or availability of property. In others, it was to stay inside a defensive wall. But whatever the reason, self-supporting walls can only go so high before they are impractical.

So steel and iron frames grabbed the public’s attention with things like Joseph Paxton’s Crystal Palace in 1851, and Gustav Eiffel’s Tower in 1887.

Continue reading “Tech In Plain Sight: Skyscrapers” →

Jenny’s Daily Drivers: SerenityOS, And In Particular, Ladybird

October 10, 2023 by Jenny List 36 Comments

As we continue on with the series in which I take a different OS for a spin every month I am afraid, dear reader, that this month I have a confession to make. Our subject here isn’t a Daily Driver at all, and it’s not the fault of the operating system in question. Instead I’m taking a look at a subject that’s not quite ready for the big time but is interesting for another reason. The OS is SerenityOS, which describes itself as “a love letter to ’90s user interfaces with a custom Unix-like core“, and the reason I’m interested in it comes from its web browser. I know that the OS is very much a work in progress and I’ll have to forgo my usual real hardware and run it in QEMU, but I’ve heard good things about it and I want to try it. The browser in question is called Ladybird, and it’s interesting because it has the aim of creating a modern fully capable cross-platform browser from scratch, rather than being yet another WebKit-based appliance.

A Pleasant Trip Into The 1990s

Part of a Linux desktop with the SerenityOS build instructions in the background, a terminal having built the OS, and the OS itself in a QEMU window. — My first look at SerenityOS after building it.

SerenityOS isn’t ready to be installed on real hardware, and there’s no handy ISO to download. Instead I had to clone the repository to my Linux machine and run the build script to compile the whole thing, something I was very pleased to observe only took about 40 minutes. It creates a hard disk image and opens QEMU for you, and you’re straight into a desktop.

When they mention ’90s user interfaces they definitely weren’t hiding anything, because what I found myself in could have easily been a Windows 9x desktop from the middle of that decade. There are a bunch of themes including some Mac-like ones, but should you select the “Redmond” one, you’re on very familiar ground if you had a Microsoft environment back then. It’s only skin-deep though, because as soon as you venture into a command line shell there’s no DOS to be found. This is a UNIX-like operating system, so backslashes are not allowed and it’s familiarly similar to an equivalent on my Linux box. The purpose of this review is not to dive too far into the workings of the OS, but suffice it to say that both the underpinnings and the desktop feel stable and as polished as a Windows 95 lookalike can be. The various bundled utilities and other small programs seem to work well, and without any hint of the instabilities I’ve become used to when I’ve experimented with other esoteric operating systems. Continue reading “Jenny’s Daily Drivers: SerenityOS, And In Particular, Ladybird” →

Illustrated Kristina with an IBM Model M keyboard floating between her hands.

Keebin’ With Kristina: The One With The Arboreal Keyboards

October 9, 2023 by Kristina Panos 6 Comments

Well, unfortunately we don’t know much yet about this nice wooden keyboard from [Kelvin Chow], but maybe this inclusion will encourage [Kelvin] to post more about it.

Sure is nice-looking, don’t you think? That’s because there some great details at play here, like the legend-less two-tone keycaps and the neat-o locking box it sits in.

This keyboard is inspired by the Hacoa Ki-board, which uses a singles plank of wood to craft the keycaps. [Kelvin] wanted to try this technique for themselves. Evidently this won’t be the last wooden keyboard, so stay tuned for more over on Hackaday.io.

This isn’t the first dead-tree keyboard we’ve seen around here, either. A while back we saw one with Scrabble tile keycaps, and earlier this year, a nice wooden macro pad.

Continue reading “Keebin’ With Kristina: The One With The Arboreal Keyboards” →