Linux Fu: The Local Phonebook

I’ll admit it: I miss the simplicity of /etc/hosts. There was something elegant about it. You wanted laserprinter to mean 192.168.1.40, so you opened a text file and wrote:

192.168.1.40 laserprinter

Done. No cloud account, no discovery daemon, no dashboard with material-themed icons. Just a name and an address. The trouble, of course, is that /etc/hosts is only simple when you have one machine. The moment you have a desktop, a laptop, a Raspberry Pi, a NAS, a test box, and a phone or two, every little network change becomes a tiny distributed-database problem. Which copy of /etc/hosts is authoritative? Did you update the laptop? What about the machine you only boot once a month?

One Solution

Modern LANs solved this with mDNS, using Avahi on Linux. It resolves addresses that end in .local. Instead of asking a central DNS server “who is thing.local?”, a machine sends a multicast query on the local network: “who has thing.local?” The device that owns the name answers. This is why your Linux box named spock and usually be reached as spock.local on your LAN.

There are limits. mDNS is link-local; it is meant for the local LAN, not the whole Internet and shouldn’t route across subnets. Each device is supposed to publish its own name. That works fine when the device cooperates. But what about devices that do not publish mDNS? Or little embedded things that barely even have an IP address?

That is where I wanted the best of both worlds: keep a small authoritative /etc/hosts file on one Linux box, but publish selected entries onto the LAN using mDNS.

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The Atari Jaguar Runs Linux

Among the many forgotten might-have-beens of the games console world, the Atari Jaguar occupies a special place. It was the final gasp of Atari Corporation, the Jack Tramiel-era incarnation of the famous pioneering game console brand that brought us the ST line of computers, and like Marlon Brando’s Terry Malloy character from On the Waterfront, it coulda been a contender. But the early ’90s games business wasn’t kind to the console from Sunnyvale, and it was squeezed from behind by the SNES and Genesis/MegaDrive, and in front from the PlayStation. Thirty years later then, can it run Linux? [Cakehonolulu] is here to show us how.

With only 2 megabytes of RAM and space for 8 megabytes of ROM, this is hardly a powerhouse. But its 16-bit 68000 processor is a supported Linux architecture, albeit with the -nommu flag on compilation. The “Jerry” DSP chip has the required serial port and timer to boot a first Linux kernel, and after a bit of hackery to make it jump to the ROM location, something boots. There’s no init process until the flat executable file for a -nommu kernel is navigated, but with that past a BusyBox userspace and a graphics driver for the “Tom” graphics chip gives it a chunky on-screen console. The code can be found in a GitHub repository, for the curious.

It seems to be the moment for 68k consoles to receive the Linux treatment, as it’s only a few weeks since we saw it on a MegaDrive. Other ’90s consoles aren’t far behind though, with the Nintendo 64 falling to the penguin a few years ago. Meanwhile, the Dreamcast had Linux running decades ago.


Jaguar image: Evan-Amos, Public domain.

Building A Wireless Fingerprint Authorization Device

Once upon a time, there was a bit of a fad for fingerprint authentication in laptops and desktop computers. It has long since faded, but [superdog] wanted just such a device for Linux and Mac machines. Thus, it was time to build one.

[superdog] designed the device, nicknamed immurok, as a tool for people who use external keyboards, and do lots of terminal work on Mac and Linux machines. Repeat password requests can interrupt one’s flow when hustling at the keys, so immurok was designed to ease this pain.

The device is based on a WCH CH592F microcontroller, which comes with Bluetooth connectivity out of the box. This allows immurok to connect wirelessly to the machine of your choice, advertising itself as a standard Bluetooth HID keyboard device. Fingerprint-wise, scanning is done with an R559S capacitive sensor, which verifies the match locally so there’s no transmitting biometric data anywhere. On the computer side, Linux is setup to use a CLI/TUI app plus PAM integration to handle authorization for system logins and sudo in the terminal. On the Mac platform, it’s used with a menu bar app, with PAM integration for admin prompts. There’s also a separate helper path for using it with the lock screen.

If you’re sick of entering your password all the time and wish unlocking your PC was more like unlocking your phone, this might be the project for you. We’ve seen similar projects before, too. If you’re whipping up fun gear for biometric auth, don’t hesitate to let us know on the tipsline.

It’s Linux, On A Sega Megadrive

If you were in the market for a games console in 1990, the chances are that the object of your desire was either a Super Nintendo with its 16-bit 6502 derivative, or the Sega Megadrive, sold as the Genesis in North America, with its Motorola 68000. Both machines featured impressive graphics and sound for their time, but they remain firmly in the 16-bit era. Which makes it a surprise to see LinuxMD. It’s Linux, for the Sega Megadrive, with the latest mainline kernel.

The Motorola 68000 series of chips was the first porting target for Linux, and is still maintained in 2026. This build runs from an SD card  in a modern Megadrive storage peripheral, and is reported to run on the original hardware. The lowly 68000 in the Sega doesn’t have a memory management unit required for the full Linux experience, so what’s really running here is a kernel compiled with the -nommu option. That in itself is a feat, on this architecture. On it you get smolutils, a cut down coreutils, and that seems to be it.

We like this project, for pushing both console and kernel to the limit, even though we see that maybe it’s not the most practical Linux machine. Meanwhile though, this isn’t the only UNIX-like OS for this console.


Image: Evan-Amos, Public domain.

Make That Smart TV Into A Computer

The smart TV is a fixture in most houses, variously an entertainment portal, corporate data gathering tool, or sometimes an outright spy. It’s a nice monitor with a computer built in, so can that computer be released to do something else? It’s a question [Xen’on] is answering, on an Android-based TV.

The guide is not too different from many others relating to Android phones, with a few quirks. An Android Debug Bridge (ADB) connection is established, root access is gained using Shizuku, and then it’s a case of installing a more conventional Linux front end with the Openbox window manager through Termux. There are some TV-specific things to do with handling power cycles, but the TV is now a usable Linux box.

It’s always good to see someone retrieve the Linux underneath a locked-down device, but the system spec tells the real story. By the looks of things this TV is a few years old as it had an Android version that’s a bit long in the tooth, and thus it also packs an aged version 4.x kernel. Couple that with a more seat-of-your-pants experience compared to a regular distro where many of the annoyances are taken care of, this isn’t an easy route to a trouble free desktop. Instead it has a lot of potential for making the TV what it was intend to be, an entertainment device. Merely one that gives much more software freedom.

Meanwhile, this isn’t the first Termux guide we’ve seen.

Running Modern Linux On A 68008

Linux developers have been trimming the fluff in recent years, removing support for older processors that hardly anyone uses with a modern kernel anymore. With that said, it’s possible to run the latest kernel on some truly old metal. As a case in point, [Colin Maykish] just got it going on a Motorola 68008!

The rig in question is a Mackerel-68k—a homebrew single-board computer built around Motorola’s famous 68000 CPU line. This version in particular is running a 68008 rated at 8 MHz, though it’s overclocked to 14 MHz for a little more pep, and has just 3.5 MB of RAM. Despite these limitations, the board can run the mainline v7.1-rc6 kernel, booting into userspace and providing a very minimalistic BusyBox shell. Booting is slow, and doing much more than that is impossible without running out of RAM, but it’s an impressive feat nonetheless. [Colin] has also had the 68010 and 68030 chips running the kernel, too.

We’ve previously discussed efforts to bring Linux into the future while leaving old chips behind. Video after the break.

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Linux Fu: Fake Webcams, GUI Edition

Previously, I looked at using the Linux video loopback system from the command line. The basic trick was simple enough: capture video from a real camera, process it with something like ffmpeg, and write the result to a fake camera device via the v4l2loopback device. Then a browser, or any camera-enabled software, sees the fake camera as if it were real. This allows you to manipulate video before sending it to the rest of the world.

That works, and for those of us who like command lines, it’s easy enough to execute. But not everyone loves the command line. In the comments, there was another obvious answer: use OBS Studio.

While OBS is excellent, it is also a bit like using a laser to chop a carrot. If you already use OBS, fine. If you only want to crop a webcam, add an effect, mirror an image, or feed a virtual camera, it can feel like a lot. If you must have a GUI, you can try Webcamoid, which sits somewhere between a simple webcam viewer and a full video production system.

Webcamoid gives you a GUI for selecting a camera, applying effects, and sending the result to a virtual camera. Conceptually, it is much closer to the command-line loopback setup from the previous post than to OBS. You are still building a pipeline from input camera to output camera, but now you can do much of it with buttons and menus instead of shell commands.

That’s in theory, of course. Implementing Webcamoid turned out to be quite the exercise. Granted, this probably varies depending on where you install software. If your distro has a clean working copy of Webcamoid and its dependencies, good for you. For everyone else, keep reading.

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