Linux Hacks

497 Articles

SuSE Take On Red Hat, Forking RHEL

July 12, 2023 by 18 Comments

One of the Linux stories of the moment has come from Red Hat, with their ongoing efforts to make accessing the source of their Red Hat Enterprise Linux product a paid-for only process. This has caused consternation and annoyance alike, from the open source community angry at any liberties taken with the GPL, and from the community of RHEL users and customers concerned as to what it might mean for them.

Now a new player has entered the fray in the form of SuSe, who have announced the creation of an RHEL fork with the intention of maintaining a freely-available Red Hat compatible operating system distribution.

This is good news for all who use Red Hat derived software and we expect the likes of Rocky Linux will be taking a close look at it, but it’s also a canny move from the European company as they no doubt hope to tempt away some of those commercial Red Hat customers with a promise of stability and their existing experience supporting Red Hat users through their mixed Linux support packages. We hope they’ll continue to maintain their relationship with the open source world, and that the prospect of their actions unleashing a new commercial challenge causes Red Hat to move away from the brink a little.

Need some of the backstory? We’ve got you covered.

The perfect header for this story comes via atzerok, CC BY-SA 2.0.

Linux Device Drivers In Only A Few Years

July 11, 2023 by 10 Comments

[Johannes 4GNU_Linux] has been filming a video series on how to write Linux device drivers for a couple of years now, but luckily, you won’t need that long to watch them or to create your own driver. He’s added some recent videos to the series, like the one below, but might want to rewind a few years and start at the beginning.

If you build your own hardware for Linux, you’ll probably eventually want to write a driver which runs as a privileged program. While there are many things you can do in user space, for the ultimate control and performance, you can’t beat a driver.

One problem, though, is that drivers can really crash your system in a big way. In the old days, it was common to have a dedicated system for driver development. Today, for many drivers, you can get away with running a virtual machine that you can crash and reload without much trouble.

The videos cover diverse topics like interrupts, completions, polling, and threads. He even uses a Raspberry Pi, which will be very useful for many embedded projects. Of course, the trend these days is to have one driver — like the USB driver — and have it provide user-space access so that everyone doesn’t have to write their own drivers. But, as usual, that only goes so far.

We aren’t sure how many more videos there will be, but if you make it through the first 31, maybe more will be waiting for you. It has been a while since we looked at SPI drivers in Linux. As an example of why you might want to roll your own, consider a custom FPGA driver.

Continue reading “Linux Device Drivers In Only A Few Years” →

Rocky Strikes Back At Red Hat

June 30, 2023 by 56 Comments

The world of Linux has seen some disquiet over recent weeks following the decision of Red Hat to restrict source code distribution for Red Hat Enterprise Linux (RHEL) to only their paying customers. We’re sure that there will be plenty of fall-out to come from this news, but what can be done if your project relies upon access to those Red Hat sources?

The Red-Hat-derived Rocky Linux distro relies on access to RHEL source, so the news could have been something of a disaster. Fortunately for Rocky users though, they appear to have found a reliable way to bypass the restriction and retain access to those RHEL sources. Red Hat would like anyone wanting source access to pay them handsomely for the privilege, but the Rocky folks have spotted a way to bypass this. Using readily available cloud images they can spin up a RHEL system and use it to download their sources, and they can do this as an automated process.

We covered this story as it unfolded last week, and it seemed inevitable then that something of this nature would be found, as for all Red Hat’s wishes a GPL-licensed piece of code can’t be prevented from being shared. So Rocky users and the wider community will for now retain access to the code, but will Red Hat strike back? It’s inevitable that there will be a further backlash from the community against any such moves, but will Red Hat be foolhardy enough to further damage their standing in this regard? They’re certainly not the only large distro losing touch with their users.

Et Tu, Red Hat?

June 23, 2023 by 94 Comments

Something odd happened to git.centos.org last week. That’s the repository where Red Hat has traditionally published the source code to everything that’s a part of Red Hat Enterprise Linux (RHEL) to fulfill the requirements of the GPL license. Last week, those packages just stopped flowing. Updates weren’t being published. And finally, Red Hat has published a clear answer to why:

Red Hat has decided to continue to use the Customer Portal to share source code with our partners and customers, while treating CentOS Stream as the venue for collaboration with the community.

Sounds innocuous, but what’s really going on here? Let’s have a look at the Red Hat family: RHEL, CentOS, and Fedora.

RHEL is the enterprise Linux distribution that is Red Hat’s bread and butter. Fedora is RHEL’s upstream distribution, where changes happen fast and things occasionally break. CentOS started off as a community repackaging of RHEL, as allowed under the GPL and other Open Source licenses, for people who liked the stability but didn’t need the software support that you’re paying for when you buy RHEL.

Red Hat took over the reigns of CentOS back in 2014, and then imposed the transition to CentOS Stream in 2020, to some consternation. This placed CentOS Stream between the upstream Fedora, and the downstream RHEL. Some people missed the stability of the old CentOS, and in response a handful of efforts spun up to fill the gap, like Alma Linux and Rocky Linux. These projects took the source from git.centos.org, and rebuilt them into usable community operating systems, staying closer to RHEL in the process.

Red Hat has published a longer statement elaborating on the growth of CentOS Stream, but it ends with an interesting statement: “Red Hat customers and partners can access RHEL sources via the customer and partner portals, in accordance with their subscription agreement.” What exactly is in that subscription agreement? Well according to Alma Linux, “the way we understand it today, Red Hat’s user interface agreements indicate that re-publishing sources acquired through the customer portal would be a violation of those agreements.” Continue reading “Et Tu, Red Hat?” →

Linux Fu: Easy And Easier Virtual Networking

June 14, 2023 by 15 Comments

One of the best things about Linux is that there are always multiple ways to do anything you want to do. However, some ways are easier than others. Take, for example, virtual networking. There are plenty of ways to make a bunch of Internet-connected computers appear to be on a single private network. That’s nothing new, of course. Linux and Unix have robust networking stacks. Since 2018, though, Wireguard has been the go-to solution; it has a modern architecture, secure cryptography, and good performance.

There’s only one problem: it is relatively difficult to set up. Not impossible, of course. But it is a bit difficult, depending on what you want to accomplish.

How Difficult?

You must set up a wireguard server and one or more clients. You’ll need to pick a range of IP addresses. You might need to turn on routing. You have to generate keys. You might need to configure DNS and other routing options. You’ll certainly need to modify firewall rules. You’ll also need to distribute keys.

None of these steps are terribly difficult, but it is a lot to keep straight. The wg program and wg-quick script do most of the work, but you have a lot of decisions and configuration management to keep straight.

Browse the official “quick start,” and you’ll see that it isn’t all that quick. The wg-quick script is better but only handles some use cases. If you want really limited use cases, there are third-party tools to do a lot of the rote work, but if you need to change anything, you’ll still need to figure it all out.

That being said, once you have it set up, it pretty much works without issue and works well. But that initial setup can be very frustrating. Continue reading “Linux Fu: Easy And Easier Virtual Networking” →

Hyundai Is Doomed: Porting The 1993 Classic To A Hyundai Head Unit

June 11, 2023 by 6 Comments

In the natural order of the world, porting DOOM to any newly unlocked computing system is an absolute given. This a rule which [greenluigi1] understands all too well, leading to presumably the first Hyundai to be equipped with this all-time classic on its infotainment system. This follows hot on the trail of re-hacking said infotainment system and a gaggle of basic apps being developed for and run on said head unit (being the part of the infotainment system on the front dashboard). Although it is a Linux-based system, this doesn’t mean that you can just recompile DOOM for it, mostly because of the rather proprietary system environment.

To make life easy, [greenluigi1] picked doomgeneric as the version to port. The main selling point of this project is that it only requires the developer to implement five functions to support a new platform, which then ‘just’ left figuring out how to do this on a head unit. Two of these (DG_SleepMs() and DG_GetTicksMS()) could be copied verbatim from the X11/xlib port, but the remaining three required a bit of sleuthing.

Where things go sideways is with keeping the head unit’s Helix window manager happy, and stick to the limited ways a GUI application can be launched, including the way arguments are passed. For the PoC, it was decided to just hardcode these arguments and only register the game with Helix using an .appconf configuration file. When it came to drawing pretty graphics on the screen, this was decidedly easier since the system uses Qt5 and thus offers the usual ways to draw to a QPixmap, which in this case maps to the framebuffer.

After a few playful sessions with the head unit’s watchdog timer, [greenluigi1] found himself staring at a blank screen, despite everything appearing to work. This turned out to be due to the alpha channel value of 0 that was being set by default, along with the need for an explicit refresh of the QPixmap. Up popped DOOM, which left just the implementation of the controls.

In order to start the game, you have to literally buckle up, and the steering wheel plus media control buttons are your inputs, which makes for a creative way to play, and perhaps wear some bald spots onto your tires if you’re not careful. If you’d like to give it a shot on your own ride, you can get the project files on GitHub.

Continue reading “Hyundai Is Doomed: Porting The 1993 Classic To A Hyundai Head Unit” →

Bye Bye Ubuntu, Hello Manjaro. How Did We Get Here?

June 8, 2023 by 116 Comments

Last week I penned a cheesy fake relationship breakup letter to Ubuntu, my Linux distribution of choice for the last 15 years or so. It had well and truly delivered on its promise of a painless Linux desktop for most of that time, but the most recent upgrades had rendered it slow and bloated, with applications taking minutes to load and USB peripherals such as my film scanner mysteriously stopping working. I don’t have to look far to identify the point at which they adopted Snap packages as the moment when it all went wrong. I’d reached the point at which I knew our ways must part, and it was time to look for another distro.

Continue reading “Bye Bye Ubuntu, Hello Manjaro. How Did We Get Here?” →