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Graphics: VGA Signal In A Browser Window, Mesa's Radeon R600 Gallium3D Driver, EGL+OpenGL Off-screen Multi-Card

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  • VGA Signal In A Browser Window, Thanks To Reverse Engineering

    [Ben Cox] found some interesting USB devices on eBay. The Epiphan VGA2USB LR accepts VGA video on one end and presents it as a USB webcam-like video signal on the other. Never have to haul a VGA monitor out again? Sounds good to us! The devices are old and abandoned hardware, but they do claim Linux support, so one BUY button mash later and [Ben] was waiting patiently for them in the mail.

    But when they did arrive, the devices didn’t enumerate as a USB UVC video device as expected. The vendor has a custom driver, support for which ended in Linux 4.9 — meaning none of [Ben]’s machines would run it. By now [Ben] was curious about how all this worked and began digging, aiming to create a userspace driver for the device. He was successful, and with his usual detail [Ben] explains not only the process he followed to troubleshoot the problem but also how these devices (and his driver) work. Skip to the end of the project page for the summary, but the whole thing is worth a read.

  • Mesa's Radeon R600 Gallium3D Driver Now Has NIR Support Under Review

    Similar to the trend with other Mesa drivers, the Radeon R600g driver for supporting Radeon HD 2000 through Radeon HD 6000 series graphics cards has been seeing experimental work to introduce a NIR back-end for this modern intermediate representation. That R600 NIR support now has a merge request open meaning it could possibly land still for Mesa 20.0.

    The R600g NIR support has been worked on by Gert Wollny and currently targets Radeon HD 5000 "Evergreen" graphics cards with support for other AMD GPU generations handled by this Gallium3D driver not yet supported. Additionally, this NIR back-end only supports vertex / fragment / geometry shaders for now and other features missing.

  • Playing with EGL+OpenGL Off-screen Multi-Card

    So I've now spent the last day and a half playing with getting EGL offscreen rendering working on Linux. There are two major ways to do off-screen rendering with EGL and OpenGL. In the first, you use a pbuffer surface, that surface is basically a purpose-defined surface-type for off-screen backing of a renderer. When I use the EGL enumeration API we always seem to get pbuffer compatible visuals (and *not* window compatible ones).

    On Ubuntu 18.04 the enumeration API seems to be... problematic, lots of segfaults, particularly with the VirtualBox driver that shows up in the enumerations. On Ubuntu 19.10 the behaviour is much more reliable, with all 3 GPUs in my prime-based nVidia/Intel laptop (including the VirtualBox GPU) completing the OpenGL query for version, extensions, etc. The missing bit is being able to specify which GPU to use, as the EGL query API doesn't seem to have a way to get a "name" that a user would recognise to describe the card.

More in Tux Machines

today's howtos

Home Assistant improves performance in 0.112 release

The Home Assistant project has released version 0.112 of the open-source home automation hub we have previously covered, which is the eighth release of the project this year. While previous releases have largely focused on new integrations and enhancements to the front-end interface, in this release the focus has shifted more toward improving the performance of the database. It is important to be aware that there are significant database changes and multiple potential backward compatibility breaks to understand before attempting an upgrade to take advantage of the improvements. According to the release notes written by contributor Franck Nijhof, better performance has been a major goal of this release with a focus on both the logbook and history components. This builds on the work of the previous release (v0.111) from a performance perspective, which focused on reducing the time it takes to initialize the hub at startup. Read more

Android Leftovers

today's programming leftovers and licence lawsuit

  • Whiteboard Coding Stress Reduces Performance by More than Half

    A recent study by North Carolina State University researchers found that stress caused by whiteboard technical interviews significantly affected the performance of job candidates. Whiteboard tests are a common feature of the hiring process for software developers. During these sessions, candidates are expected to develop coding solutions on a whiteboard while describing their decision-making process to observers. In the study, half of the participants performed the typical whiteboard test with an interviewer looking on. The other half solved the problem on a whiteboard in a private room with no interviewer present. The private interviews also included a retrospective “think-aloud” session to discuss the solutions presented. [...] In the paper, the researchers noted that “a technical interview has an uncanny resemblance to the Trier social stress test,” a technique used by psychologists with the sole purpose of inducing stress. “Through a happy accident, the software industry has seemingly reinvented a crude yet effective instrument for reliably introducing stress in subjects, which typically manifests as performance anxiety,” they said. Additionally, “the unique combination of cognitive-demanding tasks with a social-evaluative threat (essentially being watched) is consistent and powerful,” they stated.

  • Address Sanitizer, Part 1

    Hello everyone. My name is Harshit Sharma (hst on IRC). I am working on the project to add the “Address Sanitizer” feature to coreboot as a part of GSoC 2020. Werner Zeh is my mentor for this project and I’d like to thank him for his constant support and valuable suggestions. It’s been a fun couple of weeks since I started working on this project. Though I found the initial few weeks quite challenging, I am glad that I was able to go past that and learned some amazing stuff I’d cherish for a long time. Also, being a student, I find it incredible to have got a chance to work with and learn from such passionate, knowledgeable, and helpful people who are always available over IRC to assist. [...] The design of ASan in coreboot is based on its implementation in Linux kernel, also known as Kernel Address Sanitizer (KASAN). However, coreboot differs a lot from Linux kernel due to multiple stages and that is what poses a challenge.

  • Etcd, or, why modern software makes me sad

    I talk a lot of shit about Google, but Facebook and Microsoft are nearly as bad at turning out legions of ex-employees who can't be left alone in the room with a keyboard lest they attempt to recreate their previous employer's technology stack, poorly.

  • EuroPython 2020: Find a new job at the conference

    Our sponsors would love to get in touch with you, so please have a look and visit them at their sponsor exhibit channel on Discord or contact them via the links and email addresses given on the page.

  • Check if incoming edges in a vertex of directed graph is equal to vertex itself or not

    Given a directed Graph G(V, E) with V vertices and E edges, the task is to check that for all vertices of the given graph, the incoming edges in a vertex is equal to the vertex itself or not.

  • Jelurida Files Lawsuit Against Apollo Blockchain For License Violations Over Nxt Code