pudc - A PID 1 process that barks to the internet by mssola

Description

As a fun exercise in order to dig deeper into the Linux kernel, its interfaces, the RISC-V architecture, and all the dragons in between; I'm building a blog site cooked like this:

• The backend is written in a mixture of C and RISC-V assembly.
• The backend is actually PID1 (for real, not within a container).
• We poll and parse incoming HTTP requests ourselves.
• The frontend is a mere HTML page with htmx.

The project is meant to be Linux-specific, so I'm going to use io_uring, pidfs, namespaces, and Linux-specific features in order to drive all of this.

I'm open for suggestions and so on, but this is meant to be a solo project, as this is more of a learning exercise for me than anything else.

Goals

• Have a better understanding of different Linux features from user space down to the kernel internals.
• Most importantly: have fun.

Resources

• https://github.com/mssola/pudc

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Create openSUSE images for Arm and RISC-V boards by avicenzi

Project Description

Create openSUSE images (or test generic EFI images) for Arm and RISC-V boards that are not yet supported.

Goal for Hackweek

Create bootable images of Tumbleweed for SBCs that currently have no images available or are untested.

Consider generic EFI images where possible, as some boards can hold a bootloader.

Document in the openSUSE Wiki how to flash and use the image for a given board.

Hack Week 25

• Raspberry Pi 5
• Lichee RV
• Milk-V Jupiter
• SiFive HiFive Premier P550
• SiFive HiFive Unmatched Rev B

Hack Week 24

Hack Week 23

• SiFive HiFive Unmatched

Hack Week 22

• NanoPC T4

Hack Week 21

• NanoPi M4B
• Radxa Zero

Resources

• openSUSE Arm Portal
• openSUSE RISC-V Portal
• SiFive Development Boards
• Raspberry Pi 5

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Reassess HiFive Premier P550 board (for RISC-V virtualization) by a_faerber

Description

With growing interest in the RISC-V instruction set architecture, we need to re-evaluate ways of building packages for it:

Currently openSUSE OBS is using x86_64 build workers, using QEMU userspace-level (syscall) emulation inside KVM VMs. Occasionally this setup causes build failures, due to timing differences or incomplete emulation. Andreas Schwab and others have collected workarounds in projects like openSUSE:Factory:RISCV to deal with some of those issues.

Ideally we would be using native riscv64 KVM VMs instead. This requires CPUs with the H extension. Two generally available development boards feature the ESWIN 7700X System-on-Chip with SiFive P550 CPUs, HiFive Premier P550 and Milk-V Megrez. We've had access to the HiFive Premier P550 for some time now, but the early version (based on Yocto) had issues with the bootloader, and reportedly later boards were booting to a dracut emergency shell for lack of block device drivers.

Goals

• Update the boot firmware
• Test whether and how far openSUSE Tumbleweed boots

Results

• Boot firmware image 2025.11.00 successfully flashed onto board
  • Enables UEFI boot in U-Boot by default
  • U-Boot's embedded Flat Device Tree is lacking a timebase-frequency, required for recent (6.16.3) mainline kernels (panic leading to reset, visible via earlycon=sbi)
• Tested eswin/eic7700-hifive-premier-p550.dtb from Ubuntu 2025.11.00 image
  • Allows to boot past the above panic, but times out in JeOS image while waiting for block device, dropping to dracut emergency shell
  • No devices shown in lsblk -- 6.16 appears to be lacking device drivers still

Resources

• SiFive HiFive Premier P550 board
• Milk-V Megrez board

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Tumbleweed on Mars-CM (RISC-V board) by ph03nix

RISC-V is awesome, Tumbleweed is awesome, chocolate cake is awesome. I'm planning to combine all of them in one project.

Project Description

I recently purchased a MILK-V Mars CM and managed to setup it up already using Debian Linux. My project for this Hackweek is to see how far I can get to run Tumbleweed on this compute module board.

Goal for this Hackweek

• Run Tumbleweed on the Compute Module

Resources

• http://milkv.io/mars-cm
• https://en.opensuse.org/HCL:VisionFive2

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bpftrace contribution by mkoutny

Description

bpftrace is a great tool, no need to sing odes to it here. It can access any kernel data and process them in real time. It provides helpers for some common Linux kernel structures but not all.

Goals

• set up bpftrace toolchain
• learn about bpftrace implementation and internals
• implement support for percpu_counters
• look into some of the first issues
• send a refined PR (on Thu)

Resources

• https://bpftrace.org/
• https://docs.kernel.org/

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Backporting patches using LLM by jankara

Description

Backporting Linux kernel fixes (either for CVE issues or as part of general git-fixes workflow) is boring and mostly mechanical work (dealing with changes in context, renamed variables, new helper functions etc.). The idea of this project is to explore usage of LLM for backporting Linux kernel commits to SUSE kernels using LLM.

Goals

• Create safe environment allowing LLM to run and backport patches without exposing the whole filesystem to it (for privacy and security reasons).
• Write prompt that will guide LLM through the backporting process. Fine tune it based on experimental results.
• Explore success rate of LLMs when backporting various patches.

Resources

• Docker
• Gemini CLI

Repository

Current version of the container with some instructions for use are at: https://gitlab.suse.de/jankara/gemini-cli-backporter

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pudc - A PID 1 process that barks to the internet by mssola

Description

As a fun exercise in order to dig deeper into the Linux kernel, its interfaces, the RISC-V architecture, and all the dragons in between; I'm building a blog site cooked like this:

• The backend is written in a mixture of C and RISC-V assembly.
• The backend is actually PID1 (for real, not within a container).
• We poll and parse incoming HTTP requests ourselves.
• The frontend is a mere HTML page with htmx.

The project is meant to be Linux-specific, so I'm going to use io_uring, pidfs, namespaces, and Linux-specific features in order to drive all of this.

I'm open for suggestions and so on, but this is meant to be a solo project, as this is more of a learning exercise for me than anything else.

Goals

• Have a better understanding of different Linux features from user space down to the kernel internals.
• Most importantly: have fun.

Resources

• https://github.com/mssola/pudc

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dynticks-testing: analyse perf / trace-cmd output and aggregate data by m.crivellari

Description

dynticks-testing is a project started years ago by Frederic Weisbecker. One of the feature is to check the actual configuration (isolcpus, irqaffinity etc etc) and give feedback on it.

An important goal of this tool is to parse the output of trace-cmd / perf and provide more readable data, showing the duration of every events grouped by PID (showing also the CPU number, if the tasks has been migrated etc).

An example of data captured on my laptop (incomplete!!):

          -0     [005] dN.2. 20310.270699: sched_wakeup:         WaylandProxy:46380 [120] CPU:005
          -0     [005] d..2. 20310.270702: sched_switch:         swapper/5:0 [120] R ==> WaylandProxy:46380 [120]
...
    WaylandProxy-46380 [004] d..2. 20310.295397: sched_switch:         WaylandProxy:46380 [120] S ==> swapper/4:0 [120]
          -0     [006] d..2. 20310.295397: sched_switch:         swapper/6:0 [120] R ==> firefox:46373 [120]
         firefox-46373 [006] d..2. 20310.295408: sched_switch:         firefox:46373 [120] S ==> swapper/6:0 [120]
          -0     [004] dN.2. 20310.295466: sched_wakeup:         WaylandProxy:46380 [120] CPU:004

Output of noise_parse.py:

Task: WaylandProxy Pid: 46380 cpus: {4, 5} (Migrated!!!)
        Wakeup Latency                                Nr:        24     Duration:          89
        Sched switch: kworker/12:2                    Nr:         1     Duration:           6

My first contribution is around Nov. 2024!

Goals

• add more features (eg cpuset)
• test / bugfix

Resources

• Frederic's public repository: https://git.kernel.org/pub/scm/linux/kernel/git/frederic/dynticks-testing.git/
• https://docs.kernel.org/timers/no_hz.html#testing

Progresses

isolcpus and cpusets implemented and merged in master: dynticks-testing.git commit

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early stage kdump support by mbrugger

Project Description

When we experience a early boot crash, we are not able to analyze the kernel dump, as user-space wasn't able to load the crash system. The idea is to make the crash system compiled into the host kernel (think of initramfs) so that we can create a kernel dump really early in the boot process.

Goal for the Hackweeks

1. Investigate if this is possible and the implications it would have (done in HW21)
2. Hack up a PoC (done in HW22 and HW23)
3. Prepare RFC series (giving it's only one week, we are entering wishful thinking territory here).

update HW23

• I was able to include the crash kernel into the kernel Image.
• I'll need to find a way to load that from init/main.c:start_kernel() probably after kcsan_init()
• I workaround for a smoke test was to hack kexec_file_load() systemcall which has two problems:
  1. My initramfs in the porduction kernel does not have a new enough kexec version, that's not a blocker but where the week ended
  2. As the crash kernel is part of init.data it will be already stale once I can call kexec_file_load() from user-space.

The solution is probably to rewrite the POC so that the invocation can be done from init.text (that's my theory) but I'm not sure if I can reuse the kexec infrastructure in the kernel from there, which I rely on heavily.

update HW24

• Day1
  • rebased on v6.12 with no problems others then me breaking the config
  • setting up a new compilation and qemu/virtme env
  • getting desperate as nothing works that used to work
• Day 2
  • getting to call the invocation of loading the early kernel from __init after kcsan_init()

• Day 3

  • fix problem of memdup not being able to alloc so much memory... use 64K page sizes for now
  • code refactoring
  • I'm now able to load the crash kernel
  • When using virtme I can boot into the crash kernel, also it doesn't boot completely (major milestone!), crash in elfcorehdr_read_notes()

• Day 4

  • crash systems crashes (no pun intended) in copy_old_mempage() link; will need to understand elfcorehdr...
  • call path vmcore_init() -> parse_crash_elf_headers() -> elfcorehdr_read() -> read_from_oldmem() -> copy_oldmem_page() -> copy_to_iter()

• Day 5

  • hacking arch/arm64/kernel/crash_dump.c:copy_old_mempage() to see if crash system really starts. It does.
  • fun fact: retested with more reserved memory and with UEFI FW, host kernel crashes in init but directly starts the crash kernel, so it works (somehow) \o/

update HW25

• Day 1
  • rebased crash-kernel on v6.12.59 (for now), still crashing

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Smart lighting with Pico 2 by jmodak

Description

I am trying to create a smart-lighting project with a Raspberry Pi Pico that reacts to a movie's visuals and audio that involves combining two distinct functions: ambient screen lighting(visual response) and sound-reactive lighting(audio response)

Goals

• Visuals: Capturing the screen's colour requires an external device to analyse screen content and send colour data to the MCU via serial communication.
• Audio: A sound sensor module connected directly to the Pico that can detect sound volume.
• Pico 2W: The MCU receives data fro, both inputs and controls an LED strip.

Resources

• Raspberry Pi Pico 2 W
• RGB LED strip
• Sound detecting sensor
• Power supply
• breadboard and wires

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Port some classic game to Linux by MDoucha

Let's pick some old classic game, reverse engineer the data formats and game rules and write an open source engine for it from scratch. Some games from 1990s are simple enough that we could have a playable prototype by the end of the week.

Write which games you'd like to hack on in the comments. Don't forget to check e.g. on Open Source Game Clones, Github and SourceForge whether the game is ported already.

Hack Week 25 - Master of Orion II: Battle at Antares

Work on Master of Orion II continued with Tech Review and Colony list screens.

Hack Week 24 - Master of Orion II: Battle at Antares & Chaos Overlords

Work on Master of Orion II continues but we can hack more than one game. Chaos Overlords is a dystopian, lighthearted, cyberpunk turn-based strategy game originally released in 1996 for Windows 95 and Mac OS. The player takes on the role of a Chaos Overlord, attempting to control a city. Gameplay involves hiring mercenary gangs and deploying them on an 8-by-8 grid of city sectors to generate income, occupy sectors and take over the city.

How to ~~install & play~~ observe the decompilation progress:

• Clone the Git repository
• A playable reimplementation does not exist yet, but when it does, it will be linked in the repository mentioned above.

Further work needed:

• Analyze the remaining unknown data structures, most of which are related to the AI.
• Decompile the AI completely. The strong AI is part of the appeal of the game. It cannot be left out.
• Reimplement the game.

Hack Week 20, 21, 22 & 23 - Master of Orion II: Battle at Antares

Master of Orion II is one of the greatest turn-based 4X games of the 1990s. Explore the galaxy, colonize planets, research new technologies, fight space monsters and alien empires and in the end, become the ruler of the galaxy one way or another.

How to install & play:

• Clone the Git repository
• Run ./bootstrap; ./configure; make && make install
• Copy all *.LBX files from the original Master of Orion II to the installation data directory (/usr/local/share/openorion2 by default)
• Run openorion2

Further work needed:

• Analyze the rest of the original savegame format and a few remaining data files.
• Implement most of the game. The open source engine currently supports only loading saved games from the original version and viewing the galaxy map, fleet management and list of known planets.

Hack Week 19 - Signus: The Artifact Wars

Signus is a Czech turn-based strategy game similar to Panzer General or Battle Isle series. Originally published in 1998 and open-sourced by the original developers in 2003.

How to install & play:

• Clone the Git repository
• Run ./bootstrap; ./configure; make && make install in both signus and signus-data directories.
• Run signus

Further work needed:

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