Play with esp32 to create domotics stuff by aginies

Description

Play with ESP32 board and multiple small peripherals

https://github.com/aginies/domotique

Goals

• Finish the pool project
• add support of NFC auth in the door project
• improve the doc
• project to manage solar panel (router)

Resources

esp32 home

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Add Qualcomm Snapdragon 765G (SM7250) basic device tree to mainline linux kernel by pvorel

Qualcomm Snapdragon 765G (SM7250) (smartphone SoC) has no support in the linux kernel, nor in u-boot. Try to add basic device tree support. The hardest part will be to create boot.img which will be accepted by phone.

UART is available for smartphone :).

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Improve UML page fault handler by ptesarik

Description

Improve UML handling of segmentation faults in kernel mode. Although such page faults are generally caused by a kernel bug, it is annoying if they cause an infinite loop, or panic the kernel. More importantly, a robust implementation allows to write KUnit tests for various guard pages, preventing potential kernel self-protection regressions.

Goals

Convert the UML page fault handler to use oops_* helpers, go through a few review rounds and finally get my patch series merged in 6.14.

Resources

Wrong initial attempt: https://lore.kernel.org/lkml/20231215121431.680-1-petrtesarik@huaweicloud.com/T/

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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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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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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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Capyboard, ESP32 Development Board for Education by emiler

Capyboard is an ESP32 development board built to accept individual custom-made modules. The board is created primarily for use in education, where you want to focus on embedded programming instead of spending time with connecting cables and parts on a breadboard, as you would with Arduino and other such devices. The board is not limited only to education and it can be used to build, for instance, a very powerful internal meteo-station and so on.

• github.com/realcharmer/capyboard
• github.com/realcharmer/capyboard-starter
• github.com/realcharmer/capyboard-docs
• github.com/realcharmer/capyboard-examples
• docs.capyboard.dev

Hack Week 25

My plan is to create a new revision of the board with updated dimensions and possibly even use a new ESP32 with Zigbee/Thread support. I also want to create an extensive library of example projects and expand the documentation. It would be nice to also design additional modules, such as multiplexer or an environment module.

Goals

• Implement changes to a new board revision
• Design additional modules
• Expand documentation and examples
• Migrate documentation backend from MkDocs to Zensical

Hack Week 24

I created a new motherboard revision after testing my previous prototype, as well as a light module. This project was also a part of my master's thesis, which was defended successfully.

Goals

• Finish testing of a new prototype
• Publish source files
• Documentation completion
• Finish writing thesis

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Backfire TV - Take back control of your Firestick by andreabenini

Take Back Control of Your Amazon Firestick.
Tired of Ads, a cluttered launcher, and buttons you can't change? BackFireTV is a project to liberate your Firestick from Amazon's walled garden and make it truly yours. They call it the firestick. To fight fire with fire, you need a backfire.

That's the soul of BackFireTV. To truly liberate it and return back to its core capabilities this project uses a linux script, one Android app and ADB access against Amazon's restrictive policies. We leverage these internal tools to create a "backfire" against the incessant ads and locked ecosystem, transforming your Firestick back into the useful, customizable device it was always meant to be.

The Problem

The Amazon Firestick starts as an excellent, affordable streaming device. However, Amazon's aggressive Ad policies and restrictive ecosystem have turned it into an increasingly annoying and a less useful device. It comes with frustrations:
- Messy interface. The less the better was probably the best slogan for the early device, its interface is now cluttered and chaotic when you probably need just a couple of buttons for starting your favorite applications.
- Constant Ads. The default launcher is filled with commercials and sponsored content.
- Bloated Interface. A cluttered and slow home screen you can't customize.
- Locked Buttons. Dedicated buttons for services you don't use (like popular streaming providers) that can't be easily changed.
- Lack of Control. A closed ecosystem that limits what you can do.

I could overlook them all if the device was provided for free. But since you pay and you own it it should be legit to do whatever you please in your personal device and network.

The Solution: BackFireTV

BackFireTV hacks your Firestick to give you back control. It uses a clever system of DHCP hooks and ADB (Android Debug Bridge) commands to remotely manage your device, block annoyances and customize your experience from the moment it connects to your network.
The dhcp lease action starts a nohup command on the firestick and forgets about it, the daemon then manages running programs, hacks remote control features and keys. It can be paused or resumed, no rooting required.

Features

• Custom Launcher. Automatically replaces the default Amazon launcher with the lean and clean Wolf Launcher.
• Ad-Free Experience:. Blocks annoying ads and sponsored content for a cleaner interface.
• Button Remapping. Reprogram the physical buttons on your remote. For example, make the Disney+ button launch Kodi or your favorite application.
• Works on every firestick 4K. Tested on: Firestick TV 4k (1st/2nd gen), Firestick TV 4k Max.
• No rooting required. It runs on basic user permissions with standard privileges. It also works on standard devices: latest firmware, with or without external hw attached (usb storage, network cards, usb hubs, ...).
• No banned apps. This hack relies on the linux subsystem underneath, no matter what Amazon does on the AppStore, this script can always be sideloaded and cannot be banned (no fingerprints on android app layer).
• Toggle to default anytime. Standard amazon launcher can still be toggled any time for administrative tasks or just as a comparison. Feel free to manage it as usual and switch back to

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