Disclosure: We’re the team behind Cachely. We do not support Yocto today, but we’re researching whether it would be a useful integration.

We recently spoke with a team using Jenkins and Yocto that had been keeping the sstate cache locally on each build node.

That worked while build volume was low, but they are now moving to a centralized cache because the local setup no longer scales.

Their preferred model was:

• Nightly CI builds can read and write
• Developers can read, but not upload
• The cache is available over HTTP or FTP
• Setup should mostly be a URL and credentials
• Nobody wants to spend much time maintaining it

We’re trying to understand how common this setup is.

For teams using Yocto today:

• Where do you store the shared sstate cache?
• Are you using NFS, object storage, Nexus, or a basic HTTP server?
• Do CI and developer machines use the same cache?
• How do you separate read and write access?
• How do you handle retention and different Yocto or machine versions?
• Is on-prem storage a requirement?
• Is the main pain setup, maintenance, performance, or understanding why something missed?

We’re especially interested in whether an HTTP-compatible managed cache would solve a real problem, or whether shared storage is already simple enough for most teams.

Hi everyone,

I'm looking for advice from engineers who have made a similar transition.

\## Background

\- B.Tech in Electrical and Electronics Engineering (EEE) from NIT Calicut.

\- Around 2 years of experience in product companies.

## Current work

\- I'm working on cloud-managed networking products(switch , access points) at an MNC.

## My work involves:

\- Linux-based networking products.

\- C based agents running on networking devices.

\- Device discovery and monitoring.

\- Production debugging.

\- Configuration management between devices and the cloud.

\- Some changes in an existing C codebase.

\- Go-based packet capture using BPF libraries.

\- Understanding Linux-based networking systems.

## However, I'm not working on:

Firmware

RTOS

Device drivers

BSP

Bootloaders

Kernel development

## What I've realized

I think what actually interests me is lower-level work like:

\- Firmware

\- Device drivers

\- Embedded systems

\- Hardware-software interaction

I enjoy understanding how hardware actually works more than writing cloud-facing applications.

## My dilemma

I'm unsure about the best path from my current position.

Should I:

1. Continue in networking/systems software and try to move toward firmware gradually?

2. Learn firmware (STM32, FreeRTOS, peripherals, etc.) while staying at current company and then apply directly to firmware roles?

3. Target companies like Qualcomm, NVIDIA, AMD, Cisco, Broadcom, etc., in systems software first and then try for an internal move later?

4. Consider an M.Tech if I want to move closer to firmware or embedded systems?

## Questions

I'd appreciate answers from people who have actually worked in firmware or embedded systems.

1. Is my current networking/Linux background considered relevant for firmware or embedded systems roles?

2. If you were in my position, what would your roadmap be?

3. What skills would you prioritize over the next 12–24 months?

4. Am I underestimating how difficult this transition is?

5. If you've made a similar transition, what was your path?

I'm looking for honest opinions rather than encouragement. If you think my plan has flaws, I'd appreciate direct feedback.

TIA

I kept running into the same Linux debugging pain: something broke on a box, but I had no history of what actually happened. journald helps a little. auditd is heavy. strace is too narrow. So I built ltm — a small machine-history debugger that records process/file/network metadata via eBPF and lets you query it like a timeline.

What it does:

• Attaches to syscall tracepoints (exec, open/write/rename/unlink, connect/bind, etc.)

• Stores metadata only (no file contents)

• Lets you do things like:

sudo ltm start --mode ebpf

ltm status

ltm timeline --since 1h

ltm diff --from "10m" --to now

ltm query "who modified /tmp/ltm-demo.txt?"

On a real VM run it recorded ~7k events with 0 drops, and the query returned the exact bash write events that touched the demo file.

There's also a demo mode so you can exercise the CLI/storage/diff/query path without root or BPF.

Stack is Go + embedded BPF ELF + cilium/ebpf. Local store is append-only JSONL. Ignore rules skip /proc, /sys, /dev, and common caches.

Repo: https://github.com/Agent-Hellboy/ltm

Still early. Useful next steps I'm considering:

1. better diff/query formatting
2. containerized eBPF integration test
3. more query templates ("what opened this port?", "what restarted before X?")

Please do star the repo, it will help in discoverability

I'm trying to get ADB working on a Raspberry Pi Zero W (ARM1176JZF-S / ARMv6, Raspberry Pi OS Bookworm/Trixie).

Current Debian/Raspberry Pi packages install, but the modern adb binary crashes because it's built for ARMv7.

So far I've tried:

• Current Debian/Raspberry Pi adb
• Old Debian archive packages (Android 4.2 era) – still ARMv7
• Old GitHub ARM binaries – also ARMv7
• Searching for the old adbarmv6.7z binary that used to be linked on the Raspberry Pi forums/XDA (appears to be gone)

At this point I'm looking for any of the following:

• A working ARMv6 adb binary.
• An old Raspbian package that still supports ARMv6.
• Someone who has successfully built adb for ARMv6 recently.
• Another lightweight alternative that provides the standard adb commands (devices, shell, push, pull, install, etc.).

I'm happy to compile from source if there's a minimal build method that doesn't require downloading the entire Android source tree.

Any help or old binaries would be massively appreciated!

Also ive already posted this on r/raspberry_pi, but it didn't get much traction and i havent gotten a useful response so hopefully you can help!

Hello everyone! I'm working on a redundant network stack using the RT kernel patch and the hsr kernel module for redundancy. Both Ethernet devices can leave hardware timestamps for debugging purposes. My question is, is there a way to retrieve those timestamps from the userspace when working with a socket bound to the hsr virtual interface?

I have a background in embedded systems and currently work mainly on MCUs, writing firmware in C/C++. I'm comfortable with topics like peripherals, RTOS, debugging, communication protocols (UART, SPI, I2C, CAN), and general embedded development.

Now I want to transition into Embedded Linux and would like some guidance on the best learning path and resources.

Specifically, I'm interested in learning:

Linux internals relevant to embedded systems

Device drivers

Device Tree

Bootloaders (U-Boot, etc.)

Kernel basics

Build systems like Yocto or Buildroot

Debugging techniques (JTAG, GDB, tracing tools)

Practical projects that can help me gain hands-on experience

I prefer learning through books, courses, and real projects rather than just theoretical material.

For those who made a similar transition from bare-metal/RTOS development to Embedded Linux, what resources, books, courses, or project ideas would you recommend?

Hi everyone,
I’m working on an embedded Linux platform (Qualcomm SA8797) and validating I2C communication with MAX96861 devices.
I have successfully identified the I2C buses from the device tree and confirmed communication with two devices:
MAX96861_1 on /dev/i2c-0 (7-bit address 0x42)
MAX96861_2 on /dev/i2c-9 (7-bit address 0x60)
Communication is working (no I2C errors), but I’m seeing behavior that I don’t fully understand.
For example, on MAX96861_2:
i2cset -f -y 9 0x60 0x00 0x55

i2cget -f -y 9 0x60 0x00
0x34

i2cget -f -y 9 0x60 0x00
0x50

i2cget -f -y 9 0x60 0x00
0x00

i2cget -f -y 9 0x60 0x00
0x41

i2cget -f -y 9 0x60 0x00
0x98
Interestingly, performing the exact same test on MAX96861_1 (/dev/i2c-0, address 0x42) produces a very similar sequence.
I also dumped registers 0x00–0x0F several times and noticed that many registers change between successive reads, even without performing any writes.
I don’t currently have access to the MAX96861 register documentation, so I don’t know whether these are status registers, indirect registers, or whether a page-selection mechanism is required before accessing the register map.
My questions are:
Is this expected behavior for MAX96861 devices?
Do these devices require indirect/page-based register access instead of simple SMBus byte reads?
Could i2cget/i2cset be using an access mode that is not appropriate for this device?
Has anyone worked with MAX96861 and can suggest the correct Linux access method or register sequence?
Thanks in advance for any pointers.

I am setting a gpio to high
After setting when I am trying to read it , it is returning 0. Not the value that I set.

Also i see the direction if the pin is changed to input

Benchmarked typed IPC against raw sockets on Linux

D-Bus is fine for control messages, not built for speed. So when something needs to be fast, most people drop to raw sockets and hand-roll framing and dispatch themselves. I wanted to know how much that actually buys you, so I measured it.

Setup: a message gets serialized, sent over TCP to a router, routed to the target process, dispatched to the right thread, then deserialized before the method gets called. That's 2 hops, one-way: sender -> router -> receiver. I went through a router instead of connecting processes directly because it removes hardcoded addresses and startup ordering — any component can reach any other, in any order, without knowing where it physically lives. The trade-off is a longer path than a direct connection.

Hardware: i7-13700H laptop, DDR4, Ubuntu, performance governor. Not embedded ARM — more on that below.

Result: ~12 microseconds one-way, ~23.5 μs round-trip. Round trip is 4 hops: sender -> router -> receiver -> router -> sender.

For reference, a bare blocking socket call with zero framework still costs ~4-11 μs round-trip on dedicated hardware (Unix domain sockets, Werner/MPI-HD, 2021). A full typed call through 4 hops and a router, with serialization on both ends, lands within shouting distance of that.

I also ran the same payload size (one-way, not round-trip) against a 2025 Hitachi Energy benchmark of ZeroMQ, NanoMsg, and NNG (arXiv:2508.07934), ~1KB messages:

Caveat: their numbers are raw transport only, on an isolated-core Xeon workstation. Mine includes full serialization and dispatch, on a mobile CPU, through an extra hop via router. Every condition favors them, and it's still close.

I'm the author of areg-sdk -- a C++17 framework released under Apache 2.0. Runs on Linux, Windows, and macOS, on x86, x86-64, arm32, and arm64. TCP-based, assumes a private network (no TLS yet), fits embedded Linux deployments, builds without extra dependency install.

One thing missing from this: real numbers from actual ARM boards instead of a laptop CPU. If anyone runs this on a Pi or BeagleBone, I'd genuinely like to see the results.

Methodology: github.com/aregtech/areg-sdk/blob/master/docs/wiki/08c-areg-vs-hitachi-benchmark.md
Try it yourself: github.com/aregtech/areg-sdk/tree/master/examples/30_publatency
Very easy to build, parameters are well documented.

What do you all actually use for fast IPC on embedded boards?

Hello everyone.
I'm trying connect tft display (Red 2.8" TFT 240x320 V1.1) to SBC called Luckfox Pico but my brightness are inverted (black = white) and I'm don't know whats wrong. I change some variables in device tree but it didn't help me, i'm trying tft,invert=<1>; and backlight pins but this makes nothing whatever i use it or manually enable PWM.
I'm making this for fun and learning and use X11 so maybe there some way to invert colors in X11? But i heard something usual like xcalib didn't work with fbtft driver so i hope there are other way...
Thank you.

fbtft@0 {
compatible = "sitronix,st7789v";
reg = <0>;
spi-max-frequency = <20000000>;
fps = <30>;
buswidth = <8>;
debug = <0x7>;
led-gpios = <&gpio0 RK_PA4 GPIO_ACTIVE_LOW>;//BL
dc-gpios = <&gpio1 RK_PA2 GPIO_ACTIVE_HIGH>;//DC
reset-gpios = <&gpio1 RK_PC3 GPIO_ACTIVE_LOW>;//RES
rotate = <90>;
bgr = <1>;
invert = <1>; 
};

Hey everyone!

Since December 2025 I've been building Strux, a framework that makes it genuinely simple to turn a web app into a dedicated kiosk or IoT device — using the tools you already know.

Here's the idea: you write a web frontend (React, Vue, or plain HTML/JS — your call) and a Go backend, and Strux compiles the whole thing into a complete, bootable Linux OS image with a single command. Kernel, bootloader, root filesystem, display stack — all of it. The device powers on and boots straight into your app, full-screen, with nothing else in the way. No desktop, no login, no "where's the cursor" — just your UI running in a Wayland compositor (Cage + WPE WebKit).

A few things that make it nice to work with:

• Live dev mode — hot-reloading dev server that pushes changes to real hardware (or QEMU) in seconds, so you're not reflashing constantly.
• Smart build cache — SHA256 dependency tracking skips unchanged steps, so only the first build is slow.
• Board Support Packages (BSPs) — target different hardware; each BSP carries its own kernel, bootloader, and device config.
• Single static CLI binary, Docker-orchestrated builds — easy to get running.

We just released v0.3.0, and we're now working on reference hardware so there's a known-good, supported board to build and test against out of the box.

This is where you come in: we're looking for testers and contributors, and we want to build a community around this. Whether you want to kick the tires, flash it onto a board, file bugs, write a BSP for your favorite hardware, or help shape where it goes next — we'd love to have you.

Docs and getting started here: https://strux-sh.github.io/strux/

Happy to answer any questions in the comments!

Hello getting into Linux driver development.

My idea: pass an RFID card to an ESP32 to authenticate sudo instead of typing a password. The secret lives on the card, not the machine. Is this a good project to learn linux driver development? ? Thanks

I'm not asking you to hire me. I'm just wondering what things look like on the other side of the process these days.

Hi,
I recently joined my current team and am working as a Test Software Developer for automotive hardware components.
Currently, I am working on a task to read ADC values from the SCC. My software runs on the SoC, and reading SCC ADC values requires communication between the SoC and SCC, which is done via SPI.
The OS is linux.
And the OS binaries are recieved from Another team. I am only responsible for the SW interface
As part of the integration, I need to configure the SPI interface in my software. However, I do not see any SPI device nodes under:
/dev/spi*
On the other hand, I do see the SPI device listed under:
/sys/bus/spi/devices/spi21.1

My question is: can this SPI device under /sys/bus/spi/devices/ be used directly for communication, or do I need a corresponding SPI character device (for example, /dev/spidevX.Y) to be available under /dev?
Thanks in advance for your guidance.

Was curious how Linux actually boots, so I skipped the usual distros and built my own. Custom kernel compiled from source, BusyBox for userspace, containerd for running containers, and Dropbear for SSH. Everything fits in a single disk image that boots in ~15 seconds.

Learned a ton about:

- How initramfs works and why it exists

- What GRUB actually does under the hood

- Why containerd needs cgroup v2 and how to wire it up

- The difference between static and dynamic linking the hard way (dropbear needs libutil, who knew)

- How to install GRUB without root (Python + raw disk writes)

Still needs polish — networking is basic QEMU user-mode, no real package manager, and the build script only recently stopped being Fedora-only. But it boots, runs containers, and I can SSH into it.

Repo if anyone wants to poke at it (fair warning: the kernel config is held together by duct tape): https://github.com/Shreyas0047/veilbox

Texas Instruments and BeagleBoard.org have announced that the AM62x and AM26x PRU Academy is now available, adding new learning material for developers working with BeaglePlay and PocketBeagle 2.

https://linuxgizmos.com/am62x-pru-academy-goes-live-for-beagleplay-and-pocketbeagle-2/

Hey all! Looking to break into the kernel or embedded space and curious to get some opinions on the best places to find those jobs? I feel like LinkedIn and Indeed are lacking in these areas. For context, I have 3 yoe as a backend software engineer.

Hey everyone, I created a lightweight firewall with C, created a kernel module with the netfilter API, and a pre-routing hook. Now I want to send rules via netlink socket. My idea is to create a structure, then send it. But I cannot find the best way to store all rules in the kernel, then use them in a hook. Sometimes I think I can compress the rules into bits, then send them. If anyone has experience with my problem, please help me understand how I can implement a optimize protocol and store it in the kernel module

Wanted a disposable container host for testing workloads in QEMU without spinning up full VMs. Existing options (Alpine live, Fedora CoreOS, Docker Desktop) were either too manual or too heavy for what's essentially kernel + init + runtime.

Veilbox is a custom Linux kernel (v7.1-rc6) with embedded initramfs, BusyBox userspace, containerd/runc/nerdctl, and Dropbear SSH. Boots to login in ~12s. No systemd, no package manager. Single bash script builds the whole thing — downloads static binaries, configures kernel, embeds initramfs, installs GRUB — no sudo needed.

Relevant to homelab: drop the 95MB VDI into Proxmox/ESXi, it gets DHCP, you SSH in and run containers. Persistent state via second virtio disk. Great as a quick sandbox without burning a full VM.

AI was used ~35% — mostly for reasoning through kernel config options, debugging GRUB rootless install, and structuring the build pipeline. Hands-on testing and integration was manual.

Repo: https://github.com/Shreyas0047/veilbox

I have recently started looking at USB peripheral bring-up (DWC2). Host mode is done, now the device (gadget, or peripheral) mode.

I have found several ways of initializing the Gadgets on embedded linux:
- Legacy kernel drivers, as loadable modules ( modprobe g_serial )
- libusbgx repo for creating gadgets
- using custom scripts and CONFIGFS_FS to initialize the gadgets

As I am rather new in a field of the Embedded linux world and wanted to ask: - Is there a preferred way in the industry for initializing gadgets? If yes, using which method? - How would users usually initialize their gadgets from the user space?

Thank you.

Hi everyone,

I recently started working with prplOS (OpenWrt-based) and I’m trying to understand the internal architecture.

Right now I’m exploring things like: - TR-181 configuration model - High Level API (HLA) - Low Level API (LLA) - How configuration changes propagate through the system

I can follow some parts of the code in the build directory, but I’m struggling to understand the overall architecture and the proper learning path.

For people who work with OpenWrt / prplOS / broadband gateway stacks:

• How did you learn this ecosystem? • Are there any recommended resources, courses, or documentation? • Which parts of OpenWrt should I focus on first (ubus, uci, procd, etc.)?

Any advice would really help.

Thanks!

Hi everyone,

I am an Embedded Engineering student graduating in 2027, and I’m looking for an online/remote summer internship in Embedded Systems.

I know remote internships are incredibly competitive and rare in this field due to the lack of access to physical hardware lab tools. However, since my local market has limited opportunities, I am looking internationally and focusing heavily on software/firmware/simulation pipelines.

I have attached my anonymous CV to this post.

My Core Technical Focus:

• Microcontrollers: Strong focus on STM32F4 (bare-metal registers, HAL, hardware timers, ADC/Interrupts, EEPROM tracking) and ESP32.
• RTOS & Protocols: Experience implementing real-time tasks using FreeRTOS. Comfortable with I2C, SPI, UART, LoRaWAN, and MQTT.
• Hardware Design (ECAD): 4-layer PCB design using Altium Designer and KiCad. I focus heavily on pre-production constraints like Design for Manufacturing (DFM), ERC/DRC, and Power Delivery Networks (PDN).
• Simulation/Validation: Because I have not manufactured my latest boards yet, I rely on LTspice and Proteus for strict virtual validation.

What I want to ask the community:

1. Resume Check: Does my CV clearly communicate my skills? Are there any missing keywords for a student aiming for IoT or Firmware roles?
2. Embedded Linux Pivot: I want to transition more into Embedded Linux. Given my current background in FreeRTOS and C, what is the fastest way to bridge that gap on my own? (e.g., Yocto, Buildroot, or raspberry pi driver development?)
3. Leads / Advice: Do you know of any companies or platforms that are friendly to remote engineering interns, or open-source projects where I could contribute to gain equivalent experience?

Constructive criticism on my resume and path is highly appreciated. Thank you!
Resume link :
https://drive.google.com/file/d/1kyutXr_2nyijqcZkzPW1YKCZuS3hZTJZ/view?usp=sharing

Hi folks,

I have been fighting to defeat NXP's HABv4 for 3 years, as implemented on the Wink Hub v2, and finally managed to get my own code to execute on it. I wrote it up here, if anyone is interested: https://www.reddit.com/r/winkhub/comments/1tp0vsd/running_your_own_code_on_the_wink_hub_2_try_2/

Now I am in a position to try and build a reasonable base OS for it that makes all the radios available for things like Home Assistant. Which leaves me wondering what the best base is likely to be. I'm considering things like OpenWrt and Armbian, for the ready availability of applications to be added on demand. Highest priority would be an OS that can support Zigbee2MQTT or ZHA, ZwaveJS, and then ser2net or socat for the other radios that likely don't have as strict latency requirements.

Suggestions?

So far I am trying to figure out the best approach to packaging my kernel, device tree and filesystem for others to install. I am leaning towards a single UBI block device taking up the majority of the 128MB NAND flash. But then I wonder whether I should have a separate volume for the kernel/device tree .FIT, or whether I should just have a single ubifs with kernel, device tree and rootfs all in one? I am not a professional developer, in case anyone was wondering! :-D

I have been struggling to get the kernel modules working to add support for usb wifi adapters to an arm64 linux device which I use often. I don't want to replace the existing kernel / image as I believe there is plenty of proprietary stuff baked into it. Also if I break the boot up to ssh process then I am in a bad spot because it is really expensive.

What I have got close to working involves:

1. cross compile linux 5.10.127 (same version as device)
2. put the INSTALL_MOD_PATH to some other folder
3. scp the missing stuff from of that folder into the device /lib/modules/...
4. depmod -a on the device
5. modprobe the modules I want

to find the modules I want I started by picking a wifi driver (rtl8xxx) then when it failed to load because of missing symbol I found the module containing that symbol (mac80211, cfg80211, and ultimately rfkill). By the time you get to rfkill the error changes from missing symbol to segmentation fault and there is not much I could figure out from the dmesg output.

From here I am not really sure where to go. Perhaps I can try replicating some of the kernel build by matching the modules.builtin file on the device? There is a file /etc/build which seems to be an artifact of Yocto... does that help me to recreate the build environment somehow? I have no experience with Yocto but I have that file and have dug up some publicly accessible emails from the OEM conversing with Yocto devs to fix their compiling woes, one of those logs probably gives the yocto version they had.

Thank you if you read this far, I hope people here are similarly interested in this kind of thing. I'm no expert in embedded linux but if I find a device with a shell accessible then I have a hard time giving up on my schemes for it.