System DesignSystem Design
Swap on Embedded Linux: zram, Flash Swap or No Swap?
Swap on embedded Linux: compare no swap, zram and swap on eMMC or SD flash, with a recommended setup, PSI monitoring and…
RB Oct 17 · 9 min
Corporate on-site training - Submit proposal Pick your modulesSharpen your kernel skills: deep dives, drivers, Yocto, CVEs, careers — updated daily. Read the blog →
~/ blog
Field notes from the Linux trenches
Deep dives, debugging war-stories and career guidance for engineers who work where the kernel meets real hardware.
System Design
Debug StoriesDebug Stories
Sleeping Function Warning: Invalid Context in a PREEMPT_RT Console Thread
On a PREEMPT_RT kernel with debug checks enabled, the console printing thread triggered a sleeping function warning. Here is how the report…
RB Oct 14 · 14 min
Deep DivesDeep Dives
What PREEMPT_RT Changes: Priority Inheritance (Part 2)
Priority inheritance in the Linux rtmutex assigns, never increments. The two waiter trees, the chain walk, max_lock_depth, and why semaphores get none.
RB Oct 10 · 17 min
Kernel SecurityKernel Security
Linux Kernel CVEs: What to Patch by Device (4 – 10 Oct 2026)
220 Linux kernel CVEs (4 - 10 Oct 2026) with the minimum safe version per branch - including CVE-2026-98323, CVE-2026-98365 and what…
RB Oct 10 · 14 min
System DesignSystem Design
Vendor BSP vs Mainline Kernel: What Each Choice Costs After Your First Release
Vendor BSP vs mainline kernel for an embedded Linux product: when each fits, what each costs in updates and security, and how…
RB Oct 7 · 8 min
NewsNews
Kernel & Embedded News: U-Boot 2026.10 Released; Meta Proposes CRAM
U-Boot 2026.10 ships with dm-verity support in FIT images; Meta proposes CRAM compressed RAM; Pixel 10 device trees head for mainline Linux…
RB Oct 6 · 9 min
InsightsInsights
LTP CVE Tests: How to Prove a Kernel Fix Reached Your Board
Your BSP reports a kernel version that should contain a given CVE fix. That is a claim about the tag it was…
RB Oct 5 · 14 min
CareerCareer
Why judgment compounds more slowly—and more durably—than tool knowledge
Tool knowledge pays back in the first week but resets with every new version. Judgment pays back more slowly, yet it builds…
RB Oct 4 · 8 min
TutorialsTutorials
Building Linux for a RISC-V Board — Part 2: Building OpenSBI Firmware and U-Boot from Source
Build the OpenSBI firmware and U-Boot for RISC-V from source, then boot a kernel through the full chain in QEMU. The addresses…
RB Oct 4 · 17 min
Deep DivesDeep Dives
From start_kernel() to Userspace: A Line-by-Line Walkthrough
Walk the path from start_kernel to userspace on arm64: rest_init, kernel_init, the initcall levels, and the fixed order the kernel searches for…
RB Oct 3 · 20 min
Kernel SecurityKernel Security
Linux Kernel CVEs: What to Patch by Device (27 Sep – 3 Oct 2026)
1 Linux kernel CVE (27 Sep - 3 Oct 2026) with the minimum safe version per branch - including CVE-2026-98164 in KVM…
RB Oct 3 · 6 min
System DesignSystem Design
Embedded Linux Device Heartbeat Design: How Often, What to Report, and What Failure Means
How to choose a device heartbeat interval, decide what each field must report, and tell a failed network path apart from a…
RB Oct 3 · 28 min
AutomotiveAutomotive
Android Automotive Kernel End-of-Life: How to Find the Date That Applies to Your Build
An Android Automotive kernel on GKI has two Google end dates, and kernel.org gives neither. How to identify the shipped release and…
RB Oct 2 · 20 min
Kernel SecurityKernel Security
Open-Source Device CVEs: What to Patch by Vertical (September 2026)
Open-source device CVEs for September 2026: what U-Boot, OpenSSL, BlueZ and the rest of your device stack expose this month, and what…
RB Oct 2 · 16 min
CareerCareer
AI-Assisted Learning or Avoidance: How to Check Which One You Are Doing
Using an AI assistant can build your skill or replace it, and the two look almost the same from outside. What research…
RB Oct 2 · 7 min
The fortnightly digest
One email every two weeks — the best of our kernel & embedded writing, plus a hand-picked link or two. No spam.
// 1,200+ embedded engineers already read it
We email occasionally and never share your address.