~/ blog — kernel · drivers · embedded · careers

Deep Dives

Articles in this topic.

filter: All Career News Deep Dives Insights Tutorials Edge AI Security Debug Stories System Design

Deep Dives

Embedded Linux Boot Time: The Phase You Are Not Measuring

Boot time spans four phases with four independent clocks, and dmesg only shows the third. How to put them all on one…

RB Aug 7 · 18 min

Deep Dives

dm-verity: How a Read-Only Rootfs Stays Verified

dm-verity gives an embedded device a tamper-evident read-only rootfs. Learn how per-block hash-tree checking works and why the root hash must be…

RB Aug 3 · 11 min

Deep Dives

Devres: How Managed Device Resources Work in the Linux Kernel

How managed device resources (devres) work in the Linux kernel: the devres list, devm_* APIs, release order on unbind, pitfalls, and CONFIG_DEBUG_DEVRES.

RB Aug 1 · 10 min

Deep Dives

System Device Trees and Yocto for Heterogeneous SoCs

A system device tree plus Yocto multiconfig builds Linux, bare-metal, and firmware for heterogeneous SoCs like ZynqMP from one hardware description.

RB Jul 27 · 9 min

Deep Dives

The Linux Generic IRQ Subsystem: From Device Tree to Handler

A walkthrough of the Linux generic IRQ subsystem: why it exists, irq_domain hwirq-to-virq mapping, flow handlers, irq_chip, and Device Tree to handler.

RB Jul 26 · 18 min

Deep Dives

The pinctrl Subsystem: How Linux Multiplexes and Configures SoC Pins

The pinctrl subsystem lets Linux multiplex and configure SoC pins from device tree. How pinmux and pinconf work, the consumer API, and…

RB Jul 25 · 8 min

Deep Dives

Runtime PM: Why Your Device Never Suspends, and How to Find Out

One kernel function, rpm_check_suspend_allowed(), decides whether runtime PM suspends your device. Each return code names the exact field to inspect.

RB Jul 18 · 10 min

Deep Dives

Picking a Vendor BSP Branch: The Highest Number Is Not the Maintained One

Qualcomm's qcom-6.19 has not moved since March while qcom-6.18.y is fed daily. How to tell a maintained vendor BSP branch from a…

RB Jul 14 · 7 min

Deep Dives

The Linux Common Clock Framework: How Clocks Are Modeled and Debugged

A deep dive into the Linux Common Clock Framework: struct clk_ops, the prepare/enable split, devm_clk_get_enabled, and debugging clocks disabled at boot via…

RB Jul 11 · 11 min

Deep Dives

Linux Workqueues: A Deep Dive into the Kernel’s Deferred Work Engine

A deep dive into Linux workqueues: how the kernel queues, wakes, and runs deferred work — from queue_work() to your handler, traced…

RB Jul 4 · 11 min

Deep Dives

Real-Time Linux vs RTOS: Zephyr, FreeRTOS, PREEMPT_RT

Real-time Linux vs RTOS, compared: FreeRTOS, Zephyr, and mainline PREEMPT_RT, and how mixed-criticality designs run Linux and an RTOS on one SoC.

RB Jul 1 · 15 min

Deep Dives

Coherent vs Streaming DMA: A Deep Dive into the Linux DMA Mapping API

A practical Deep Dive into the Linux DMA mapping API: coherent vs streaming mappings, DMA directions, cache coherency, and the rules that…

RB Jun 27 · 21 min

Deep Dives

Deferred Probe in the Linux Kernel: Why a Driver’s probe() Runs Late and How to Debug It

Deferred probe lets Linux drivers bind in any order by retrying devices whose dependencies are not ready. How the mechanism works in…

RB Jun 22 · 16 min

Deep Dives

Meet the sched_ext Ecosystem

This article provides a deep dive into the major scheduler classes, their unique design goals, and the management utilities powering the system.

RB Sep 17 · 4 min

Deep Dives

The sched_ext Architecture

sched_ext is not a scheduler; it's a framework that securely connects custom BPF programs to the core kernel. Its architecture consists of…

RB Sep 16 · 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.