Deep DivesDeep 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
Linux kernel & Device drivers starts on 24th Oct 2026 enrollingCorporate on-site training - Submit proposal Pick your modulesSharpen your kernel skills: deep dives, drivers, Yocto, CVEs, careers — updated daily. Read the blog →Embedded Linux fast track starts 30th sept 2026 enrollingEmbedded Linux Mastery track starts 30th sept 2026 enrollingLinux systems engineering starts 30th sept 2026 enrolling
~/ blog
Deep Dives
Articles in this topic.
Deep Dives
Deep DivesDeep 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 DivesDeep 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 DivesDeep 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 DivesDeep 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 DivesDeep 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 DivesDeep Dives
Inside the Linux DMA Core: From dma_map_phys() to the Cache Ops
Trace a DMA mapping through the Linux 7.x source: the dma-direct fast path, arm64 cache hooks, swiotlb bouncing, and CONFIG_DMA_API_DEBUG.
RB Jun 27 · 21 min
Deep DivesDeep 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 DivesDeep 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
Deep DivesDeep Dives
The Many Paths to init, Part 5: Unifying Themes
In this final installment of our series, we synthesize our exploration of diverse Linux boot processes by examining two critical, cross-platform themes:…
RB Sep 15 · 5 min
Deep DivesDeep Dives
The Many Paths to init, Part 4: The Specialists
Beyond PCs and general-purpose embedded systems lie platforms where the Linux boot process has been specialized to an extreme degree. In this…
RB Sep 13 · 4 min
Deep DivesDeep Dives
The Many Paths to init, Part 3: The Embedded Frontier
While the PC and server world has evolved towards the simplicity of Unified Kernel Images, the embedded systems domain—dominated by ARM and…
RB Sep 12 · 4 min
Deep DivesDeep Dives
The Many Paths to init, Part 2: The PC and Server Revolution
In the first part of our series, we established a four-stage framework for understanding any boot process. Now, we apply that model…
RB Sep 12 · 4 min
Deep DivesDeep Dives
The Many Paths to init, Part 1: The Universal Blueprint
At its core, booting is a procedure that takes a system from inert hardware to a fully operational state. This happens across…
RB Sep 11 · 4 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.