DUJINLABS.COM

SYSTEMS FIELD NOTES
VOL. 01 — 2026

Linux Kernel · Embedded Systems · SoC Bring-up

Linux Kernel & Embedded Systems, From power-on to userspace.

DUJINLABS / FIELD NOTE 001

These notes follow real source locations and boot boundaries, from the register state handed off by the bootloader through kernel initialization, device drivers, and the root file system.

No ads. No banners, affiliate links, or sponsored posts. Just technical content.

Full sitemap Explore the learning path Read kernel notes

Site Map

Full sitemap

Browse by category, or search article titles and file paths.

Loading all public pages.

Dedicated sitemap (Korean)

View every link on one page (Korean)

Complete link list (Korean)

Bring-up Path

From power-on to userspace

Each boot stage is tied to real code, initialization boundaries, and the state passed to the next stage.

Section 01 / Linux

Linux

Kernel

Notes on kernel internals and board-dependent areas such as scheduling, memory, interrupts, device drivers, devicetree, and power management.

ARM64 · Linux v6.18.37 ARM64 kernel assembly · Concepts and code analysis Explore 18 files from Linux v6.18.37 by topic. Follow diagrams and GIFs, then switch to detailed analysis and source. The series is in Korean. (Korean) Linux Kernel Notes Linux 6.18.37 LTS arm64 head.S, line by line A visual walkthrough of the Image header, primary_entry, ID map, MMU enable, EL transitions, secondary CPUs, and KASLR relocation. (Korean)
Linux Kernel Browse subtopics

Architecture

ARM64 assembly: 18 files (Korean) ARMv9-A concepts and Linux source: 13-part guide (Korean) arm64 / x86-64 / RISC-V: 21-part comparison (Korean) arm64 head.S (Korean) x86-64 boot / paging (Korean) x86-64 IDT / SMP (Korean) RISC-V head.S / SATP (Korean) RISC-V trap / SBI (Korean)

Boot / Init

arm64 Image header (Korean) primary_entry (Korean) __primary_switch (Korean) start_kernel() (Korean) setup_arch() (Korean) rest_init() (Korean) kernel_init_freeable() (Korean) Launching the init process (Korean)

Memory

memblock (Korean) paging_init (Korean) mm_core_init (Korean) buddy allocator (Korean) SLUB (Korean) vmalloc (Korean) page fault (Korean) reclaim (Korean) compaction (Korean)

Scheduler

sched_init (Korean) CFS (Korean) RT scheduler (Korean) scheduler tick (Korean) load balancing (Korean) NOHZ (Korean)

IRQ / Time

early_irq_init (Korean) init_IRQ (Korean) GIC (Korean) softirq (Korean) hrtimer (Korean) timekeeping (Korean)

Process / Syscall

fork_init (Korean) copy_process (Korean) execve (Korean) exit (Korean) syscall entry (Korean) signal (Korean)

File System

vfs_caches_init (Korean) path lookup (Korean) open/read/write (Korean) page cache (Korean) ext4 (Korean) f2fs (Korean)

Block / Storage

bio (Korean) request queue (Korean) I/O scheduler (Korean) partition scan (Korean) eMMC/UFS (Korean)

Network

net_ns_init (Korean) netdev (Korean) RX path (Korean) TX path (Korean) socket (Korean)

Driver / Device

driver_init (Korean) device tree (Korean) platform driver (Korean) clock/reset/regulator (Korean) runtime PM (Korean)

Locking / RCU

spinlock (Korean) mutex (Korean) RCU init (Korean) lockdep (Korean) atomic/refcount (Korean)

Observe / Debug / Test

tracing / unwind (Korean) Trace documentation (Korean) eBPF documentation (Korean) KUnit documentation (Korean)

Security / Virtualization

KVM architecture (Korean) Security documentation (Korean) Virtualization documentation (Korean)

Platform / Driver API

DMA / IOMMU (Korean) power / suspend (Korean) module relocation (Korean) Core API documentation (Korean) Driver API documentation (Korean) Devicetree documentation (Korean)

System Programming

Executable examples that use the kernel ABI from userspace: processes, threads, signals, IPC, file descriptors, mmap, epoll, and sockets.

Linux System Programming From executable code to syscalls and kernel objects Thirty-eight topics organized around runnable C programs, annotated snippets, call-flow diagrams, failure conditions, and verification experiments.
System Programming Browse subtopics

Syscall / ELF

libc and syscalls How ./program executes errno / EINTR ELF / _start dynamic linker

Process

fork / COW execve waitpid / pidfd group / session service supervision

File Descriptor / I/O

fd / openat2 read / write loop dup / redirection link / rename directory walk fcntl / ioctl

Virtual Memory

address space mmap shared/private mprotect / madvise malloc / brk / mmap

Signal / Event / IPC

interrupt / event / signal signal delivery epoll timerfd / eventfd SCM_RIGHTS shared memory inotify

Thread / Synchronization

pthread lifecycle mutex / condvar atomic / futex

Socket

socket lifecycle nonblocking connect TCP framing UDP datagram getaddrinfo

Observe / Harden

io_uring seccomp / capability proc / strace / perf

Hardware

From the board to Linux

Step-by-step verification from power, reset, clocks, and physical signals through controller registers, firmware descriptions, Linux probing, and runtime paths.

Browse all hardware notes (Korean)

Documents

The complete set of 4,891 target documents has been translated into Korean and reviewed while preserving Linux 6.18.37 Documentation/ source paths and structure. Code, configuration names, ABI notation, and SPDX licenses remain unchanged.

Linux Documentation · Complete Linux 6.18.37 documentation corpus Browse the corpus by topic and inspect the original source path and final comparison status for every document.
Full translations
4,891 / 4,891
Forward comparison
3,324 RST
Reverse index
3,360 docs
Remote-only · unresolved
0 · 0
Documentation/networking/napi.rst NAPI Documentation/networking/sfp-phylink.rst phylink

RTOS

Zephyr RTOS

Technical notes on threads, scheduling, interrupts, the device model, devicetree, Kconfig, and west build flow, based on Zephyr 3.7.0 LTS3.

Browse Zephyr RTOS notes (Korean)

Zephyr 3.7.0 LTS3

Zephyr is an open-source RTOS that scales from small MCUs to SMP SoCs. These notes go beyond API summaries to trace where build-time generated objects meet runtime state transitions.

Zephyr RTOS Browse subtopics

Kernel

Kernel Architecture (Korean) Thread / Scheduler (Korean) Interrupt / Exception (Korean) Memory Management (Korean)

Device / Board

Device Model (Korean) Driver Model (Korean) Devicetree (Korean) Board Porting (Korean)

Build / Config

Kconfig (Korean) Build System / west (Korean)

Runtime Services

IPC / Synchronization (Korean) Timer / Workqueue (Korean) Networking (Korean)

Documents

Korean translation corpus Kernel Services (Korean)

Bootloader

Bootloader

Initialization after ROM, storage, trusted boot, the Secure World, and kernel handoff are examined separately through U-Boot, LK, Barebox, TF-A, and OP-TEE.

U-Boot

v2026.07 · ARM64, x86-64, RISC-V, SPL/TPL, relocation, driver model, storage, bootflow, FIT, fastboot, Linux handoff · 22 topics

(Korean) LK

20 topics separating the upstream LK core from classic AOSP aboot: threads, timers, apps, Android boot images, and fastboot

(Korean) Barebox

v2026.06.1 · PBL, initcall, device model, devfs, environment/state, bootchooser, bootm, BBU · 19 topics

(Korean) Trusted Firmware-A

LTS 2.14.3 · FIP, BL1/BL2/BL31, Chain of Trust, EL3 runtime service, PSCI, GIC, BL32/BL33 handoff · 12 topics

(Korean) OP-TEE

4.10.0 · S-EL1 entry, MMU/pager, secure thread, SMC message, TA session, secure storage, RPC · 12 topics

(Korean)

File System

File system

VFS, block layer, ext4, f2fs, initramfs, mount, overlay, partition layout, and device-node configuration.

Reading Notes

Book Review

Reading notes on computer architecture, operating systems, Linux, embedded systems, and electronics, connecting each book's main arguments to real implementations and practical scope.

No articles published yet.

Intelligent Systems

AI

From model architecture and training principles to inference runtimes, accelerators, edge deployment, and Linux-based AI systems.

No articles published yet.

Profile

A personal technical site for low-level systems development and bring-up field notes.

Linux kernel internals Zephyr RTOS internals System programming U-Boot · LK · Barebox File system