linux-kernel-architecture

name	linux-kernel-architecture
description	Linux kernel architecture skill for subsystem overview. Use when navigating kernel source, understanding boot flow, initcalls, or major subsystems (VFS, scheduler, MM). Activates on queries about kernel architecture, boot process, initcall levels, subsystem layout, or where code lives in linux.git.

Linux Kernel Architecture

Purpose

Provide a mental map of the Linux kernel: boot sequence, major subsystems, key data structures, and where to look in source — complementing skills/kernel/kernel-internals with architecture-level navigation for driver and subsystem work.

When to Use

• First time exploring linux.git for a feature or bug
• Understanding how boot reaches init and driver probe
• Tracing a syscall or interrupt through subsystems
• Onboarding before skills/kernel-dev/platform-device-model or driver skills

Workflow

1. Boot flow (x86/ARM64 simplified)

firmware/UEFI
├── arch/*/boot — decompress kernel, early setup
├── start_kernel() — mm, scheduler, timers, IRQ subsys
├── rest_init() → kernel_init → run_init_process
└── userspace init (systemd)

Driver module_init / device_initcall run during start_kernel before init.

2. Major subsystems

Subsystem	Path (typical)	Key structs
Scheduler	kernel/sched/	task_struct, sched_entity
Memory	mm/	, ,