Curated source guide

FreeBSD source explorer

Explore the FreeBSD kernel source code from the FreeBSD 15.1 release branch. Study sys/, boot, VM, VFS, networking, device drivers, and kernel configuration.

Guide chapters

1. Chapter 1 — The Kernel Tree
2. Chapter 2 — Boot And Kernel Entry
3. Chapter 3 — Processes, Threads, And Scheduling
4. Chapter 4 — Memory And Filesystems
5. Chapter 5 — Networking And Drivers

Key directories

• sys/ — Kernel source roadmap and directory overview
• sys/conf/ — Kernel build manifest that maps source files into configurations
• sys/amd64/conf/ — Representative amd64 kernel configuration
• stand/man/ — Loader manual covering the pre-kernel boot environment
• sys/amd64/amd64/ — Early amd64 assembly entry path
• sys/kern/ — Kernel initialization and the first process path