macOS Darwin and XNU Kernel

1. Kernel architecture overview

   XNU composition of Mach, BSD and I/O Kit.

2. Mach overview

   Tasks, threads, ports and messages.

3. I/O Kit

   Driver families, nubs and IOKit matching.

4. Scheduling

   Mach scheduling and thread priorities.

5. Virtual memory

   Mach VM maps, objects and pagers.

6. Security considerations

   Kernel-level security concerns such as privileges, code signing and kext loading.

7. System extensions

   User-space replacements for kernel extensions.

8. DriverKit

   User-space drivers built on DriverKit with IOUserClient and dext packaging.

9. Grand Central Dispatch

   Dispatch queues, groups and sources.

Each section links to the official page. Titles and summaries by Extra Credit; the docs belong to their authors.

• Linux Memory Management
• Linux Namespaces
• Linux Networking Stack
• Linux Process Scheduling
• Linux Security Modules
• macOS App Sandbox
• macOS launchd
• macOS XPC
• POSIX Threads (pthreads)
• systemd
• Windows Driver Development
• Windows Services