# README

* [Linux Kernel](#linux-kernel)
  * [Subsystems selected](#subsystems-selected)
  * [Notes](#notes)
  * [Extras](#extras)
  * [Readings](#readings)

## Linux Kernel

For people who are very new to kernel and kernel development:

* I will **highly recommend** you to first complete [MIT 6.1810: Operating System Engineering](https://pdos.csail.mit.edu/6.828/2023/index.html) Labs and Readings together with a linux kernel book like [Understanding the Linux Kernel 3e: From I/O Ports to Process Management](https://www.amazon.in/Understanding-Linux-Kernel-Daniel-Bovet/dp/0596005652).
* This book goes into much details which is not needed, just sift through the chapters along with `xv6 book` in the MIT course.
* Look into theory and complete the labs.

Once you are done with the course, you will have good background to explore the linux kernel source.

### Subsystems selected

1. Devicetree
2. DRM (GPU)
3. eBPF (Tracing)
4. Bcachefs (Filesystem)

### Notes

* [Debugging](https://lagnos.gitbook.io/linux-kernel-notes/debugging-tracing/debugging)
  * [Step 1 : Getting and understanding the logs](https://lagnos.gitbook.io/linux-kernel-notes/debugging-tracing/debugging#step-1--getting-and-understanding-the-logs)
  * [Step 2 : Debugging with GDB and QEMU/libvirt](https://lagnos.gitbook.io/linux-kernel-notes/debugging-tracing/debugging#step-2--debugging-with-gdb-and-qemulibvirt)
  * [Extras](https://lagnos.gitbook.io/linux-kernel-notes/debugging-tracing/debugging#extras)
* [Finding Bugs](https://lagnos.gitbook.io/linux-kernel-notes/debugging-tracing/finding-bugs)
* [Event tracing](https://lagnos.gitbook.io/linux-kernel-notes/debugging-tracing/tracing)
  * [eBPF tracing](https://lagnos.gitbook.io/linux-kernel-notes/debugging-tracing/ebpf-tracing)(*TODO*)
* Kernel Concepts
  * [Interrupts](https://lagnos.gitbook.io/linux-kernel-notes/concepts/interrupts)
    * [Syscalls](https://lagnos.gitbook.io/linux-kernel-notes/concepts/syscalls/syscalls)
* [Kernel Core APIs](https://lagnos.gitbook.io/linux-kernel-notes/core-apis/core-apis) (*TODO*)
  * Core Utilities
    * [Notification Mechanisms](https://lagnos.gitbook.io/linux-kernel-notes/core-apis/core-utilities/notification-mechanism)
    * [Printk](https://lagnos.gitbook.io/linux-kernel-notes/core-apis/core-utilities/printk)
    * [Symbols and Assembler Notations](https://lagnos.gitbook.io/linux-kernel-notes/core-apis/core-utilities/symbols-assemblers)
    * [Workqueues](https://lagnos.gitbook.io/linux-kernel-notes/core-apis/core-utilities/workqueue)
  * [Kobjects](https://lagnos.gitbook.io/linux-kernel-notes/core-apis/kobjects)
* Kernel Subsystems
  * Devicetree
    * [Devicetree Yamls](https://lagnos.gitbook.io/linux-kernel-notes/subsystems/device-tree/devicetree-yaml)
    * [Testing yaml dtschemas](https://lagnos.gitbook.io/linux-kernel-notes/subsystems/device-tree/testing-schema)
  * Graphics (*TODO*)
* Implementations
  * [Pipes and Splices](https://lagnos.gitbook.io/linux-kernel-notes/implementations/pipes)
* [Kernel Mentorship Program](https://lagnos.gitbook.io/linux-kernel-notes/lkmp/mentorship) (*TODO*)
  * [Prerequisites](https://lagnos.gitbook.io/linux-kernel-notes/lkmp/prerequisites) (*TODO*)
  * Setting up the Kernel (*TODO*)

### Extras

* Kernel Boot Process (*TODO*)
* [Syzkaller Notes](https://lagnos.gitbook.io/linux-kernel-notes/debugging-tracing/syzkaller)
* [eBPF Tracing](https://lagnos.gitbook.io/linux-kernel-notes/debugging-tracing/ebpf-tracing) (*TODO*)
* [RCU in Kernel](https://lagnos.gitbook.io/linux-kernel-notes/extras/rcu) (*TODO*)

### Readings

1. Linux Kernel Development by Robert Love (3rd Edition) [Amazon Link](https://www.amazon.in/Linux-Kernel-Development-Developers-Library/dp/0672329468)
2. Linux Device Drivers 3ed by Johnathan Corbet, Alessandro Rubini, and Greg Kroah-Hartman [Amazon Link](https://www.amazon.in/dp/8173668493/?coliid=I17OESPBYIRQO5\&colid=2OMG77SFUJMQ3\&psc=1\&ref_=list_c_wl_lv_ov_lig_dp_it)
3. Understanding the Linux Kernel 3e: From I/O Ports to Process Management [Amazon Link](https://www.amazon.in/Understanding-Linux-Kernel-Daniel-Bovet/dp/0596005652)
4. Design of the UNIX Operating System by Maurice J. Bach (AT\&T Bell Labs) [Amazon Link](https://www.amazon.in/Design-UNIX-Operating-System-1/dp/9332549575/)

> Other readings are mentioned in the respective notes' README.md