Adding Simple System Call in Linux Kernel

In this video I will add a hello world system call to the Linux kernel code and also show how it can be used from user mode.
Kernel Docs: www.kernel.org/doc/html/lates...
Online Kernel Code Viewer: elixir.bootlin.com/linux/late...

[@madisonhanberry6019]

Do the programming overlords know that you're giving us all this forbidden knowledge?

[@moritzrank01]

These videos are top notch, really enjoying the short digestable deep dives

[@andreasproteus1465]

Excellent.
Short and to the point.
And no narcissistic talking head.

[@r3v0lv3rz]

Consistent. Clear. Straight to the point. Love your work.

[@shubhamrasal8930]

Really cool. I always wondered how syscalls work.

[@boddz_]

Your content is brilliant mate. Keep it up throughout the new year.

[@teldrah]

Theae videos are insanely good, keep it up. I learned so much already.

[@liquidmobius]

happy new years, nir! thanks for the upload

[@john.darksoul]

Neat!
I like how you have to edit three different files to add a single system call :D

[@DavidEngelen]

Thanks for also explaining all the commands

[@ThousandsOfPk]

Awesome video - would love a productionized version once your happy with it

[@JeersNX]

This is perfectm thanks for being straight-forward.

[@pavfrang]

Wow, thanks that is phenomenal!

[@frzen]

I really enjoy these videos thanks

[@waldmensch2010]

for me as noob in programing, nice to see how it works

[@oPatrickVico]

Awesome! Thanks for the video

[@MillaGamer]

Nice, happy new yaer from Brazil!

[@DeVibe.]

Awesome!

[@mfaathirarsa]

yo mate i like your setup
what wm are you using? and do you have any config or dotfiles?

[@nirlichtman]

Thanks! I am using a port of Suckless dwm for Windows
The setup information is in the welcome link in the channel description (including my vimrc config file)

[@mfaathirarsa]

@@nirlichtman thx mate, i love your videos
i've started pursuing os development and your video really helps because they are concise and easy to understand, do you have any recommended resources?

[@nirlichtman]

@@mfaathirarsa Thanks! What kind of os dev? You mean programming user mode on Linux/Windows, kernel level programming or bare metal?

[@mfaathirarsa]

@@nirlichtman bare metal would be best because I'm trying to learn osdev from scratch, for now my resource is the osdev wiki

[@nirlichtman]

@@mfaathirarsa osdev is good from what i remember, also i would recommend checking out serenity os which is a work in progress os written in c++, the creator of this project also has a youtube channel in which he documents development of certain parts. Also i recommend learning how Linux/Windows boots up, it is very interesting and you can find a bunch of youtube videos about this, and also additional information on the linux kernel docs

[@JeersNX]

Now i'm remembering "548" forever

[@Abhishek-pp8ck]

Thanks!, can we call syscall through a single C program(file)?

[@nirlichtman]

Yes, you can call custom system calls (which don't have wrappers) from C using the syscall function, checkout "man 2 syscall" for more info

[@TaschenRechner22]

@@nirlichtman I think glibc provides C wrappers for many of the syscalls, right? Could you make a video showing how to add a syscall wrapper in glibc for your syscall? Glibc has some gnarly source code, so it would be cool to see how one grapples with that to add new syscall wrappers.

[@paliszarok]

Awesome. Could you make a video about gdb?

[@nirlichtman]

Yes, planned :)

[@guilherme5094]

👍Great!

[@TunifyBasic]

what about services/pidfiles(lockfiles)/daemons idk much about this.

[@spxnr]

Nice. I’m noob, why would it be useful to make a custom system call in the kernel? Wouldn’t the program in user mode be able to do anything with the current system calls?

[@int32_]

you don't need to add a syscall most of the time, but if you're already adding features to the kernel, you might want to add a syscall to use that feature from userspace

[@kinershah464]

Nice video, very informative. I am curious to know what is ramfs and cpio? What is newc?

[@nirlichtman]

Thanks! Checkout my video about making a minimal Linux distro for more information about these questions

[@angelcaru]

SYS_leftpad when?

[@justlyx_0772]

How is it possible to use windows with i3 as in the video?

[@nirlichtman]

I am using a port of Suckless dwm for Windows, more information in the welcome link on my channel

[@justlyx_0772]

@@nirlichtman oh, I didn't know it was possible for windows, the video is awesome by the way keep that great content up!

[@ahmedsaed26]

Amazing Content!

[@electrolyteorb]

Just casually adding syscalls to kernel... Yeah seems about right

[@mzakyr42]

still waiting the linux graphical.
hey how can i make a libc like gnu or musl

[@daniel01045]

מפתיע שאין לך מבטא ישראלי כבד. מקנא

[@nirlichtman]

תודה :) מארה"ב במקור