How Does Linux Boot Process Work?

thanks

Excellent demo

Great descriptions... 😊

systemd-boot is great. No fuss just straight to the point !

Anyone.. Which software is used to make this video (animations)?

Technically, this is not the linux boot process as initramfs is part of it and not mentioned.

very nice video... loved it...

KUDOS! I've never seen such nicer explanation for this.

The information density here is very high

Well done!

Great overview. I think is good background info for any OS.

And imagine that systemd was initially implemented by a single guy named Lennart Poettering.

I thought systemd was great until I started using OpenRC. Thanks for the video, nice summary!

It is possible to use gpt partitions without needing UEFI. Even old motherboards with intel 775 socket will boot using gpt partitions without UEFI:

"Yes, it is possible to use GPT (GUID Partition Table) partitions without UEFI (Unified Extensible Firmware Interface). GPT is a partitioning scheme for formatting and partitioning hard drives, and it's independent of the firmware interface being used (UEFI or BIOS).

However, the ability to boot from a GPT-partitioned disk depends on the firmware of your system. Most modern systems use UEFI firmware to boot, and UEFI is compatible with both GPT and the older MBR (Master Boot Record) partitioning scheme.

If your system uses the older BIOS (Basic Input/Output System) firmware instead of UEFI, it may have limitations when it comes to booting from GPT disks. Some BIOS systems can boot from GPT disks using a compatibility support module (CSM), while others may not support GPT booting at all.

So, in summary, while you can use GPT partitions without UEFI, the ability to boot from a GPT disk depends on the firmware capabilities of your system."

Does it still take ages (like 5-10 minutes) to start a Linux computer?
I haven't tried since 2003, when I gave up on Linux.

But on the other hand, Windows was almost as embarrassingly slow too at the time.
To me, a computer intended for consumers should start in a second or less, quite literally. Just like a calculator.

So much nitpicking in the comments. I guess this is what happens when you try to teach linux users lol. Nice overview. Could be a nice quick ref for users.

With how short the common attention span is I think this is a nice start for people trying to learn more about linux.

Thank you

Very nice.

GRUB2 can be replaced by SystemD-boot too...

Great visualization of the entire boot process, Thank you.

good material.. ByteByteGo! keep it up!

Awsome, great job. thanks a lot for your time. excellent explanation!

I think this video could have extended itself to include the graphical boot process. The display manager which boots up the desktop environment.

How buggy systemd muddied/destroyed Linux.

I bought your books 📚, but haven't had time to read, by I hope I will do soon.

this is awesome, the same core idea when develop embedded firmware as well

how do do you do these animations? its nice and clean!

Power on karne tak to samajh aaya, chalo bios tak bhi theek hi tha par fir uske baad kuch samajh nahi aaya sasur ji.

top screenshot is irrelevant on the kernel loading step

In my experience most BIOS implementations boots faster than UEFI ones.

It depends on implementation, not the technology.

Content I liked

No way. I just guessed it right. I told exact same on my interview 😂.

which system? which linux?

This was excellent, well done.

🤯

I hated systemd when my distro first started using it, but now i think its much better than system V

thanks for the explanation! this helps!

"gwid" 😬

Can you do s video like that but about templeOS?

"Their greatest fear is that somewhere, somewhere, someone is having fun..."

These 'abolitionists' have no respect or esteem for women. The women need to be saved from themselves, because they are not fully volitional? Nonsense. At the core of this nonsense is womens' fear of loss of control of sex. Why would a man submit to the sexual manipulation that women so blithly wield, if it is available commercially?

People just need to mind their own business. More resources should be made available for mental health care, so these whiny idiots can work out their problems without imposing them on others...

As has already been said, there is a lot going on in each of these steps.

My major criticism is that step 5 simplifies away the usual mechanism of running some code from an initial ramdisk: this is done so that the kernel does not have to contain all the device drivers needed to load whatever modules it needs before the final root partition becomes readable.

That also means that an earlier step needed to load the initial ram disk into memory and tell the kernel where to find it. Grub (or some other boot program like Lilo) will have done this already, so the Grub step should mention that it loads a filesystem containing drivers as well as libraries into ram before passing control to the kernel.

And then, in my opinion, you need an extra step between 4 and 5 for the initial ram stage, that is used to get the system able to actually read the code it needs off the disks. While it does that the kernel only needs to know how to read the initial ramdisk.

More detail follows...

There are two exceptions to what i just said

1. If you compile your own kernel you can arrange that the kernel has all the drivers it needs built in (Gentoo users might do this, knowing in advance exactly what filesystem and hardware will hold the operating system)

2. Puppy (and most Live Disk systems) boot into the ramdisk and never leave it.

For different reasons, both these exceptions slow down system loading (because either the kernel or the ramdisk is huge) but often speeds up running once the boot is complete because the kernel has what it needs in memory at all times, one way or another.

The main problem with this video, and I don't want to be too critical, is that there's no real-depth in what is going on. Firstly the explanation about the BIOS and POST etc has nothing to do with Linux. That's the hardware initializing itself for the booting of an operating system. The video should have focused from this moment onwards and gone into the details.

Would be interesting to know how and why BIOS is slower to boot than UEFI.

Very lovely & professional made <3

when I push power button in Linux machine I went into Trance

Using Slackware, no systemd.

we dont use systemd where i live. only dinit

Excellent presentation and narration; whats' used for your animations?

This is very general information and explaining how x86 boot itself works is just a waste of time.