So, I jut started learning about the Linux kernel. I have setup a GDB environment and want to learn more about the system internals of the kernel. Basically, I am interested in taking apart the the machine and putting it back together. All while understanding what is going on internally. Any advice for someone like me? Somebody who wants to learn how the kernel works. Is GDB even necessary?

Thanks guys, you all have been lifesaver for me.

-E

Kernel is the OS. I suggest you get acquainted with it first. IMHO the best way to do it is getting sources and then starting with minimal configuration 'make allnocnfig'. From there start adding options and functions until you have a working kernel, read up on every option, don't rush. Then you will have vital knowledge of kernel structure and functionality and can start diving deeper.

alright, that sounds good. ill start doing that.

> understanding everything, from the *very bottom up*!!!

Sounds like me, although I'm barely 2% of the way along the full Journey.

My idea is two directions:
1) study documentation on the syscalls and use strace (man 2 intro)
I think you would want to understand what the kernel is and does, before you start to build/configure/modify it

Then 2) the 7,500 CONFIG_ options See the book Linux kernel Programming, pages 66-172

Here's my dream goal: (BTW, do you use VirtualBox?)
https://www.linuxquestions.org/quest...ne-4175716205/

I am using Qemu at the moment. Yeah I am in a similar situation. I am daunted by the all the config options.

Go get a book - which one depends on what you intend to do/learn. The kernel is ridiculously dynamic - just look at the patchlist for each release. Any book you get is instantly out of date, but will be useful none-the-less.
I haven't looked recently, but let's say in round numbers the kernel is 25 million (yep, you read that right) lines of code. Pick something that interests you and concentrate on that - could be scheduler, block device drivers, swap, memory management, boot, whatever. Whatever you pick will be getting updates all the time, which can be bloody frustrating when you are trying to learn the code. Stick with it.

As it happens there are now some really quite good tracing tools for the kernel that make life much easier to get involved without knowing all the gory details of the code - I couldn't believe my luck when BPF became available.

There is extensive documentation at kernel.org.

Tip: You need to go thru all options and when you are finished you have to repeat, during first round you enabled options and these made more options visible. And then third round. After third you should have a working kernel.

You didn't think you can get it done in one afternoon, did you?

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