How can the Linux kernel compile itself?

Question

I don\'t quite understand the compiling process of the Linux kernel when I install a Linux system on my machine.

Here are some things that confused me:

Answer 1

It's not turtles all the way down. Just like you say, you can't compile an operating system that has never been compiled before on a system that's running that operating system. Similarly, at least the very first build of a compiler must be done on another compiler (and usually some subsequent builds too, if that first build turns out not to be able to compile its own source code just yet).

I think the very first Linux kernels were compiled on a Minix box, though I'm not certain about that. GCC was available at the time. One of the very early goals of many operating systems is to run a compiler well enough to compile their own source code. Going further, the first compiler was almost certainly written in assembly language. The first assemblers were written by those poor folks who had to write in raw machine code.

You may want to check out the Linux From Scratch project. You actually build two systems in the book: a "temporary system" that is built on a system you didn't build yourself, and then the "LFS system" that is built on your temporary system. The way the book is currently written, you actually build the temporary system on another Linux box, but in theory you could adapt it to build the temporary system on a completely different OS.