On Tue, 17 Nov 2020 14:37:00 +0900, ckim@etri.re.kr said:

> Some years ago, I used to use sparc-ab-elf- to build linux kernel.

That will probably build a kernel for the Sun SPARC architecture...

> Recently, I found a website that I should use aarch64-linux-gnu tool to
> build the kernel.
>
> I tried following it and it generated vmlinux file. (I can't find the web
> page link, but I'm sure I wrote that procedure down when I built vmlinux)

That vmlinux file will only be useful for a 64-bit ARM architecture.

What sort of machine are you going to run the newly built kernel on,
and what sort of machine are you using for the build?

(If you're building on the system you'll be booting it on, the distro's gcc and make
commands should be sufficient)