Cross-compiling under arm and kernel sources?

Question

linux

I couldn't use Google in English, please explain in Russian if possible. When using utilities like crosstool-ng to compile utilities like tcpdump on the host system, how important is it to have targetOS kernel sources available when building the toolchain, if this is a custom OpenWRT kernel (I know about the OpenWRT SDK, thanks). I am not an expert in this matter, just about two years ago, I managed to compile an open-source driver for one of the custom Android builds only after I found the source codes for the kernel of the target system. But there was still ko, Android and my crooked hands, maybe with utilities for embedded devices there is a chance to get by with source codes from https://www.kernel.org/ without hard binding to custom kernels? Or is the process of creating linux headers so specific?

Thank you!

Answer 1

Or is the process of creating linux headers so specific?

No. The userspace interface of the kernel does its best to maintain backward compatibility. Those. if you build a toolchain using the headers of some kernel version, the binaries built by it will work (and if they don’t, then there is reason to report it as a kernel bug) on ​​newer kernels.