Important. How to build SRPM packages into binary packages, possibly with patches and modifications. Though I’ve done this before with Debian distributions, I’ve never done it before with CentOS/Fedora/Red Hat.
20160926/https://wiki.centos.org/HowTos/RebuildSRPM
More useful notes.
How to create patches on top of base sources.
20180403/DuckDuckGo rpm spec patches
20180403/http://wiki.networksecuritytoolkit.org/index.php/HowTo_Create_A_Patch_File_For_A_RPM
Only for very basic use cases, not “official-style” kernel modules: how to create kernel module packages.
20180403/DuckDuckGo rpm spec linux kernel module
20180403/http://karuppuswamy.com/wordpress/2008/09/03/creating-a-kernel-module-rpm-package/
Also, that page has some links to some interesting other pages on electronics gadgets to “play with,” i.e. program.