Re: Source of the source ?
So, you wanna build a distro… You’ll need to interface with BIOS/UEFI perhaps GRUB2 is a good choice - source code on GitHub (a few different flavours/repos). You’ll need some sort of filesystem wrangler LLVM is a good choice (GitHub). You’ll need a kernel - again either kernel archive or GitHub. You’ll need a compiler and tool chain to build the source code for the hardware you want it to run on- clang and GCC is a decent choice (GitHub) and a base clibrary like glibc which is available from ftp or from gnu git repo. Then you probably want to think about an init system - sysv (several places) or systemd (GitHub) are commonly used choices. Then some utilities like common GNU utilities like ls, cd, cat (gnu svn or ftp). Some package manager like rpm or deb and a means to pull and manage such as yum dnf or apt (various repos including GitHub). Probably pick a shell (BASH being a solid choice - gnu.org repos). Pick (or not) a means to provide a GUI, lots of choices (westland/gnome etc etc). You’ll want some scripts to lash some things together and provide config files and bits and bobs (you’ll want a text editor such as nano (gnu git) or vim (or… emacs if you are a wizard). You want ti include applications such as OpenSSH (loads of ftp mirrors). Once you’ve collected all the components you can package them together and host them, or link to them. You probably also want some infrastructure to host all the packages at versions you support in a location accessible to your package manager. Now you have a distro and means to provide s/w packages to it. It’s ALL open source, all of it. There’s also nothing stopping you from including what folk refer to as ‘binary blobs’ (proprietary, precompiled code usually for hardware interfaces) - provided you (as the distro provider) sort out an agreement with the owner/license holder. Once your operating system environment is up and running, Your user is plenty able to install compiled code such as paid-for closed source s/w of which there is plenty!
Now, let’s say that you are really good at testing all the combinations of the software that you include against all the hardware configurations you support. And let’s say that your customers appreciate the ability to call you up, or to have you investigate some problem, or support some bit of hardware - that sounds like something that you could charge for as a service, or a one-off fee for ‘providing’ the distro. That’s what companies like Ubuntu and Redhat offer (Ubuntu also provide the s/w without support, which is jolly decent of them). Or, you could provide all this hard work ‘for free’ in return for access to other peoples hard work, or simply because you like the idea of contributing something into the world that other people may find useful.
Will that do for a link?