Use --depth 1 when using git clone, because the actual size of this repo is ~50mb. Without it, you will clone like ~200mb! If you care about internet bandwidth or speed, clone like this (an example):
git clone https://github.com/NTSP3/MarkedRain.git --depth=1
The "MarkedRain" is a new linux OS that uses buildroot with OpenRC as init. It is really easy to work with. There was an older system based on Os2020, but working with nothing proved difficult.
Install dependencies for 'make' & 'menuconfig', then run "make menuconfig". Configure as per you desire, then you can either do "make" on the root directory, or go to "source/buildroot" and run menuconfig there, to configure its options, and then run "make" on the root directory, not on buildroot's directory.
View "docs/building.md" for other make options.
