Notes about learning OS dev: [1] A minimal kernel Below are list of references that I used to learn A minimal Multiboot Kernel HelloOS What is the minimal setting/configuration we need to have so we can boot a minimal kernel? Assuming we are using GRUB boot loader, it seems to me we need to have 4 files to be able to boot a minimal kernel. … ├── Makefile └── src └── arch └── x86_64 ├── multiboot_header.asm ├── boot.asm ├── linker.ld └── grub.cfg Let’s go through these files one by one. multiboot_header.asm To know what is this, we need to know how boot works.