OS Development from Scratch

Purpose

Guide agents through building a minimal operating system from scratch: bootloader stages (BIOS/GRUB vs UEFI/limine), 64-bit long mode setup with GDT and page tables, IDT and interrupt handlers, PIC/APIC configuration, basic keyboard and serial drivers, physical and virtual memory managers, context switching, with xv6-RISC-V as a reference architecture.

When to Use

• Learning how an OS boots from power-on to main()
• Implementing protected/long mode transitions on x86-64
• Writing a physical memory allocator (bitmap) and page table manager
• Handling timer, keyboard, and page fault interrupts
• Testing with QEMU -kernel and cross-compiler x86_64-elf-gcc
• Porting concepts from xv6 to a custom x86 or RISC-V kernel

Workflow

1. Boot stages overview