BIOS TO KERNEL

​What actually happens between powering on a machine and running your own code?

​In this live session, we build a minimal operating system from scratch — starting from a custom bootloader and ending with a kernel that directly interacts with hardware.

​What We Will Build

​A 16-bit bootloader loaded at 0x7C00

​A disk loader that reads raw sectors

​Transition from real mode to protected mode

​A 32-bit kernel written in C

​Direct screen output via VGA memory (0xB8000)

​A keyboard driver using interrupts

​A simple memory allocator

​What You Will Learn

​How machines boot from firmware to your code

​How to run programs without any runtime

​How CPUs switch execution modes

​How to communicate directly with hardware

​The core building blocks of operating systems

​Key Concepts

​Boot sector and memory layout

​Real Mode vs Protected Mode

​Global Descriptor Table (GDT)

​Interrupt Descriptor Table (IDT)

​Hardware interrupts (IRQ)

​Memory-mapped I/O

​Basic memory management

​Technologies Used

​x86 Assembly (NASM)

​C (freestanding, no standard library)

​BIOS interrupts (int 0x10, int 0x13)

​QEMU (emulation)

​GCC and LD

​Live Demo Highlights

​Booting from a raw disk image

​Switching CPU modes live

​Printing text via direct memory access

​Keyboard input handled by interrupts

​Building a memory allocator from scratch

​Who Should Attend

​Systems programmers

​Low-level developers

​Kernel enthusiasts

​Compiler builders

​Anyone curious about how computers work

​Prerequisites

​Basic programming knowledge

​Curiosity about how machines work

​Closing Hook

​We start with a blank disk.

​We end with a working kernel.