This is a simple x86 32 bit operating system written from scratch, based on Carlos Fenollosas OS tutorial. It contains the following components:

1. Boot loader
2. Operating system kernel, including
   1. ISRs to handle CPU interrupts
   2. VGA driver
   3. Keyboard driver
   4. Shell
   5. Dynamic memory allocation

brew install qemu nasm

https://github.com/lordmilko/i686-elf-tools#mac-os-x

brew install i386-elf-binutils
brew install i386-elf-gcc
brew install i386-elf-gdb

export PATH="/usr/local/Cellar/x86_64-elf-binutils/<version>/bin/:/usr/local/Cellar/x86_64-elf-gcc/<version>/bin/:/usr/local/Cellar/i386-elf-gdb/<version>/bin:$PATH"

make run

make debug

In GDB shell:

• Set breakpoint at function (e.g. start_kernel): b start_kernel
• Start execution: c
• Jump to next instruction: n
• Print variable: p <variable_name>

• Writing a Simple Operating System — from Scratch
• OS Dev Wiki
• JamesM's Kernel Development Tutorials
• BrokenThorn Entertainment's Operating System Development Series
• The Little Book About OS Development
• C Memory Allocation Functions