Georgios

Georgios (Greek for George, said like GORE-GEE-OS) is an operating system I'm making for fun which currently targets i386/IA-32. The purpose of this project is to serve as a learning experience.

Georgios is so simplistic right that now the most impressive application is a snake clone. This is probably going to be the case until applications can be ported.

Features

Working on at least some minimal level

• Kernel console that supports UTF-8 (specifically the subset needed for Code page 437 subset) and some basic ANSI escape codes
• Ext2 filesystem accessed using an ATA Driver (All read only for now)
• Basic preemptive multitasking between processes that can be loaded from ELF files
• ACPI shutdown (thanks in part to ACPICA)

Started on, but not really working yet

• A graphics mode using VESA BIOS Extensions (VBE)
  • This makes use of libx86emu to invoke the BIOS code required to access VBE.
• USB 2.0 stack
• Porting real applications written in Zig and C
  • The applications currently written in Zig are "real", but are using the freestanding target and are using system calls directly. To be able to use a Zig or C hello world program without any modification, the standard libraries would have to be ported and toolchains would have to be modified to target Georgios properly.
• Freeing the OS from the need of a boot CD

Building

Building Georgios requires a Unix-like environment with:

• Zig 0.9.1
• Python 3
• GRUB2
  • Requires i686 Support (grub-pc-bin package on Ubuntu)
• xorriso (xorriso package on Ubuntu)

Georgios can be built as a bootable ISO (called georgios.iso) by running make. If installed, QEMU and Bochs can be run by running make qemu or make bochs respectively. On Ubuntu, Bochs requires apt-get install bochs bochsbios bochs-sdl bochs-x vgabios.

For the moment it assumes the existence of an IDE disk with certain files on it.

Resources Used

• OSDev Wiki
  • Very popular, fairly large set of resources in one place, but rough or just plain unhelpful in many places.
• The little book about OS development
  • Polished, but limited intro into x86 OS development. Provided me with the initial start.
• Intel x86 Software Development Manuals
• xv6
• The Design and Implementation of the 4.4 BSD Operating System
• FYSOS: Media Storage Devices