In an attempt to learn how to write an operating system and to relive the nostalgia of tinkering with Delphi as a kid, I have decided to begin writing an operating system in Object Pascal. This is simply a toy project to work on when I am bored.

Despite having "OS" in the name, PascalOS is far from an operating system right now. Here's a summary of what is and isn't currently implemented:

• Boot to kernel entrypoint
• Basic GDT setup
• Bare-minimum IDT setup and ISR handling
• Bare-minimum IRQ handling
• Keyboard support
• Virtual memeory (paging)
• Dynamic memory allocation
• Filesystem support
• Multitasking
• User mode
• Everything else

WARNING: The current Makefile makes some pretty strong assumptions about your build environment and is NOT portable. I am developing PascalOS inside a 32-bit Debian 10 virtual machine because I am too lazy to set up proper cross compilation. To set up a development environment on Debian, run the following command to install all necessary packages (I might be forgetting some):

sudo apt install build-essential fpc git qemu-system-i386

If for some reason you still want to build this, you can like so:

git clone https://github.com/jonpalmisc/PascalOS.git
cd PascalOS
make iso

To run the OS after building the ISO, use the included run targets:

make runb # to run with Bochs; or
make runq # to run with QEMU

This project would not have been possible without the following resources:

• The OSDev Wiki
• James Molloy's Kernel Development Tutorials
• Bran's Kernel Development Tutorials

This project is licensed under the Mozilla Public License v2. For more information, see the LICENSE.txt file.