xsspark / dexpros

An experimental x86-64 operating system.

DexprOS

A simple operating system for x86-64 UEFI machines written in C and assembly. Made as an experiment to see if I could actually develop something so low-level as an OS.

What is it capable of?

For now, DexprOS is able to:

• setup graphics using UEFI Graphics Output Protocol,
• exit UEFI boot services,
• set up its own 4-level or 5-level page map,
• load a working General Descriptor Table and Interrupt Descriptor Table,
• setup PIC (Programmable Interrupt Controller) and PS/2 controller,
• handle keyboard input and convert it to unicode characters,
• process a few commands in a simple shell: echo, clear, help, shutdown, reboot.

Planned features

As DexprOS is just an experiment and my focus goes mainly to other projects, new features may be introduced slowly over time.
Here are my upcoming plans:

• memory allocation,
• syscalls,
• userspace code execution,
• parsing some ACPI structures.

Compiling

The only officially supported compiler is 64-bit MinGW. Within the cmake/cross-compile-toolchains directory, there is a CMake Toolchain file to easily cross-compile the code on Linux if you have MinGW installed.
You can use CMake directly or execute the build.bash script if you're running Linux.

Running

To run on real hardware, create a bootable FAT32 partition on a USB drive. Then copy the BOOTX64.EFI file from your build directory to /EFI/BOOT/BOOTX64.EFI on your USB.

You can also use the generate-iso.bash script to generate a disk image that you can run under QEMU.

Dependencies

Code:

• GNU EFI (bundled with the project itself in third-party/gnu-efi-code),

Building:

• MinGW compiler,
• CMake build system.