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.
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, version, shutdown, reboot.
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.
The supported compilers are:
- Clang. When compiling with Clang, one can use the toolchain file
cmake/cross-compile-toolchains/x86_64-uefi-clang-generic.cmake. - MinGW cross-compiler.
cmake/cross-compile-toolchains/x86_64-w64-mingw32-generic.cmakeis the toolchain file you can use to easily cross-compile the code on Linux if you have MinGW installed.
You can use CMake directly or execute either build-clang.bash or build-mingw.bash script if you're running Linux. The scripts will also generate a VM disk image by executing generate-img.bash
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-img.bash script to generate a disk image that you can run under QEMU.
- GNU EFI (bundled with the project itself in
third-party/gnu-efi-code),
- Either Clang or MinGW cross-compiler,
- CMake build system.
mtoolsfor generating disk images for VMs.