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This project is a custom, monolithic operating system kernel designed specifically for the Raspberry Pi Pico (RP2040) and the newer RP2350 microcontrollers. Written primarily in ARM Assembly to maximize low-level control and serve as an educational deep-dive into OS architecture, it implements core features like dynamic memory allocation, a custom libc, preemptive multitasking, and a POSIX-influenced syscall interface.
I also engineered a custom GeT Computer PCB, available here.
| Feature | Status | Notes |
|---|---|---|
| Dynamic memory allocation | ✅ | Modified Linked-List allocator |
| Custom LIBC | ✅ | For kernel and userspace |
| Multitasking | ✅ | Pre-emptive task scheduler |
| POSIX-like syscalls | ✅ | List of syscalls |
| Filesystem | ✅ | Virtual Filessystem structure and RAMFS |
| Networking | ✅ | Raw sockets, TCP client and server |
| EXT2 support | 🚧 | Planned |
| Multithreading | 🚧 | In progress |
| Custom C compiler and assembler for userspace | 🚧 | In progress |
| Driver | Status | Notes |
|---|---|---|
| PS/2 keyboard driver | ✅ | Both immediate and parallel interfaces (with shift-registers) |
| UART communication | ✅ | |
| VGA driver (640x480) | ✅ | Scaling up resolutions is in progress |
| SD card driver | ✅ | Requires additional error checks and refactoring |
| Ethernet (WIZnet W5100S) | ✅ | Raw sockets, TCP client and server |
- Porting LIBC to user space programs as a dynamic library
- Extending shell and writing user-space programs like vim-like editor
- Introducing Rust into kernel
- ELF executable support
- Memory Protection
- After full filesystem support move some parts of firmware into bootloader. The kernel and the initramfs should reside
in the
/bootdirectory
- ARM GCC toolchain (
arm-none-eabi-gcc) - CMake
git clone https://github.com/atwardzik/os_kernel.git
cd os_kernel
cmake -DCMAKE_EXPORT_COMMANDS=ON -DARCH_RP2350=1 -B build
cd build
make -j4Depending on your needs you should choose -DARCH_RP2040=1 or -DARCH_RP2350=1.
Issues and pull requests are welcome! Please open an issue before starting major work.
There are also issues you can choose from. Some of them are marked as "good first issue" – they require little to no knowledge of kernel internals, but often are important for the stability of the system.
This project uses a .clang-format configuration file to enforce consistent
formatting.
Before submitting a pull request, please format your code using clang-format.
Open-source and released under the BSD 3-Clause License. Feel free to use, modify, and distribute the code in accordance with the terms specified in the license.
Copyright (C) 2024-2026 Artur Twardzik