Northport is a monolithic kernel, written in C++ and booted via the Limine protocol. It currently supports x86_64 and riscv64 machines. This repo also contains a completely standalone support library (see libs/np-syslib).
Instructions for building it yourself are available here, and a more in-depth manual can be found under the releases tab or by cloning this repository and running make docs.
A brief summary of the current goals and features are listed below, or check the roadmap for a more granular view. Pre-built isos are made available at major feature milestones, but for the latest and greatest it's recommended to build from the master branch.
- To build a usable, extensible and relatively complete kernel. This means an smp-aware scheduler with support for heterogeneous processors, media stacks (graphics, audio and network) and a flexible driver infrastructure.
- Support for multiple architectures: the current targets are x86_64 and riscv64, but this may expand over time.
- Be self hosting, this includes cross compiling the system.
- Clean code and useful documentation.
- Usable on both virtual machines and real hardware.
An extended goal (previously goal #5) is to add a comfortable user experience: a window manager, basic programs like a text editor and file explorer.
Kernel:
- Support for multiple architectures: riscv64, x86_64.
- Memory management:
- PMM with a fast path for single page allocations (freelist), and a slow path for allocations with imposed limits (required by some drivers).
- Modular and portable VMM, with demand paging options for anon and vfs backed memory. Inspired by the old SunOS design.
- General purpose heap provided by slabs for smaller objects and a freelist for larger objects. Slab allocation can be accelerated by core-local caches, and several debug features are available.
- Logging infrastructure: fast and lock-free with support for several early outputs (uart chips, debugcon) and a built-in graphical terminal (based on gterm from the Limine bootloader).
- Panic sequence with stack walker and symbol lookup.
- Global software clock, driven by a number of supported hardware timers: LAPIC, TSC, HPET, PIT, SBI timer.
- SMP-aware scheduler: round robin with per-core queues, work stealing and DPCs.
- VFS with a robust tempfs driver. File contents are sparsely cached in a global file cache.
- Loadable drivers and device management, partially automated by a device tree parser and PCI enumeration.
- Notable drivers include: NVMe, virtio devices.
- Optional UB sanitizer, helpful for detecting bugs or increasing code size!
Build System:
- Uses stock core tools and GNU make, runs anywhere (tm).
- Xorriso is needed for generating bootable isos.
11/10/2023: Kernel panic while loading a malformed driver from the initdisk.
20/11/2022: x86 and riscv kernels running side by side in qemu.
- DreamOS64: another 64-bit OS by one of the northport contributors, Ivan G.
- OSdev notes: a repository of notes about various osdev topics. Feel free to contribute!
This is a complete rewrite of the original. If you're looking for that, it's available on the archive-2022-version branch.