Show HN: Anos – a hand-written ~100KiB microkernel for x86-64 and RISC-V

Summary

anos - An Operating System 💾 NoteThis is not yet an operating system, but definitely has reached "toy kernel" status, since it now supports user mode preemptive multitasking on up to 16 CPUs, provides enough kernel support to run functioning device drivers in userspace, and runs on real hardware 🥳. Anos is a modern, opinionated, non-POSIX operating system (just a hobby, won't be big and professional like GNU-Linux®) for x86_64 PCs and RISC-V machines. Anos currently comprises the STAGE3 microkernel, SYSTEM user-mode supervisor, and a base set of servers implementing the base of the operating system. There is a (WIP) toolchain for Anos based on Binutils, GCC (16-experimental) and Newlib (with a custom libgloss). Anos is free software licensed under the GPLv2, with similar linkage exceptions as other major free operating systems. TL;DR / Headline features Non-zealous microkernel ("STAGE3") with scheduling, memory management, and IPC primitives Strict system-wide capability-based security model User-space system management server ("SYSTEM") provides common OS abstractions User-space ACPI or Devicetree-based hardware discovery and driver model (WIP) Custom software-development toolchain (based on binutils, GCC and Newlib) Requirements (theoretical min/max): 1 core, 256MiB RAM / 16 cores, 127TiB RAM Kernel Design (WIP, subject to change) As far as the Kernel is concerned, there's much to still be decided, and most of what has been decided could still change without notice. Since this is being designed as 64-bit from the beginning, there's a lot of things I can do that I wouldn't otherwise be able to, and I'm experimenting with a few different ideas. Decisions I've taken so far are, briefly: Non-zealous microkernel providing only: Bare-minimum drivers for hardware used in the kernel itself CPU (both x86_64 and RISC-V) Basic timers (HPET, TSC, SBI Timers on RISC-V) Interrupts (LAPIC, MSI / MSI-X, S-mode interrupts) Physical / virtual memory management (48-bit on both archi...