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SharpMetal v1.0.0 — Freestanding C# Bare-Metal Microkernel

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@Sadik00789 Sadik00789 released this 07 Sep 09:27
· 26 commits to main since this release
v1.0.0
a55b075

SharpMetal v1.0.0: 12-Layer Bare-Metal x86-64 Microkernel in Freestanding C#

Initial production release of SharpMetal, an seL4-inspired microkernel operating system written in freestanding C# (.NET 9 Native AOT) for modern x86-64 hardware with zero dependencies on CoreCLR, glibc, or external bootloaders.

Architectural Highlights

  • Freestanding Native AOT: Zero CoreCLR/Mono runtime dependencies; executes directly on bare metal using a custom MiniCoreLib with unmanaged entry points and zero GC statics.
  • seL4-Style Capability Model & CDT: Guarded CSpace tables with a zero-alloc Capability Derivation Tree (CDT) enforcing recursive capability revocation, synchronous PTE cleardown, and TLB shootdown (invlpg).
  • Synchronous IPC & Timeslice Donation: Fast-path register-based rendezvous IPC with timeslice donation, 64-bit atomic notifications, and unified dual-wait reactors (sys_recv_any).
  • Interrupt-Driven Ring 3 Drivers: Isolated userland drivers for NVMe DMA block storage and modern VirtIO-Net driven via explicit PCI MSI/MSI-X vectors (0x30 and 0x31) instead of polling.
  • Dynamic ZeroAlloc Arena: Chunk-linked NativeArena expansion (ArenaChunk) in Userland.Runtime.ZeroAlloc mapped at high DMA aperture 0x0000_7000_0000_0000UL to prevent driver starvation.
  • Persistent Filesystem & VFS: Complete FAT32 cluster chain parser with System.IO.File streaming abstractions over shared DMA memory.
  • AVX2 Accelerated Compositor: 256-bit SIMD software compositor blitting to UEFI GOP linear video memory using Write-Combining cache attributes and dirty-region clipping.
  • Fault-Tolerant Supervisor: Watchdog-based crash interception, capability revocation, and automated PCIe Function-Level Reset (FLR) driver reincarnation.
  • Interactive Graphic Terminal Shell: Micro-GC userland shell with command history ring buffering, PSF2 font rendering, hardware benchmarking tools, and ACPI shutdown support.

Verification & CI

  • Automated streaming test harness validated under headless QEMU with OVMF firmware, asserting sequential milestones across all 12 layers (CSpace, PCI ECAM, NVMe canary write/read, VirtIO TX ring, FAT32 VFS, and Shell) with clean exit code 0.

Quick Start (Booting under QEMU)

# 1. Download pre-built disk image from release assets
curl -LO https://github.com/sadik00789/SharpMetal/releases/download/v1.0.0/disk.img

# 2. Create backing image for NVMe benchmark storage
qemu-img create -f raw nvme.img 64M

# 3. Launch QEMU with UEFI firmware, NVMe, and VirtIO-Net
qemu-system-x86_64 -machine q35 -cpu max -m 1G \
  -drive if=pflash,format=raw,readonly=on,file=/usr/share/OVMF/OVMF_CODE.fd \
  -drive file=disk.img,format=raw \
  -drive file=nvme.img,format=raw,if=none,id=nvm \
  -device nvme,serial=nvme01,drive=nvm \
  -netdev user,id=net0 -device virtio-net-pci,netdev=net0
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