Anvil kernel. In hard developing...

Architectural Postulate

This project implements a microkernel-based operating system with a strong focus on security and strict isolation.

The kernel and HAL are intentionally kept minimal and are responsible only for tasks that cannot be safely or reasonably delegated to user space.
Any logic that is not fundamental to secure hardware control or execution context management is considered user-level functionality and is implemented as services.

Core Principles

• HAL as the Root of Trust
  The HAL is responsible solely for architecture initialization, isolation, and safe control transfer.
  It contains no policy, has no knowledge of service types, and makes no semantic decisions.

• Strict Kernel ↔ User Boundary
  Transitions between execution modes occur only through formal mechanisms (interrupts, exceptions, syscalls).
  User-mode code never inherits kernel state.

• Virtual Memory as a Security Primitive
  Address spaces are isolated by hardware.
  Services cannot access kernel memory or each other unless explicitly permitted.

• Interrupts as Events, Not Logic
  Interrupt handling in the kernel is minimal and free of complex logic.
  All decisions about further execution are made centrally and formally.

• User-Mode Services
  File systems, networking, console handling, drivers, and other subsystems run outside the kernel and interact with it through well-defined interfaces.

• Minimal and Auditable Design
  Kernel and HAL code are designed to be:

  • small
  • deterministic
  • easy to audit
  • suitable for future formal verification

Goal

The goal of this project is not maximum performance at any cost, but predictability, isolation, and architectural clarity, enabling the construction of a reliable system on top of a minimal trusted kernel.

If functionality can be safely implemented in user space, it does not belong in the kernel.

syscalls

thread_exit thread_sleep - done

tcb_configure tcb_set_regs tcb_resume tcb_suspend tcb_read_regs

invoke recv reply reply_recv

cnode_copy cnode_move cnode_delete cnode_revoke

frame_alloc - done vma_map - done vma_unmap - done mprotect - done

notify_signal notify_wait notify_poll

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