Markus Maiwald
|
232a97272f
|
Phase 31.2: The Identity Switch (Sv39 Virtual Memory)
THE CROSSING - COMPLETE
========================
Successfully transitioned from Physical to Virtual addressing using
Sv39 page tables. The kernel now operates in a fully virtualized
address space with identity mapping (VA=PA).
ARCHITECTURE
------------
1. Sv39 Page Table Infrastructure (hal/mm.zig):
- 3-level page tables (512 entries per level)
- 4KB pages with proper PTE bit packing
- Bump allocator for page table allocation
- map_page/map_range for flexible mapping
2. Kernel Identity Map:
- DRAM: 0x80000000-0x88000000 (RWX)
- UART: 0x10000000 (RW)
- VirtIO MMIO: 0x10001000-0x10009000 (RW)
- VirtIO PCI: 0x30000000-0x40000000 (RW)
- VirtIO BARs: 0x40000000-0x50000000 (RW)
- PLIC: 0x0c000000-0x0c400000 (RW)
3. Boot Sequence Integration:
- mm_init(): Initialize page allocator
- mm_enable_kernel_paging(): Build identity map, activate SATP
- Transparent transition - no code changes required
THE MOMENT OF TRUTH
-------------------
[MM] Building Sv39 Page Tables...
[MM] Activating Identity Map...
[MM] ✓ Virtual Memory Active. Reality is Virtual.
System continued operation seamlessly:
✓ VirtIO Block initialized
✓ SFS filesystem mounted
✓ GPU probe completed
✓ All MMIO regions accessible
STRATEGIC ACHIEVEMENT
---------------------
This is the foundation for The Glass Cage (Phase 31.3).
We can now create restricted page tables for worker fibers,
enforcing true memory isolation without MMU context switches.
Files:
- core/rumpk/hal/mm.zig: Complete Sv39 implementation
- core/rumpk/core/kernel.nim: Boot integration
- src/nexus/builder/kernel.nim: Build system integration
Next: Phase 31.3 - Worker Isolation (Restricted Page Tables)
Build: Validated on RISC-V (rumpk-riscv64.elf)
Status: Production-ready - The Sovereign ascends to Virtual Reality
|
2026-01-02 15:24:32 +01:00 |