Markus Maiwald
a0ac0ddb64
feat(rumpk): Achieve interactive Mksh shell & formalize Sovereign FSH
...
CHECKPOINT 7: Nuke LwIP, Fix Stack
🎯 PRIMARY ACHIEVEMENTS:
- ✅ Interactive Mksh shell successfully boots and accepts input
- ✅ Kernel-side LwIP networking disabled (moved to userland intent)
- ✅ C-ABI handover fully operational (argc, argv, environ)
- ✅ SPEC-130: Sovereign Filesystem Hierarchy formalized
🔧 KERNEL FIXES:
1. **Nuked Kernel LwIP**
- Disabled membrane_init() in kernel.nim
- Prevented automatic DHCP/IP acquisition
- Network stack deferred to userland control
2. **Fixed C-ABI Stack Handover**
- Updated rumpk_enter_userland signature: (entry, argc, argv, sp)
- Kernel prepares userland stack at 0x8FFFFFE0 (top of user RAM)
- Stack layout: [argc][argv[0]][argv[1]=NULL][envp[0]=NULL][string data]
- Preserved kernel-passed arguments through subject_entry.S
3. **Fixed Trap Return Stack Switching**
- Added sscratch swap before sret in entry_riscv.zig
- Properly restores user stack and preserves kernel stack pointer
- Fixes post-syscall instruction page fault
4. **Rebuilt Mksh with Fixed Runtime**
- subject_entry.S no longer zeros a0/a1
- Arguments flow: Kernel -> switch.S -> subject_entry.S -> main()
📐 ARCHITECTURAL SPECS:
- **SPEC-130: Sovereign Filesystem Hierarchy**
- Tri-State (+1) Storage Model: /sysro, /etc, /run, /state
- Declarative Stateless Doctrine (inspired by Clear Linux/Silverblue)
- Ghost Writer Pattern: KDL recipes -> /etc generation
- Bind-Mount Strategy for legacy app grafting
- Database Contract for /state (transactional, encrypted)
🛠️ DEVELOPER EXPERIENCE:
- Fixed filesystem.nim to fallback to .nexus/ for local builds
- Prevents permission errors during development
🧪 VERIFICATION:
Syscalls confirmed working: write (0x200, 0x204), read (0x203)
NEXT: Implement proper TTY/PTY subsystem for full job control
Co-authored-by: Forge <voxis@nexus-os.org>
2026-01-05 01:14:24 +01:00
Markus Maiwald
3b755cac06
feat(rumpk): First successful Zig+Nim boot on QEMU ARM64
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THE RUBICON IS CROSSED
======================
Rumpk v0.1 successfully boots on QEMU ARM64 virt machine.
Zig L0 initializes HAL and hands off to Nim L1.
BOOT OUTPUT
-----------
[Rumpk L0] Stack: 16KB @ stack_bytes
[Rumpk L0] UART: 0x09000000 (QEMU virt)
[Rumpk L0] Handing off to Nim L1...
[Rumpk L1] Memory: ARC (Deterministic)
[Rumpk L1] POSIX: None (Hostile)
[Rumpk L1] Status: OPERATIONAL
[Rumpk L1] The Rubicon is crossed.
[Rumpk L1] Zig + Nim = Sovereign Metal.
IMPLEMENTATION
--------------
Layer 0 (Zig):
- hal/main.zig: Naked _start, stack setup, zig_entry
- hal/uart.zig: PL011 UART driver for QEMU virt
Layer 1 (Nim):
- core/kernel.nim: kmain() entry, FFI imports from Zig
- Compiled with --mm:arc --os:any for freestanding
Glue (C Stubs):
- core/include/: string.h, stdio.h, stdlib.h, signal.h, etc.
- core/cstubs.c: memcpy, memset, strlen, printf, exit stubs
- Provides minimal libc for Nim's generated C code
Build System:
- build.sh: Orchestrates Zig build-obj + Nim c + zig cc link
- run.sh: QEMU launch script
- boot/linker.ld: ARM64 linker script at 0x40080000
VERIFICATION
------------
$ qemu-system-aarch64 -M virt -cpu cortex-a57 -nographic -kernel build/rumpk.elf
→ Successfully prints L0 and L1 banners
→ Enters idle loop (wfi instruction)
NEXT STEPS
----------
Phase 2: Simple bump allocator for Nim heap
Phase 3: Two-fiber context switch (Ping/Pong)
Phase 4: NPL loading with Ed25519 verification
Phase 5: VisionFive 2 RISC-V hardware boot
This proves: POSIX is optional. GCC is optional. Zig + Nim = Sovereign Metal.
2025-12-31 20:18:47 +01:00