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Author SHA1 Message Date
Markus Maiwald 4cec2d8c25 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:  <voxis@nexus-os.org>
 2026-01-05 01:14:24 +01:00
Markus Maiwald 6e78b7f458 Rumpk Stability, NipBox Boot, and Repository Cleanup 
- Fixed Rumpk RISC-V Trap Handler (SSCRATCH swap, align(4), SUM bit) to prevent double faults.

- Stabilized Userland Transition (fence.i, MMU activation) allowing NipBox execution.

- Restored Forge pipeline to build NipBox from source.

- Documented critical RISC-V trap mechanics in .agent/tips.

- Committed pending repository cleanup (obsolete websites) and new core modules.
 2026-01-04 21:39:06 +01:00
Markus Maiwald 1b4facd86b Phase 37: The Glass Cage - Memory Isolation Complete 
VICTORY: All page faults (Code 12, 13, 15) eliminated. NipBox runs in isolated userspace.

Root Cause Diagnosed:
- Kernel BSS (0x84D5B030) was overwritten by NipBox loading at 0x84000000
- current_fiber corruption caused cascading failures

Strategic Fixes:
1. Relocated NipBox to 0x86000000 (eliminating BSS collision)
2. Expanded DRAM to 256MB, User region to 64MB (accommodating NipBox BSS)
3. Restored Kernel GP register in trap handler (fixing global access)
4. Conditionally excluded ion/memory from userspace builds (removing 2MB pool)
5. Enabled release build optimizations (reducing BSS bloat)

Results:
- Kernel globals: SAFE
- User memory: ISOLATED (Sv39 active)
- Syscalls: OPERATIONAL
- Scheduler: STABLE
- NipBox: ALIVE (waiting for stdin)

Files Modified:
- core/rumpk/apps/linker_user.ld: User region 0x86000000-0x89FFFFFF (64MB)
- core/rumpk/hal/mm.zig: DRAM 256MB, User map 32-256MB
- core/rumpk/hal/entry_riscv.zig: GP reload in trap handler
- core/rumpk/core/ion.nim: Conditional memory export
- core/rumpk/libs/membrane/ion_client.nim: Local type declarations
- core/rumpk/libs/membrane/net_glue.nim: Removed ion import
- core/rumpk/libs/membrane/compositor.nim: Stubbed unused functions
- src/nexus/builder/nipbox.nim: Release build flags

Next: Fix stdin delivery to enable interactive shell.
 2026-01-04 02:03:01 +01:00
Markus Maiwald 2a1af03e28 feat(rumpk): Phase 8 - The Summoning (ELF Loader) - 95% Complete 
## Major Features

### 1. Dynamic ELF64 Binary Loading
- Implemented ELF parser with full header validation (core/loader/elf.nim)
- Created kexec() loader supporting PT_LOAD segment mapping
- Added BSS initialization and data copying from VFS
- Assembly trampoline (rumpk_enter_userland) for userland entry

### 2. Syscall Infrastructure
- Added CMD_SYS_EXEC (0x400) for consciousness swapping
- Integrated exec command in NipBox shell
- Implemented syscall routing through command ring
- Added provenance tracking via SipHash

### 3. Test Binary & Build System
- Created hello.c test program for alien binary execution
- Automated compilation and initrd inclusion in build.sh
- Added libnexus.h header for standalone C programs

### 4. VFS Integration
- Implemented TarFS file cursor system for sequential reads
- Fixed infinite loop bug in cat command
- Added debug logging for VFS mount process

## Technical Improvements

### Memory Management
- Fixed input ring null pointer dereference
- Implemented CMD_ION_FREE syscall for packet reclamation
- Resolved memory leak in input/output pipeline
- Added FileHandle with persistent offset tracking

### ABI Stability
- Split kprint into 1-arg (Nim) and kwrite (C ABI)
- Fixed cstring conversion warnings across codebase
- Corrected RISC-V assembly (csrw sie, zero)

### Documentation
- Comprehensive Phase 8 documentation (docs/PHASE-8-ELF-LOADER.md)
- Detailed implementation notes and debugging status

## Current Status

✅ ELF parser, loader, and syscall infrastructure complete
✅ Test binary compiles and embeds in VFS
✅ Shell integration functional
🔧 Debugging command ring communication (syscall not reaching kernel)

## Files Changed

Core:
- core/loader.nim, core/loader/elf.nim (NEW)
- core/kernel.nim, core/ion.nim (syscall handling)
- core/fs/tar.nim (file cursor system)
- hal/arch/riscv64/switch.S (userland trampoline)

Userland:
- npl/nipbox/nipbox.nim (exec command)
- libs/membrane/libc_shim.zig (syscall implementation)
- libs/membrane/ion.zig (command ring API)

Build & Test:
- build.sh (hello.c compilation)
- rootfs/src/hello.c, rootfs/src/libnexus.h (NEW)
- apps/subject_entry.S (NEW)

## Next Steps

1. Debug SysTable and command ring communication
2. Verify ION fiber polling of chan_cmd
3. Test full ELF loading and execution flow
4. Add memory protection (future phase)

Co-authored-by:  <ai@voxisforge.dev>
 2025-12-31 20:18:49 +01:00