root / forevervigilantkernel/cap/src/lib.rs) is Rust, and security-critical paths are moving in that direction. Contributions welcome -- file issues or propose changes at exec/aegis.Capability-Based Security
Every process carries a 64-slot capability table. Every privileged syscall validates capabilities before execution. Rust-implemented validation core linked into the C kernel via FFI. Two-tier policy model with per-executable capability restriction on exec.
Monolithic Kernel
Single-address-space kernel in C targeting x86_64 long mode and AArch64. Higher-half mapping (0xFFFFFFFF80000000 on x86, 0xFFFF000000000000 on ARM). 4-level paging, bitmap PMM, kernel virtual allocator, per-process VMAs with copy-on-write fork. One shared VFS, scheduler, syscall table, and Rust capability core across both arches.
Full Network Stack
Ethernet, ARP, IP, TCP, UDP, ICMP. BSD socket API with UNIX domain sockets and epoll. Two NIC drivers: virtio-net for QEMU and RTL8169 for real hardware. DHCP client, HTTP server, and curl with BearSSL TLS.
Custom GUI
No X11. No Wayland. Direct framebuffer rendering via Lumen compositor, Glyph widget toolkit (TrueType text, buttons, text fields), Citadel desktop shell (taskbar, dock, window management), and Bastion graphical login manager.
Boots on Real Hardware
Aegis is not a QEMU-only experiment. Verified on bare-metal AMD x86_64 hardware (Ryzen 7 6800H dev machine, ThinkPad X13 Gen 1 test machine): boots cleanly through ACPI, brings up NVMe storage, full i8042 PS/2 bring-up, runs the full Lumen desktop. Limine replaced GRUB in v1.1.0 to fix AMD UEFI boot failures. The ARM64 port builds and boots under QEMU virt (cortex-a72/a76) through to the scheduler; it has no userland yet (pending an aarch64-musl toolchain) and Raspberry Pi 5 hardware support is deferred.
SMP & Preemption
Application processors come up via INIT-SIPI-SIPI with per-CPU GDT/TSS/LAPIC state. LAPIC timer-driven preemptive round-robin scheduling runs on the BSP; APs start but enter halt loops (single-core scheduling). Full context switch including FPU/SSE state (FXSAVE/FXRSTOR). Per-CPU run queues, work-stealing, and finer-grained locking are on the roadmap.
8 Filesystems
ext2 (read-write with block cache), ramfs, procfs, initrd, memfd, pipe, PTY, and console. Unified VFS layer with dentries, inodes, and per-process fd tables. GPT partition support on NVMe.
QEMU Integration Tests
Rust test harness boots the real kernel in QEMU, captures serial output, asserts boot sequences, drives GUI interactions via HMP mouse/keyboard injection, and performs fuzzy visual regression testing on screendumps.
Full Userspace
Vigil init system with service management. Capability-aware secure shell (stsh). 40+ coreutils. Text and graphical installers. musl libc 1.2.5 dynamic linking. Web server, DHCP client, text editor. Herald package manager with signed .hpkg packages and Chancery repository support.
Documentation
Overview
- Architecture Overview – High-level system diagram, subsystem map, boot sequence, and documentation index
- Philosophy – What Aegis is for, the principles behind it, and the make-it-exist-first development cycle
Kernel Internals
- Boot Process – Multiboot2 entry, 32-to-64-bit transition, higher-half setup, and full initialization sequence
- Memory Management – Physical memory manager (bitmap), virtual memory manager (4-level paging), kernel virtual allocator, user VMAs
- Scheduler – Round-robin preemptive scheduling, SMP, context switch, wait queues
- Processes & ELF – Process model, ELF64 loading, fork/exec, dynamic linking
- Syscall Interface – Complete syscall reference (100+ calls across 15 categories)
- Interrupts & Exceptions – IDT, PIC, LAPIC/IOAPIC, exception handlers, IRQ routing
- Observability & Debugging – printk & kernel log, symbolized panic backtraces, in-kernel symbol table, stackshot, SysRq-over-serial, KASSERT, make trace
Security
- Capability Model – Per-process capability tables, Rust validation core, C/Rust FFI boundary
- Security Policy Engine – Policy file format, baseline capabilities, inheritance on fork/exec
Filesystems
- VFS Layer – Virtual filesystem architecture, inode/dentry model, mount points
- ext2 Implementation – On-disk layout, block cache, directory operations, read-write support
- procfs & Special Filesystems – procfs, ramfs, memfd, pipe, PTY
Networking
- Network Stack – Architecture, packet flow, device abstraction
- TCP/IP – TCP state machine, IP routing, ICMP, ARP
- Socket API – BSD socket interface, UNIX sockets, epoll
Drivers
- Driver Overview – NVMe, xHCI, USB HID, virtio-net, RTL8169, framebuffer, PCI enumeration
Graphics
- Lumen Compositor – Display server, window management, framebuffer rendering, mouse input
- Glyph Toolkit – Widget library, TrueType rendering, layout, focus management
- Citadel Desktop – Desktop shell, taskbar, dock, window decorations
Userspace
- Vigil Init System – PID 1 service manager, service files, vigictl
- Shell & Coreutils – Secure shell (stsh), minimal shell, 25+ utilities
- Services – httpd, dhcp, chronos, curl, rune, installers
- Herald Package Manager – Signed .hpkg packages, Chancery repositories, CAP_KIND_INSTALL enforcement
Development
- Build System – Makefile architecture, cross-compilation, rootfs construction, ISO packaging
- Testing Framework – QEMU-based integration tests, visual regression, installer verification