Boot Path
Multiboot-compliant startup via GRUB with clean assembly handoff into C kernel entry.
x86 Bare-Metal Project
Project SigmaBoot ALPHA
A tiny operating system kernel focused on clarity: Multiboot startup, VGA terminal, PS/2 keyboard and mouse input, lock-state LEDs, and release-ready CI.
Warning: Experimental alpha software. Features and behavior may change without notice.
kernel.iso boot preview
PROJECT SIGMABOOT
Kernel booted successfully.
Keyboard input is ready (IRQ1 interrupt-driven, US scancodes).
PS/2 mouse driver is ready (IRQ12 packet streaming). Use 'mouse' for state.
Type below:
> hello world
LOCKS CAPS:OFF NUM:ON SCRL:OFF M:--- P:12
Core Features
VGA Terminal
Text rendering, color controls, tab/newline/backspace support, and scroll-safe output zone.
Keyboard
IRQ1 interrupt-driven PS/2 input, US scancode translation, lock key behavior, LED synchronization, and a heap-backed input queue with fallback.
Status Bar
Persistent bottom-row lock-state display with CAPS/NUM/SCRL, live mouse activity (`M:... P:...`), and uptime (`T+Xs`).
Build and Run
Use the ISO directly. Do not extract it to boot.
Local Commands
make -C kernel all
make -C kernel iso
qemu-system-i386 -cdrom kernel/build/kernel.isoBoot From Release Asset
qemu-system-i386 -cdrom kernel.isoFor hardware, write kernel.iso directly to USB with Rufus or Balena Etcher.
Release Pipeline
GitHub Actions builds kernel.bin, kernel.elf, and kernel.iso, then attaches downloadable artifacts to each published release.
- Tag used: v0.0.20260405
- CI artifacts: workflow run downloads
- Release assets: direct downloads for users
- Latest milestone: first PS/2 mouse driver (IRQ12), live status-bar activity indicator, and host-side mouse tests
Roadmap
Done: VGA terminal, keyboard lock LEDs, lock status bar, and IRQ1 interrupt-driven input (IDT + PIC remap).
Done: CI build artifacts, release asset pipeline, and project website/docs with GitHub Pages deployment.
Done: exception ISRs with a fault diagnostics screen (vector/name/error code/EIP/CS/EFLAGS).
Done: PIT timer IRQ0 and uptime display integrated into the status bar.
Done: tiny command shell (`help`, `clear`, `version`, `locks`, `uptime`).
Done: Multiboot memory map viewer command (`memmap`) for boot-time physical layout visibility.
Done: early physical memory manager groundwork with bitmap frame tracking and `pmm` stats.
Done: heap allocator groundwork (`kmalloc`/`kfree`) backed by PMM frames with `heap` stats.
Done: dynamic shell command buffer migrated to heap-backed allocation with growth and history.
Done: keyboard IRQ queue migrated to heap-backed allocation with static fallback.
Done: decimal print formatting buffer migrated to heap-backed allocation with static fallback.
Done: memmap line composition migrated to a reusable heap-backed scratch buffer with stack fallback.
Done: exception diagnostics formatting migrated to a heap-backed workspace buffer with static fallback.
Done: PMM stats line formatting migrated to a heap-backed buffer with stack fallback.
Done: heap stats line formatting migrated to a heap-backed buffer with stack fallback.
Done: shared stats and diagnostics formatting consolidated into a dedicated `stats_util` module.
Done: allocator diagnostics expanded with `heapfrag` fragmentation view and deterministic `heapstress [rounds]` stress runs.
Done: allocator leak-trace and per-size live allocation histogram diagnostics added (`heapleaks`, `heaphist`).
Done: lightweight heap integrity checks added for corrupted headers and split/merge invariant mismatches (`heapcheck`).
Done: allocator corruption injection tests added for negative-path validation of integrity diagnostics.
Done: integrity fault details are exposed in a compact shell diagnostics summary command (`heaptriage`) for faster triage.
Done: host-side coverage reached 100% for heap allocator, diagnostics, and formatter test paths.
Done: first PS/2 mouse driver integrated on IRQ12 with packet decode, shell state command (`mouse`), and a live status-bar activity indicator.
Done: host-side PS/2 mouse driver tests added and wired into test/coverage pipelines (`mouse_test`).
Next: add a shell-accessible heap corruption injection command so triage output can be exercised without recompiling.
