BRAIDGROUP
RESEARCH & DEV
Architecture

Bare Metal.
Full Stack.

An x86_64 operating system kernel with SMP, ACPI, VFS, networking, device drivers, and a complete userspace. Boots from Multiboot2, runs ELF binaries, and handles hardware directly.

Kernel Core

What Boots.

Boot Sequence

Multiboot2 header, GDT, IDT, serial console, heap initialization, AP trampoline for SMP. Boots to a userspace ELF shell.

Memory Management

4-level paging (PML4), Higher Half Direct Map at 0xFFFF800000000000, K&R heap allocator, VMM with fork/deep-copy for process isolation.

Process Scheduling

O(1) multi-queue priority scheduler with 3 priority levels, time-slicing, aging/demotion, preemption, and spinlock-protected per-CPU state.

ELF Loader

ELF64 binary parser with PT_LOAD segment mapping, BSS zeroing, and address space setup. Loads userspace binaries directly into virtual memory.

POSIX Signals

22 signals (SIGHUP through SIGTTOU) with per-process signal dispatch, pending signal queues, and handler registration.

IPC

Message-based inter-process communication with per-process message queues, typed messages, and IRQ notification support.

Hardware Support

Talks to Real Hardware.

ACPI for power management, SMP for multi-core, APIC for interrupts, and drivers for storage, networking, and graphics.

System

ACPI

RSDP/XSDT/MADT parsing, CPU discovery (up to 32 cores), IOAPIC address extraction, shutdown/reboot

SMP

INIT-SIPI-SIPI sequence, per-CPU GDT/TSS/IDT, GS-base per-cpu data, up to 32 CPUs

Local APIC

MMIO-based timer at 100Hz, EOI, IPI send, LINT configuration

IOAPIC

IRQ redirection, mask/unmask, legacy IRQ remapping (keyboard→33, mouse→44)

Security

SMEP

Supervisor Mode Execution Prevention — detected via CPUID, enabled in CR4

Stack Canary

0xDEADBEEF guard value with __stack_chk_fail halt on corruption

User Pointer Validation

Canonical address range checks before kernel access

Capability Model

Per-process capability bitmask with root-all override

Filesystems

FAT32

Read/Write

Full implementation: cluster allocation, directory traversal, FAT chain walking, multi-FAT mirroring.

ext2

Read-Only

Inode read, block mapping (direct/indirect/double), directory traversal, file read.

VFS Layer

In Development

Path resolution, mount points, auto-probing (tries ext2 then FAT32), MBR + GPT partition scanning.

Networking

TCP/IP Stack

In Development

Ethernet → ARP → IPv4 → UDP (full) / TCP (partial) → DNS (A records) → DHCP (full DORA handshake).

DHCP Client

In Development

Full Discover → Offer → Request → ACK four-way handshake with option parsing (subnet, router, DNS).

DNS Resolver

In Development

A record resolution over UDP port 53 with label encoding and answer parsing.

Device Drivers

15 Driver Categories.

AHCI (SATA)

Full

DMA, PRDT, identify, port probing

NVMe

Full

Admin/IO queues, PRP, namespace discovery

Intel E1000

Full

MMIO, RX/TX rings, DMA, MAC read

virtio-net

Present

Virtual network device

VESA Framebuffer

Full

Pixel write, fill rect, blit

virtio-gpu

Present

Virtual GPU device

xHCI (USB)

Init

Controller reset, port scan, rings

PS/2 Input

Full

Keyboard, trackpad, touchscreen

ACPI Battery

Present

Battery info via ACPI

ACPI Thermal

Present

Thermal zone monitoring

HDA Audio

Present

High Definition Audio

PCI Enumeration

Full

Bus scan, device discovery

Syscall Interface

140+ Syscalls.

A POSIX-like syscall interface with process management, IPC, graphics, networking, device access, and compatibility layers for Windows NT and Linux.

Core (0-41)

YIELD, EXIT, SPAWN, READ, WRITE, OPEN, CLOSE, IPC_SEND/RECV, SBRK, BITBLT, DRAW, EXEC, MAP/UNMAP_MEMORY, FORK, EXECVE, WAITPID, CLOCK_GETTIME, NANOSLEEP

Extended (70-140)

CLIPBOARD, PIPE, DUP2, MMAP, IOCTL, SELECT, POLL, GETUID, CHMOD, WIFI_SCAN/CONNECT, BT_SCAN/PAIR, DRM_IOCTL, CAMERA_OPEN/READ, BATTERY_INFO, CPUFREQ, AI_INFERENCE, PERF_OPEN

Compatibility

Windows NT compat (NT_CREATE_FILE, NT_WRITE_FILE, NT_READ_FILE) and Linux compat (LINUX_READ, WRITE, OPEN, CLOSE, STAT) for binary compatibility.

Userspace SDK

Build Userspace Apps.

SDK with syscall wrappers, graphics, input handling, game engine helpers, and 16 media codec implementations.

Syscall Wrappers

40+ C functions wrapping kernel syscalls: file I/O, memory mapping, process control, IPC, graphics primitives.

Media Decoders

AAC, AV1, BMP, FLAC, H.264, H.265, JPEG, MKV, MP3, MP4, Opus, PDF, PNG, VP9, WAV, WebP — all in userspace.

Graphics & Vulkan

Vulkan API headers and implementation, framebuffer abstraction, game engine toolkit with 3D math.

From Boot to Userspace.

The kernel is the foundation of the full Braid OS stack. Build an ISO, boot in QEMU, and run userspace binaries.

Read the Docs →Read the Whitepaper →