Architecture

DipshitOS is a layered, freestanding kernel with no libc and no heap in the boot-critical paths — bounded fixed-BSS storage is the norm. This page is the map; the satellites below carry the detail.

The stack, top to bottom

┌───────────────────────────────────────────────┐
│  EL0 user programs + desktop apps (CALC.BIN,   │
│  NOTEPAD.BIN, DESKTOP.BIN, FETCH.BIN, …)      │
│  syscalls: ping/write/…/ipc/win/events/file/  │
│             exec/kill/tcp/fs (0–37)           │
├───────────────────────────────────────────────┤
│  Monitor + shell (dipshit>)                   │
│  Road Pops terminal · Driving Award compositor │
├───────────────────────────────────────────────┤
│  Scheduler (round-robin, 7 tasks) · processes │
│  Physical allocator · identity-map MMU        │
├───────────────────────────────────────────────┤
│  Drivers: virtio console/blk/entropy/gpu/net  │
│  + USB XHCI + HID · GICv3 · generic timer     │
├───────────────────────────────────────────────┤
│  UEFI boot loader (BOOTAA64.EFI)              │
└───────────────────────────────────────────────┘

What owns what

• Kernel overview — boot, ExitBootServices, exception vectors, the monitor and command registry.
• Memory model — the physical allocator, identity-map page tables, per-task address spaces.
• Userspace & syscalls — EL0, the frozen syscall ABI, fault-safe uaccess, exec and processes.
• Device drivers — the virtio surface, the XHCI USB controller, and the MMIO contracts.

Design discipline

Three rules show up everywhere:

1. Bounded static storage. Rings, FIFOs, window tables, and frame buffers are fixed-size BSS carve-outs. There is no general heap in the device paths; a full ring refuses or drops oldest, it does not grow.
2. One request at a time. Device queues are small (size 4) and drained polled — the project observes device behavior rather than assuming interrupt delivery, then records what it saw in docs/hardware-contract.md.
3. Evidence over assertion. Every subsystem has host tests (deterministic) and, where hardware is involved, a live Virtualization.framework gate. See Evidence & testing.

Subsystem boundaries in one line each