← metal

PiOS

Bare-metal OS for the Pi 5. ~240KB kernel. No Linux.

⌥ repo

A deterministic microkernel. No Linux. No libc. 4 dedicated CPU cores. Every byte of RAM, every CPU cycle, every hardware register — under your direct control.

Core architecture

  • Core 0 — Kernel services + Network + Disk
  • Cores 1-3 — User schedulers with preemptive 5ms quanta
  • Each core gets 16MB private RAM
  • 16 lock-free SPSC ring buffers for inter-core messaging

What's running

NetworkIP/TCP/UDP/ICMP/ARP/DNS — hardened, no fragmentation
StorageSDHCI driver + WALFS append-only filesystem
DisplayHDMI 1024×768 framebuffer + UART serial console
ComputeNEON/SIMD + DMA scatter-gather + QPU tensor dispatch
USBxHCI host via RP1 — HID keyboard + mass storage
SecurityEL2→EL1 boot, capsule isolation, capability-gated pipes

Unified pipes

/ipc, /net, /fs, /hw — all domains mapped through capability-gated pipe adapters. Everything is a stream.

When you own every cycle, latency becomes a choice, not an accident.

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