Architecture

Relevant source files

The architecture section describes the implemented system on the unmerged feat/v0.5-runtime branch: subsystem boundaries, invariants, control flow, ownership and trust relationships. The branch adds an opt-in managed runtime (managed-runtime feature) for uploading, preparing, handing off and rolling back one signed 100 Hz controller; it is documented in its own Managed Runtime section, and the pages here describe where it touches the existing kernel. The canonical v0.5 contract is docs/plans/active/v0.5-bounded-runtime-evolution.md .

Page	What it covers
System Overview	Layering, authority order, runtime ownership, known assurance limits
Boot Flow	Limine (x86_64) and firmware/DTB (AArch64) entry through `kernel::init` to `/bin/init`
Memory	Physical allocator, heap sizing, `AddressSpace`, mapping transactions, TLB shootdown, user-copy boundary, fault policy
Kernel Crate Boundaries	Which crate or `kernel/src` module owns each policy
Scheduling & Locking	Per-CPU run queues, wait protocol, lock ranks, interrupt rules
Build Ownership	Root runner and `build.rs` vs. `xtask` vs. `scripts/`
Protocols & ABI	Syscall ABI v1, `sys_bpf` commands (including the managed commands 256 to 269), rk-bridge JSON stream, Shrike-link UART frames (including session, barrier and requalification messages)

Authority order

When documents disagree, the repository resolves them in this order (system-overview.md ):

Generated authorities under docs/reference/generated (ABI, targets, components, artifacts, build inputs, quality).
Accepted decisions under docs/decisions.
Current architecture documents.
Source code and its required gate evidence.
Archived and legacy documents (historical only).