// PORT TARGET: arch/src/lib.rs (top-level), routes to aarch64
// Source size: ~150 LOC entry, then ~3500 LOC under aarch64/
// Status: skeleton (no impl)
// aarch64 boot/FDT/GIC layout — only on aarch64 (pulls `vm-fdt`). The x86_64
// boot path lands under `arch/x86_64` with the KVM backend.
// x86_64 boot protocol (boot_params/e820/GDT/long-mode) — only on x86_64,
// where the KVM backend uses it. Pure logic over guest RAM; no KVM dependency.