// PORT TARGET: arch/src/aarch64/mod.rs + submodules
// Source size: ~3500 LOC
// Status: skeleton (no impl)
//
// Responsibilities:
// layout.rs — guest physical memory map (RAM base, MMIO base, ...)
// fdt.rs — FlatDT generation (cpus, memory, gic, virtio nodes)
// regs.rs — sysreg / GP-reg constants + boot register staging
// gicv3.rs — GIC distributor/redistributor MMIO layout