// power: machine reset for QEMU `-M virt`.
//
// virt has no Pi power-manager; reset goes through PSCI. QEMU's virt
// machine advertises the PSCI conduit as HVC in its generated device tree
// (`psci { method = "hvc"; }`, confirmed via `-M virt,...,dumpdtb`) — NOT
// SMC, despite the CPU_ON comment in boot_quirks.S (that single-core path
// is a no-op and never issues the call, so its conduit was never tested).
// SYSTEM_RESET is function id 0x84000009 (PSCI 0.2+, no arguments). QEMU
// resets the machine; the call never returns.
//
// `hvc` / `smc` are gated by the assembler under `-mcpu baseline`
// ("instruction requires: el2 / el3"), so the conduit is emitted as its
// raw A64 encoding through `.inst`: hvc #0 = 0xD4000002. x0 carries the
// function id, pinned by the input constraint.

const PSCI_SYSTEM_RESET u64 = 0x8400_0009

pub fn reboot() noreturn {
    asm volatile (".inst 0xD4000002" // hvc #0
        :
        : [fn_id] "{x0}" (PSCI_SYSTEM_RESET),
        : .{ .memory = true })
    // PSCI SYSTEM_RESET does not return; spin if QEMU ever ignored it.
    while true {
        asm volatile ("wfe")
    }
}