Method handle_ecall

crates/virtual-machine/src/cpu/pipeline.rs:793–803

(&mut self, _bus: &mut SystemBus)

            PrivilegeMode::Machine => traps::CAUSE_ECALL_M,
        };
        self.take_trap(cause, 0, ecall_pc);
        self.flush_pipeline();
        Ok(TickOutcome::EcallSquash)
    }

    // Returns Some((cause, tval, pc)) when an interrupt is ready to fire right now.
    // Priority order per spec: MEI(11) > MSI(3) > MTI(7), then SEI(9) > SSI(1) > STI(5).
    fn check_pending_interrupt(&self) -> Option<(u64, u64, u64)> {
        let pending = self.csrs.mip & self.csrs.mie;
        if pending == 0 {
            return None;
        }

        let in_m = self.regs.priv_mode == PrivilegeMode::Machine;