panicked at 'attempt to multiply with overflow'

[shzhxh]

When I run zCore on D1(Nazha) board, the kernel paniced, and I get those message:

panicked at 'attempt to multiply with overflow', ~/zCore/kernel-hal-bare/src/arch/riscv/mod.rs:518:26

The Code in mod.rs :

(time * 1_000_000_000 / FREQUENCY as u64)